Assessment of Fuel Economy Technologies for Light-Duty Vehicles 0309156076, 9780309156073

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ASSESSMENT OF FUEL ECONOMY TECHNOLOGIES FOR LIGHT-DUTY VEHICLES

Committee on the Assessment of Technologies for Improving Light-Duty Vehicle Fuel Economy Board on Energy and Environmental Systems Division on Engineering and Physical Sciences

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

THE NATIONAL ACADEMIES PRESS

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NOTICE: The project that is the subject of this report was approved by the Governing Board of the National R esearch Council, whose m em bers are drawn from the councils of the National A cadem y of S ciences, the National A cadem y of Engineering, nd thea Institute of M edicine. The m em bers of the com m ittee responsible for the report were chose n for their special com petences and with regard for appropriate balance. This study was supported by Contract No. D TNH 2 H 2 - -00 70 - 1 5 5 between the National A cadem y of S ciences and the D epartm ent of Transportation. ny opinions, A indings, conclusions, or recom m endations ex pressed in this publication are those of the author( s) and do not necessarily relect the views of the organiz ations or agency that providedsupport for the project. International S tandard Book Num ber- 1 3 : 9 7 86 -00 7- 3- 30 9 - 1 5 International S tandard Book Num ber- 1 0 : 0 - 3 60 9 - 1 5 6 0 7 L ibrary of Congress Control Num ber: 2 0 1 1 9 2 7 6 3 9 Copies of this report are available from the Nation al A cadem ies P ress, 5 0 0 F ifth S treet, N. W . , L ock box 2 8 5 , W ashington, D C 2 0 0 5 5 ; ( 8 00 20 )) 36 32 44 --36 32 14 32 (or in(the 2 W ashington m etropolitan area) ; Internet, http:/ / www. nap. edu. Copyright 2 0 1 1 by the National A cadem y of SAciences. ll rights reserved. P rinted in the U nited S tates of A m erica

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

The National Academy of Sciences is a private, nonproit, self- perpetuating society of distinguished scholars engaged in scientiic and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. U pon the authority of the charter granted to ityb the Congress in 1 8 6 3 , the A cadem y has a m t andate req uires thait to advise the federal governm ent on scientiic and technical m atters. D r. R alphcerone J . Ciis president of the National A cadem y of S ciences. The National Academy of Engineering was established in 1 9 6 4 , under the charter ofNational the A cadem y of S ciences, as a parallel organiz ation outstanding of engineers. It is autonom ous in its adm inistration and in the selection of its m em sharing bers, with the National A cadem y of S ciences the responsibility for advising the federal government. The National A cadem y of Engineering also sponsors engineering program s aim ed at m eeting onal natineeds, encourages education and research, and recogniz es the superior achievem ents of enginee rs. D r. Charles M . V est is president of the National A cadem y of Engineering. The Institute of Medicine was established in 1 9 7 0 by the National A cadem S ciences y of to secure the services of em inent m em bers of appropriateessions prof in the ex am ination of policy m atters pertaining to the health of the public. The Institute acts under the responsibility given to the National A cadem y of S ciences by its congressional charter betoan adviser to the federal governm ent and, upon its own initiative, to identify issues of m edi cal care, research, and education. D r. H arvey V . F ineberg is president of the Institute of M edicine. The National Research Council was organiz ed by the National A cadem y of S ciences in 1 9 1 6 to associate the broad com m unity of science and techn ology with the A cadem y’s purposes of furthering k nowledge and advising the federal governm ent. Ftioning unc in accordance with general policies determ ined by the A cadem y, the Council has becom incipal e the properating agency of both the National A cadem y of S ciences and the National A cadem ineering y of Engin providing services to the governm ent, the public, and the scientiic and engineering com m unities. The Council is adm inistered jointly by both A cadem ies and the Institute of M edicine. . R Dalph r J . Cicerone and D r. Charles M . V est are chair and vice chair, respectively, of the NationalR esearch Council. www.national-academies.org

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

COMMITTEE ON THE ASSESSMENT OF TECHNOLOGIES FOR IMPROVING LIGHT-DUTY VEHICLE FUEL ECONOMY TR EV OR O. J ONES 1 ,ElectroS NA E, onics M edical, Cleveland, Ohio, Chair TH OM A S W . A S M U S , NA E, D aim retired) lerChrysler , Oak Corporation land, M ( ichigan R OD ICA BA R A NES CU , NA E, NA V IS TA ois R , W arrenville, Illin J A Y BA R ON, Center for A utom otive R esearch, r, MA ichigan nn A rbo D A V ID F R IED M A N, U nion of Concerned ington, S cientists, D . C.W ash D A V ID GR EENE, Oak R idge National L aboratory, dge, Tennessee Oak R i L INOS J A COV ID ES , NA E, D elphi R esearch etired) L aboratory , Grosse P ( r ointe F arm s, M ichigan J OH N H . J OH NS ON, M ichigan Technological HU oughton niversity, J OH N G. K A S S A K IA N, NA E, M assachusetts Technology, Institute Camof bridge R OGER B. K R IEGER , U niversity of W isconsin- M adison GA R Y W . R OGER S , F EV , Inc. , A uburn H ills, M ichigan R OBER T F . S A W Y ER , NA E, U niversity rk ofeley California, Be Staff K . J OH N H OL M ES , S tudy D irector A L A N CR A NE, S enior P rogram Oficer L aNITA J ONES , A dm inistrative Coordinator M A D EL INE W OOD R U F F , S enior P rogram Oficer E. J ONA TH A N Y A NGER , S enior P roject A ssistant J A M ES J . Z U CCH ETTO, D irector, Board on nvironm Energy ental and ES ystem s

1 NA

E, National A cadem y of Engineering.

v

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

BOARD ON ENERGY AND ENVIRONMENTAL SYSTEMS 1. D A ND R EW BR OW Chair, N, NA J R E, , elphi Corporation, Troy, M ichigan R A K ES H A GR A W A L , NA E, P urdue U tte, niversity, Indiana W est L afaye W IL L IA M BA NH OL Z ER , NA E, The D ow Chem idland, ical M Com ichigan pany, M M A R IL Y N BR OW N, Georgia Institute of Technology, anta A tl M ICH A EL COR R A D INI, NA E, U niversity ison of W isconsin- M ad P A U L D eCOTIS , L ong Island P ower A uthority, New Y Aorklbany, CH R IS TINE EH L IG- ECONOM ID ES , NA E, Tex ty, as A College & MS tation U niversi W IL L IA M F R IEND , NA E, Bechtel Group,irginia Inc. , M cL ean, V S H ER R I GOOD M A N, CNA , A lex andria, V irginia NA R A IN H INGOR A NI, NA E, Independent Consultant, A ltos H Lills, os California R OBER T H U GGETT, Independent Consultant, S eaford, rginia V i D EBBIE NIEM EIER , U niversity of California, D avis D A NIEL NOCER A2 M , NAassachusetts S , Institute of Technology, Cam bridge M ICH A EL OP P ENH EIM ER , P rinceton U n,niversity, New J ersey P rinceto D A N R EICH ER , S tanford U niversity, S tanford, nia Califor BER NA R D R OBER TS ON, NA E, D aim lerChrysler Bloom ield ( retired) H ills, , M ichigan A L IS ON S IL V ER S TEIN, Consultant, P lugerville, Tex as M A R K TH IEM ENS , NA S , U niversity ofiego California, S an D R ICH A R D W H ITE, Oppenheim er & Com pany, New Y ork City

Staff J A M ES Z U CCH ETTO, D irector D A NA CA INES , F inancial A ssociate A L A N CR A NE, S enior P rogram Oficer J ONNA H A M IL TON, P rogram Oficer K . J OH N H OL M ES , S enior P rogram Oficer Board and D A irector ssociate L aNITA J ONES , A dm inistrative Coordinator A L ICE W IL L IA M S , S enior P rogram A ssistant M A D EL INE W OOD R U F F , S enior P rogram Oficer J ONA TH A N Y A NGER , S enior P rogram A ssistant

1 National 2National

A cadem y of Engineering. A cadem y of S ciences.

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Assessment of Fuel Economy Technologies for Light-Duty Vehicles

DEDICATION This report is dedicated to D r. P atrick F lynn, ry active a ve and contributing com m ittee m em ber and a m em ber of the National A cadem neering, y of Engi who passed away on A ugust 2 1 , 2 0 0 8 , while this report was being ed. prepar

vii

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Acknowledgments

A s a result of the considerable tim e and effort tributed con Environm ental A nalysis, Inc. ; R icardo, Inc. ;S and , Inc. IBI by the m em bers of the Com mon ittee the A ssessm ent of Tech- The com m ittee also thank s Christopher Baillie, FInc.EV , , nologies for Im proving L ight- D uty V ehicle F om uel Econ y, an unpaid consultant to the com m ittee, for his m any efforts, whose biographies are presented in A ppendix A , report this dedication, and hard work . identiies and estim ates the effectiveness of techno logies for This report has been reviewed in draft form by indi im proving fuel econom y in light- duty vehicles, the andreviduals chosen for their diverse perspectives and technical lated costs. The com m ittee’s statem ent of taskendix ( A B) pp ex pertise, in accordance with procedures approved yb the clearly presented substantial challenges, which thecom m ittee R eport R eview Com m ittee of the NR C. The purpose this of confronted with fair and honest discussion supported with independent review is to provide candid and critical com data from the National H ighway Trafic S afety A stradm ini m ents that will assist the institution in m ak ing s published it tion ( NH TS A ) , the Environm ental P rotectionEP A Agency ) , (report as sound as possible and to ensure that the report m eets and the D OT- V olpe R esearch L aboratory. I appreciate the institutional standards for objectivity, evidence,and responm em bers’ efforts, especially those who chairedsubgroups the siveness to the study charge. The review com m ents nd draft a and led the com pilation of the various chapters. m anuscript rem ain conidential to protect the integr ity of the The data and conclusions presented in the report have deliberative process. beneited from a substantial am ount of inform ation rovided p W e wish to thank the following individuals for thei r by global autom obile m anufacturers, suppliers, others and review of this report: in the regulatory com m unities and in non- governm al ent organiz ations. A ppendix C lists the presentations rovided p Tom A ustin, S ierra R esearch Corporation, to the com m ittee. M em bers of the com m ittee ited also vis P aul Blum berg, Consultant, industry organiz ations in North A m erica, Europe, d J apan. an A ndrew Brown, D elphi Corporation, In addition, the National R esearch Council contract ed with W ynn Bussm ann, D aim lerChrysler Corporation) (, retired outside organiz ations to develop and evaluate a number of L aurence Caretto, California S tate U niversity, technological opportunities. Coralie Cooper, NES CA U M , The com m ittee greatly appreciates and thank s the di-de J am es F ay, M assachusetts Institute of Technology, cated and com m itted staff of the National R esearch Council L arry H owell, Consultant, ( NR C) , and speciically the Board on Energy and Envi D avid J apik se, Concepts NR EC, ronm ental S ystem s ( BEES ) under the directionesof J am Orron K ee, National H ighway Trafic S afety A dm a- inistr Z ucchetto ( director of BEES ) . The com m itteelarly particu tion ( retired) , wishes to recogniz e the outstanding leadership of K. J ohn S teven P lotk in, A rgonne National L aboratory, H olm es, study director, and his staff. Thank secogniand r P riyaranjan P rasad, P rasad Consulting, and tion are due to the following BEES staff: A lan Cran e, senior L ee S chipper, Berk eley Transportation Center. program oficer; M adeline W oodruff, senior program oficer; L aNita J ones, adm inistrative coordinator; J onathan Y anger, A lthough the reviewers listed above have provided m any senior program assistant; and A aron Greco, M irz P olicy ayan constructive com m ents and suggestions, they weret no F ellow, as well as consultants K . G. D uleep ofyEnerg and ask ed to endorse the conclusions or recom m endations , nor

ix

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

x

ACKNOWLEDGMENTS

did they see the inal draft of the report before its release. that all review com m ents were carefully considered. R esponThe review of this report was overseen by Elisabeth M . sibility for the inal content of this report rests entirely with D rak e, M assachusetts Institute of Technologyred) ( reti , and the authoring com m ittee and the institution. D ale S tein, M ichigan Technological U niversity red)( .reti A ppointed by the NR C, they were responsible forkminga Trevor O. J ones,Chair certain that an independent ex am ination of this rep ort was Com m ittee on the A ssessm ent of Technologies carried out in accordance with institutional procedures and for Im proving L ight- D uty V ehicle F uel Econom y

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Contents

S U M M A R Y

1

1

INTR OD U CTION Current P olicy Contex t and M otivation, 9 S tatem ent of Task , 1 0 Contents of This R eport, 1 0 R eferences, 1 1

9

2

F U ND A M ENTA L S OF F U EL CONS U M P TION Introduction, 1 2 F uel Consum ption and F uel Econom y, 1 2 Engines, 1 4 F uels, 1 6 F uel Econom y Testing and R egulations, 1 7 Custom er Ex pectations, 1 8 Tractive F orce and Tractive Energy, 1 9 D etailed V ehicle S im ulation, 2 1 F indings and R ecom m endations, 2 2 R eferences, 2 3

1 2

3

COS T ES TIM A TION Introduction, 2 4 P rem ises, 2 5 Com ponents of Cost, 2 6 F actors A ffecting Costs over Tim e and A cross acturers, M anuf 2 7 M ethods of Estim ating Costs, 2 8 R etail P rice Eq uivalent M ark up F actors, 3 2 F indings, 3 6 R eferences, 3 6

2 4

4

S P A R K - IGNITION GA S OL INE ENGINES Introduction, 3 8 S I Engine Eficiency F undam entals, 3 8 Therm odynam ic F actors, 4 0 V alve- Event M odulation of Gas- Ex change P rocesses, 4 0 Gasoline D irect Injection, 4 8 D ownsiz ed Engines with Turbocharging, 4 9 Engine F riction R eduction Efforts, 5 2 Engine H eat M anagem ent, 5 3

3 8

xi

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

xii

CONTENTS

H om ogeneous- Charge Com pression Ignition, 5 4 Com bustion R estart, 5 4 Ethanol D irect Injection, 5 4 F indings, 5 5 Bibliography, 5 6 A nnex , 5 8 5

COM P R ES S ION- IGNITION D IES EL ENGINES Introduction, 6 1 Technologies A ffecting F uel Consum ption, 6 2 F uel Consum ption R eduction P otential, 6 8 Technology R eadiness/ S eq uencing, 7 2 Technology Cost Estim ates, 7 3 F indings, 8 0 R eferences, 8 2 A nnex , 8 3

6 1

6

H Y BR ID P OW ER TR A INS Introduction, 8 4 H ybrid P ower Train S ystem s, 8 4 Battery Technology, 8 8 P ower Electronics, 9 1 R otating Electrical M achines and Controllers, 9 1 Cost Estim ates, 9 3 F uel Consum ption Beneits of H ybrid A rchitectures, 9 4 F uel Cell V ehicles, 9 5 F indings, 9 5 R eferences, 9 6 A nnex , 9 7

8 4

7

NON- ENGINE TECH NOL OGIES Introduction, 9 9 Non- Engine Technologies Considered in This S tudy, 9 9 F uel Consum ption Beneits of Non- Engine Technologie s, 1 0 6 Tim ing Considerations for Introducing New Technolo gies, 1 0 9 Costs of Non- Engine Technologies, 1 1 1 S um m ary, 1 1 4 F indings, 1 1 6 R eferences, 1 1 6

9 9

8

M OD EL ING IM P R OV EM ENTS IN V EH ICL E F U EL CONS 1U 1 M 8 P TION Introduction, 1 1 8 Challenges in M odeling V ehicle F uel Consum ption, 1 9 1 M ethodology of the 2 0 0 2 National R esearch R Council eport, 1 1 9 M odeling U sing P artial D iscrete A pprox im od, ation 1 M 2 3 eth M odeling U sing F ull S ystem S im ulation, 1 3 1 A n A nalysis of S ynergistic Effects A m ong Technolog ies U sing F ull S ystem S im ulation, 1 3 3 F indings, 1 3 5 R eferences, 1 3 6

9

A P P L ICA TION OF V EH ICL E TECH NOL OGIESA TO S VS ES EH ICL E CL 1 3 8 Introduction, 1 3 8 D eveloping Baseline V ehicle Classes, 1 3 8 Estim ation of F uel Consum ption Beneits, 1 4 0 A pplicability of Technologies to V ehicle Classes, 1 4 1

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

xiii

CONTENTS

Estim ating Increm ental Costs A ssociated with Techn ology Evolution, 1 4 1 A ssessing P otential Technology S eq uencing P 4aths, 4 1 Im provem ents to M odeling of M ultiple F uel Econom Technologies, y 1 5 3 F indings and R ecom m endation, 1 5 5 Bibliography, 1 5 6

A P P END IX ES A B C D E F G H

Com m ittee Biographies S tatem ent of Task L ist of P resentations at P ublic Com m ittee M s eeting S elect A cronym s Com parison of F uel Consum ption and F uel Econom y R eview of Estim ate of R etail P rice Eq uivalent k up M F actors ar Com pression- Ignition Engine R eplacem ent forS Fizulle P ick up/ S U V Other NR C A ssessm ents of Beneits, Costs, and iness R ofead F uel Econom y Technologies I R esults of Other M ajor S tudies J P robabilities in Estim ations of F uel Consum Beneits ption and Costs K M odel D escription and R for esults the EEA - ICF M odel

1 1 1 1

5 9 6 3 6 5 6 7 6 9 1 1 7 1 1 7 7

1 8 1 1 8 9 2 0 8 2 1 0

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Summary

In 2 0 0 7 the National H ighway Trafic S afety A dm additional inisanalysis are warranted. Given that the ultim ate tration ( NH TS A ) req uested that the National Aes cademenergy i savings are directly related to the am ount fofuel provide an objective and independent update of the techconsum ed, as opposed to the distance that a vehicle travels nology assessm ents for fuel econom y im provem dents anon a gallon of fuel, consum ers also will be helped by addition increm ental costs contained in the 2 0 0 2 National search R e to the label of ex plicit inform ation that speciies the num ber Council ( NR C) report Effectiveness and Imp act o f Co rp o rateof gallons typically used by the vehicle to travel 1 0 0 m iles. Averag e F u el Eco no my ( CAF E) The Standards. NH TS A also ask ed that the NR C add to its assessm ent technologi es that Technologies for Reducing Fuel Consumption have em erged since that report was prepared. To add ress this req uest, the NR C form ed the Com m ittee on the m Aentssess Tables S . 1 and S . 2 show the com m ittee’s estim f ates o of Technologies for Im proving L ight- D uty V ehicle el F fuel u consum ption beneits and costs for technologiesthat Econom y. The statem ent of task , shown in A ppendix , are B com m ercially available and can be im plem ented ithin w directed the com m ittee to estim ate the eficacy, t, and cos 5 years. The cost estim ates represent estim ates theforcurapplicability of technologies that m ight be used ov er the rent ( 2 0 0 9 / 2 0 1 0 ) tim e period to aboute 5future. years in th nex t 1 5 years. The com m ittee based these estim ates on a variety sources, of including recent reports from regulatory agenciesnd a other sources on the costs and beneits of technologies; estim ates FINDINGS AND RECOMMENDATIONS obtained from suppliers on the costs of com ponents; discussions with ex perts at autom obile m anufacturers supand Overarching Finding pliers; detailed teardown studies of piece costs for individual A signiicant num ber of technologies ex ist thatreduce can technologies; and com parisons of the prices for and am ount the fuel consum ption of light- duty vehicles whileaintainm of fuel consum ed by sim ilar vehicles with and witho ut a ing sim ilar perform ance, safety, and utility. technology Each particular technology. has its own characteristic fuel consum ption beneit and estiS om e longer- term technologies have also dem donstrate m ated cost. A lthough these technologies are often onsidered c the potential to reduce fuel consum ption, although further independently, there can be positive and negative interactions developm ent is req uired to determ ine the degree imofproveam ong individual technologies, and so the technolog ies m ent, cost- effectiveness, and ex pected durability. These m ust be integrated effectively into the full vehicl e system . technologies include cam less valve trains, hom ogene ousIntegration req uires that other com ponents of the ehicle v be charge com pression ignition, advanced diesel, plugin added or m odiied to produce a com petitive vehicle hat tcan hybrids, diesel hybrids, electric vehicles, fuel ce ll vehicles, be m ark eted successfully. Thus, although the fuel onsum c pand advanced m aterials and body designs. A lthough om s e tion beneits and costs discussed here are com paredagainst of these technologies will see at least lim ited com m ercial those of representative base vehicles, the actual costs and introduction over the nex t several years, it is onl y in the 5 - to beneits will vary by speciic m odel. F urther, the neits be of 1 5 - year tim e fram e and beyond that they are ex d topecte ind som e technologies are not com pletely represented in the tests widespread com m ercial application. F urther, itnot will be used to estim ate corporate average fuel econom y (FCA E) . possible for som e of these technologies to becom olutions es The estim ate of such beneits will be m ore realistic using the for signiicant technical and econom ic challenges,nda thus new ive- cycle tests that display fuel econom y data on new som e of these technologies will rem ain perennially 1 0 to 1 5 vehicles’ labels, but im provem ents to test procedur es and years out beyond a m oving reference. A m ong itsisions, prov 1

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

TA BL E S . 1 Com m ittee’s Estim ates of Effectiveness hown as a (percentage) s of Near- Term V ehicle F uel Consum ption

TechnologiesRin educing

Incremental values - A preceding technology must be included

Technologies

I4

Spark Ignition Techs

Abbreviation

Low Friction Lubricants

LUB

Low 0.5

High 0.5

Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete V ariable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP)

EFR CCP DVVL DEAC ICP DCP

0.5 1.5 1.5 NA 1.0 1.5

2.0 3.0 3.0 NA 2.0 2.5

Discrete V ariable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV

DVVL CVVL DEAC

1.5 3.5 NA

3.0 6.0 NA

VVT - Coupled Cam Phasing (CCP), OHV Discrete V ariable Valve Lift (DVVL), OHV Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel Techs

CCP DVVL SGDI TRBDS

1.5 1.5 1.5 2.0

V6

V8

Low 0.5

High 0.5

0.5 1.5

2.0 3.5

1.5 4.0 1.0 1.5 1.5 3.5 4.0

3.0 6.0 2.0 3.0 3.5 6.5 6.0

3.0 2.5 3.0 5.0

A VG 0.5 1.3 2.3 2.3 NA 1.5 2.0 2.3 4.8 NA 2.3 2.0 2.3 3.5

AVG 0.5 1.3 2.5 2.3 5.0

1.5 1.5

3.5 3.0

1.5 4.0

3.0 6.0

1.5 2.3 2.5 5.0 5.0 2.5 2.3 2.3 5.0

Low 0.5

High 0.5

1.0 2.0

2.0 4.0

2.0 5.0 1.5 1.5 2.0 4.0 5.0 2.0 2.0

3.0 10.0 2.0 3.0 4.0 6.5 10.0 4.0 3.0

1.5 4.0

3.0 6.0

AVG 0.5 1.5 3.0 2.5 7.5 1.8 2.3 3.0 5.3 7.5 3.0 2.5 2.3 5.0

DSL

15.0

35.0

25.0

15.0

35.0

25.0

NA

NA

NA

Conversion to Advanced Diesel Electrification/Accessory Techs

ADSL

7.0

13.0

10.0

7.0

13.0

10.0

22.0

38.0

30.0

Electric Power Steering (EPS) Improved Accessories Higher Voltage/Improved Alternator Transmission Techs

EPS IACC HVIA

1.0 0.5 0.0

3.0 1.5 0.5

2.0 1.0 0.3

1.0 0.5 0.0

3.0 1.5 0.5

2.0 1.0 0.3

1.0 0.5 0.0

3.0 1.5 0.5

2.0 1.0 0.3

Continuously Variable Transmission (CVT) 5-spd Auto. Trans. w/ Improved Internals 6-spd Auto. Trans. w/ Improved Internals

CVT

1.0 2.0 1.0

7.0 3.0 2.0

4.0 2.5 1.5

1.0 2.0 1.0

7.0 3.0 2.0

4.0 2.5 1.5

1.0 2.0 1.0

7.0 3.0 2.0

4.0 2.5 1.5

Conversion to Diesel

7-spd Auto. Trans. w/ Improved Internals 8-spd Auto. Trans. w/ Improved Internals 6/7/8-spd Auto. Trans. w/ Improved Internals 6/7-spd DCT from 4-spd A T 6/7-spd DCT from 6-spd A T Hybrid Techs

2.0 1.0

2.0 1.0

2.0 1.0

2.0 1.0

2.0 1.0

2.0 1.0

NAUTO DCT DCT

3.0 6.0 3.0

8.0 9.0 4.0

5.5 7.5 3.5

3.0 6.0 3.0

8.0 9.0 4.0

5.5 7.5 3.5

3.0 6.0 3.0

8.0 9.0 4.0

5.5 7.5 3.5

12V BAS Micro-Hybrid Integrated Starter Generator Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs

MHEV ISG PSHEV 2MHEV PHEV

2.0 29.0 24.0 25.0 NA

4.0 39.0 50.0 45.0 NA

3.0 34.0 37.0 35.0 NA

2.0 29.0 24.0 25.0 NA

4.0 39.0 50.0 45.0 NA

3.0 34.0 37.0 35.0 NA

2.0 29.0 24.0 25.0 NA

4.0 39.0 50.0 45.0 NA

3.0 34.0 37.0 35.0 NA

Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Aero Drag Reduction 10%

MR1 MR2 MR5 MR10 MR20 ROLL LDB AERO

3.5 7.0 13.0 3.0

0.3 1.4 3.3 6.5 12.0 2.0 1.0 1.5

3.5 7.0 13.0 3.0

0.3 1.4 3.3 6.5 12.0 2.0 1.0 1.5

3.5 7.0 13.0 3.0

0.3 1.4 3.3 6.5 12.0 2.0 1.0 1.5

0.3 1.4 3.0 6.0 11.0 1.0

1.0

1.0

2.0

0.3 1.4 3.0 6.0 11.0 1.0 1.0

1.0

2.0

0.3 1.4 3.0 6.0 11.0 1.0 1.0

1.0

2.0

NOTE: S om e of the beneits ( highlighted in green) e increm ar ental to those obtained with preceding tech nologies shown in the technology pathways described in Chapter 9 .

the Energy Independence and S ecurity A ct ( EIS A2 0) 0of 7 req uires periodic assessm ents by the NR C of autom ile ob vehicle fuel econom y technologies, including how such technologies m ight be used to m eet new fuel econom ndards. y sta F ollow- on NR C com m ittees will be responsible spondfor re ing to the EIS A m andates, including the periodic aluation ev of em erging technologies. Testing and Reporting of Vehicle Fuel Use F uel econom y is a m easure of how far a vehicletravel will with a gallon of fuel, whereas fuel consum ptionthe is am ount

of fuel consum ed in driving a given distance. A ugh lthoeach is sim ply the inverse of the other, fuel consum nptio is the fundam ental m etric by which to judge absolute imve-pro m ents in fuel eficiency, because what is im portant is gallons of fuel saved in the vehicle leet. The am ount of el fusaved directly relates not only to dollars saved on fuel purchases but also to q uantities of carbon diox ide em issions avoided. F uel econom y data cause consum ers to undervaluellsm a increases ( 1 - 4 m pg) in fuel econom y for vehicles the in 1 5 - 3 0 m pg range, where large decreases in fuel um cons ption can be realiz ed with sm all increases in fuel econom y. The percentage decrease in fuel consum ption is approx ately im

Technologies

Conversion to Diesel Conversion to Advanced Diesel Electrification/Accessory Techs Electric Power Steering (EPS) Improved Accessories Higher Voltage/Improved Alternator Transmission Techs Continuously Variable Transmission (CVT) 5-spd Auto. T rans. w/ Improved Internals 6-spd Auto. T rans. w/ Improved Internals 7-spd Auto. T rans. w/ Improved Internals 8-spd Auto. T rans. w/ Improved Internals 6/7/8-Speed Auto. T rans. with Improved Inter nals 6/7- spd DCT from 6-spd AT 6/7- spd DCT from 4-spd AT Hybrid Techs 12V BAS Micro-Hybrid Integrated Starter Gener ator Power Split Hybrid 2-Mode Hybrid Series PHEV 40 Vehicle T echs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance T ires Aero Drag Reduction 10% 70 70 15 150

EPS IACC HVIA CVT

137 -147 -14 450 1760 2708 5200 8000 37 77 217 520 1600 30 40

NAUT O DCT DCT MHEV ISG PSHEV 2MHEV PHEV MR1 MR2 MR5 MR10 MR20 ROLL AERO

133 170

2154 520

130 117 370

130 159 NA

130 NA

35

425 185 400

215 300

170

120 90 55

2632 520

160 195 490

160 205 NA

45 93 260 624 1700 40 50

550 2640 4062 7800 12000

425

133

35

35 35

160 NA

5 52.0

3 32.0

DSL ADSL

Abbreviation LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL SGDI TRBDS

High

Low

143 120 53 240 200 262 353 638 422 29 290 665 2926 4502 8645 13300 61 127 358 859 2475 53 68

95 80 35 160 133 174 235 425 281 19 193 500 2200 3385 6500 10000 41 85 239 572 1650 35 45

48 100 283 679 1600 30 40

585 2000 3120 5200 9600

137 -147 -14

133 170

243

70 70 15

425 185 400

215 300

263

58 121 339 815 1800 40 50

715 3000 4680 7800 14400

425

133

120 90 55

3491 683

53 111 311 747 1700 35 45

650 2500 3900 6500 12000

253 133 174 235 425 281 19 193

95 80 35

80 166 467 1 120 2550 53 68

865 3325 5187 8645 15960

380 200 262 353 638 422 29 290

143 120 53

4761 1025

68 142 399 958 1600 30 40

720 3200 4000 5200 13600

137 -147 -14

133 170

243

70 70 15

NA 3513

425 185 400

215 300

263

82 170 479 1 150 1900 40 50

880 4800 6000 7800 20400

425

133

120 90 55

NA 4293

NA 3903

2857 683

75 156 439 1054 1750 35 45

800 4000 5000 6500 17000

253 133 174 235 425 281 19 193

95 80 35

AVG

3174 683

V8 4 84 70 300 388.5 70 70 280 370 255 35 300 323 658

3590 780

4 42 35 145 NA 35 35 145 182 NA 35 145 156 430

AVG

Incremental Values - A preceding technology must be included V6 AVG w/1.5 AVG w/1.5 Low Low High AVG High RPE RPE 4 6 3 5 6 3 5 63 48 78 63 94.5 64 104 52.5 70 105 70 70 217.5 180 210 195 292.5 280 320 NA 340 400 370 555 357 420 70 52.5 105 70 70 70 70 70 52.5 105 217.5 180 220 200 300 260 300 273 290 310 300 450 350 390 NA 220 250 235 352.5 255 52.5 35 52.5 35 35 225 218 210 240 338 280 320 213 234 169 256 319 295 351 -144 205 31 525 790 645 46

2393 520

I4

NR C 2009 Costs

Com m ittee’s Estim ates of Technology in U Costs . S . D ollars ( 2 0 0 8 )

Spark Ignition Techs Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel T echs

TA BL E S . 2

1 13 234 659 1581 2625 53 68

1064 5320 6650 8645 22610

380 200 262 353 638 422 29 290

143 120 53

NA 5855

AVG w/1.5 RPE 6 126 105 450 582.75 105 105 420 555 382.5 52.5 450 485 986

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

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3

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

4

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

consum ers would pay for a fuel econom y technology. It is intended to relect long- run, substantially learned,industryaverage production costs that incorporate rates of proit and overhead ex penses. A critical issue is choice ofe th R P E m ark up factor, which represents the ratio of total cost of a com ponent, tak ing into account the full range ofstscoof doing business, to only the direct cost of the fully m anufactured com ponent. F or fully m anufactured com tsponen Recommendation: Because differences in the fuel consum p1 a reasonable average R P E purchased from a Tier 1 supplier, tion of vehicles relate directly to fuel savings, the labeling m ark up factor is 1 . 5 . F or in- house m anufactured po- com on new cars and light- duty truck s should include form in ation nents, a reasonable average R P E m ark up factor variable over on the gallons of fuel consum ed per 1 0 0 m iles ledtrave in m anufacturing costs is 2 . 0 . In addition to thes of cost m ateaddition to the already- supplied data on fuel econom y so that rials and labor and the ix ed costs of m anufacturing , the R P E consum ers can becom e fam iliar with fuel consumasption a factor for com ponents from Tier 1 suppliers include s proit, fundam ental m etric for calculating fuel savings. warranty, corporate overhead, and am ortiz ation ertain of c ix ed costs, such as research and developm ent. The P R E facF uel consum ption and fuel econom y are evaluated theby autom U . S . Environm ental P rotection A gency ( EP two A ) for tor thefor in- house m anufactured com ponents from obile m anufacturers includes the analogous com ponents the of driving cycles: the urban dynam om eter driving sched ule ( city Tier 1 m ark up for the m anufacturing operations, s addiplu cycle) and the highway dynam om eter driving schedule ( hightional ix ed costs for vehicle integration design and vehicle way cycle) . In the opinion of the com m ittee, hedules the sc tions, used to com pute CA F E should be m odiied so that clevehi installation, corporate overhead for assem bly opera additional product warranty costs, transportation, m ark ettest data better relect actual fuel consum ption. Ex cluding ing, dealer costs, and proits. R P E m ark up factors learly c som e driving conditions and accessory loads in dete rm ining vary depending on the com plex ity of the task ofegrating int CA F E discourages the introduction of certain techno logies a com ponent into a vehicle system , the ex tenteof changes th into the vehicle leet. The three additional schedules recently req uired to other com ponents, the novelty of the chnology, te adopted by the EP A for vehicle labeling purposes—on es and other factors. H owever, until em pirical data rived de via that capture the effects of higher speed and acceleration, air rigorous estim ation m ethods are available, the com ittee m conditioner use, and cold weather—represent a positive step prefers the use of average m ark up factors. forward, but further study is needed to assess to what degree A vailable cost estim ates are based on a varietysources: of the new test procedures can fully characteriz e changes in incom ponent cost estim ates obtained from suppliers, iscus-d use vehicle fuel consum ption. sions with ex perts at autom obile m anufacturerssuppliand ers, publicly available transaction prices, and comparisons Recommendation: The NH TS A and the EP A should review of the prices of sim ilar vehicles with and without a particular and revise fuel econom y test procedures so that the y better technology. H owever, there is a need for cost estim ates relect in- use vehicle operating conditions and alsoprovide based on a teardown of all the elem ents of a techno logy the proper incentives to m anufacturers to produce ehicles v and a detailed accounting of m aterials and capitalcosts that reduce fuel consum ption. and labor tim e for all fabrication and assem bly cesses. pro S uch teardown studies are costly and are not feasib le for Cost Estimation advanced technologies whose designs are not yet inaliz ed and/ or whose system integration im pacts are not fully yet L arge differences in technology cost estim ates can result m of e from differing assum ptions. These assum ptionsdeinclu understood. Estim ates based on the m ore rigorousthod teardown analysis would increase conidence in the accuracy whether costs are long- or short- term costs; whethe r learning of the costs of reducing fuel consum ption. by doing is included in the cost estim ate; whether the cost Technology cost estim ates are provided by the com ttee m i estim ate represents direct in- house m anufacturing ostscor for each fuel econom y technology discussed in thisreport. the cost of purchasing a com ponent from a supplier; and Ex cept as indicated, the cost estim ates represent he tprice which of the other changes in vehicle design that are req uired an autom obile m anufacturer would pay a supplier for a to m aintain vehicle q uality have been included in he tcost inished com ponent. Thus, on average, the R P E lier m ultip estim ate. Cost estim ates also depend greatly onum ass ed of 1 . 5 would apply to the direct, fully m anufacture d cost to production volum es. pay for In the com m ittee’s judgm ent, the concept of increm ntal e obtain the average additional price consum ers would a technology. A gain, ex cept where indicated otherwi se, the retail price eq uivalent ( R P E) is the m ost appropria te indicator of cost for the NH TS A ’s purposes because it best presents re the full, long- run econom ic costs of decreasing lfue con1 A Tier 1 supplier is one that contracts directly th wiautom obile m anusum ption. The R P E represents the average additional price facturers to supply technologies. eq ual to the percentage increase in fuel econom yr fo values less than 1 0 percent ( for ex am ple, a 9 . 1 percentage decrease in fuel consum ption eq uals a 1 0 percent increase fuelin econom y) , but the differences increase progressivel y: for ex am ple, a 3 3 . 3 percent decrease in fuel consum n eq uals ptio a 5 0 percent increase in fuel econom y.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

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cost estim ates provided are based on current condit ions and do not attem pt to estim ate econom ic conditionshence and predict prices 5 , 1 0 , or 1 5 years into the future.

5

consum ption and can also cause a slight increase inengine perform ance, which offers a potential opportunityorf engine downsiz ing. There are m any different im plem ations ent of V EM , and the costs and beneits depend on theciic spe engine architecture. F uel consum ption reduction can range Spark-Ignition Gasoline Engine Technologies from 1 percent with only intak e cam phasing, utto7abo perS park - ignition (S I) engines are ex pected to continue to be cent with a continuously variable valve lift and tim ing setup. the prim ary source of propulsion for light- duty veh icles in The increm ental R P E increase for valve- event mtion odula the U nited S tates over the tim e fram e of thist. repor There ranges from about $ 5 0 to $ 5 5 0 , with the am nding ount depe have been and continue to be signiicant im provem sent in on the im plem entation techniq ue and the engine architecture. reducing the fuel consum ption of S I engines in the areas of V ariable com pression ratio, cam less valve trains, nd a friction reduction, reduced pum ping losses through advanced hom ogeneous- charge com pression ignition were all vengi valve- event m odulation, therm al eficiency im provem nts, e careful consideration during the course of this study. Because cooled ex haust gas recirculation, and im proved over all of q uestionable beneits, m ajor im plem entation s, issue or engine architecture, including downsiz ing. A n imtantpor uncertain costs, it is uncertain whether any of these technoloattribute of im provem ents in S I engine technologies is that gies will have any signiicant m ark et penetrationthe in nex t they offer a m eans of reducing fuel consum ptionrelatively in 1 0 to 1 5 years. sm all, increm ental steps. This approach allowsmautoobile m anufacturers to create pack ages of technologiesatthcan Compression-Ignition Diesel Engine Technologies be tailored to m eet speciic cost and effectiveness targets, as opposed to developing diesel or full hybrid alternatives that L ight- duty com pression- ignition ( CI) engines ing operat offer a single large beneit, but at a signiicant cost increase. on diesel fuels have eficiency advantages over the m ore Because of the lex ibility offered by this approach,and given com m on S I gasoline engines. A lthough light- duty sel die the siz e of the S I engine- powered leet, the im plem ntatione vehicles are com m on in Europe, concerns over theility ab of S I engine technologies will continue to play aarge l role of such engines to m eet em ission standards for ogen nitr in reducing fuel consum ption. ox ides and particulates have slowed their introduction in the Of the technologies currently available, cylinder deU nited S tates. H owever, a joint effort betweenmauto obile activation is one of the m ore effective in reducingfuel m anufacturers and suppliers has resulted in new emssions i consum ption. This feature is m ost cost- effective enwh apcontrol technologies that enable a wide range of light- duty plied to six - cylinder ( V 6 ) and eight- cylinder overhead (V 8 ) CI engine vehicles to m eet federal and Californiame issions valve engines, and typically reduces fuel consum pti on by standards. The com m ittee found that replacing a72 m 0 0odel 4 to 1 0 percent at an increm ental R P E increase boutof a year S I gasoline power train with a base- level CI iesel d $ 5 5 0 . S toichiom etric direct injection typically ords a aff 1 .5 engine with an advanced 6 - speed dual- clutch automed at to 3 percent reduction in fuel consum ption at ancrem in enm anual transm ission ( D CT) and m ore eficientries accesso tal R P E increase of $ 2 3 0 to $ 4 8 0 , depending nder on cyli pack ages can reduce fuel consum ption by about 3 rcent 3 pe count and noise abatem ent req uirem ents. Turbochargi ng on an eq uivalent vehicle perform ance basis. Theim est ated and downsiz ing can also yield fuel consum ption redu cincrem ental R P E cost of conversion to the CI engine is tions. D ownsiz ing—reducing engine displacem ent ewhil about $ 3 , 6 0 0 for a four- cylinder engine and $for4 , 8 0 0 m aintaining vehicle perform ance—is an im portant ategy str a six - cylinder engine. A dvanced- level CI dieselines, eng applicable in com bination with technologies that in crease which are ex pected to reach m ark et in the 2 0 1 tim 1 - 2e 0 1 4 engine torq ue, such as turbocharging or superchargi ng. fram e, with D CT ( 7 / 8 speed) could reduce fuel m consu pD ownsiz ing sim ultaneously reduces throttling and iction fr tion by about an additional 1 3 percent for largerehicles v and losses because downsiz ed engines generally have smller a by about 7 percent for sm all vehicles. P art ofgain the from bearings and either fewer cylinders or sm aller cyli nder bore advanced- level CI diesel engines com es from downsiz ing. friction surfaces. R eductions in fuel consum ption an range c The estim ated increm ental R P E cost of the conversio n to the from 2 to 6 percent with turbocharging and down ing, siz depack age of advanced diesel technologies is about $, 46 0 0 for pending on m any details of im plem entation. This hnology tec sm all passenger cars and $ 5 , 9 0 0 for interm d ediate large an com bination is assum ed to be added after directection, inj passenger cars. and its fuel consum ption beneits are increm entalthose to A n im portant characteristic of CI diesel enginesthat is from direct injection. Based prim arily on an EPardown A te they provide reductions in fuel consum ption over th e entire study, the com m ittee’s estim ates of the costs urbochargfor t vehicle operating range, including city driving, highway ing and downsiz ing range from close to z ero addi onal ti cost, driving, hill clim bing, and towing. This attribute of CI diesel when converting from a V 6 to a four- cylinder ngine, ( I4 ) to e engines is an advantage when com pared with other chnolte alm ost $ 1 , 0 0 0 , when converting from a V gine. 8 to a V ogy 6 en options that in m ost cases provide fuel consumtion p V alve- event m odulation ( V EM ) can further reduce l beneits fue for only part of the vehicle operating range.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

6

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

The m ark et penetration of CI diesel engines will be tric vehicles ( i. e. , with driving range, trunk e, spac volum e, strongly inluenced by both the increm ental cost of CI diesel and acceleration com parable to those of vehicles po wered power trains above the cost of S I gasoline power tr ains and with internal- com bustion engines) depends on a batt ery cost by diesel and gasoline fuel prices. F urther, while technology break through that the com m ittee does not anticipate within im provem ents to CI diesel engines are ex pected each to rm arthe tim e horiz on considered in this study. H owever, it is clear k et in the 2 0 1 1 - 2 0 1 4 tim e fram e, technology m ents im that prove sm all, lim ited- range, but otherwise full-rm perfo ance to S I gasoline and hybrid engines will also enterhe t m ark et. battery electric vehicles will be m ark eted within hatt tim e Thus, com petition between these power train systemwills fram e. A lthough there has been signiicant progress in fuel continue with respect to reductions in fuel consum tion p and cell technology, it is the com m ittee’s opinion that fuel cell to cost. F or the period 2 0 1 4 - 2 0 2 0 , further l reducpotentia vehicles will not represent a signiicant fraction of on- road tions in fuel consum ption by CI diesel engines m be ayoffset light- duty vehicles within the nex t 1 5 years. by increases in fuel consum ption as a result of cha nges in engines and em issions system s req uired to m eet ntially pote Non-engine Technologies for Reducing Vehicle Fuel stricter em issions standards. Consumption There is a range of non- engine technologies with varying costs and im pacts. M any of these technologies are ontinuc Because of their potential to elim inate energy cons um pally being introduced to new vehicle m odels based no the tion when the vehicle is stopped, perm it brak ingergy en to tim ing of the product developm ent process. Coordina ting the be recovered, and allow m ore eficient use of the ternal in introduction of m any technologies with the productdevelcom bustion engine, hybrid technologies are one ofhet opm ent process is critical to m ax im iz ing im mpactiniand m ost active areas of research and deploym ent. The egree d m iz ing cost. R elatively m inor changes that do nvolve not i of hybridiz ation can vary from m inor stop- start stem sy s reengineering the vehicle or that req uire recertiication for with low increm ental costs and m odest reductionsfuel in fuel econom y, em issions, and/ or safety can be m im ented ple consum ption to com plete vehicle redesign and downsi z ing within a 2 - to 4 - year tim e fram e. These changes ld in-cou of the S I gasoline engine at a high increm ental cos t but with clude m inor reductions in m ass ( achieved by substit ution of signiicant reductions in fuel consum ption. F or the m ost m aterials) , im proving aerodynam ics, or switching low- to basic system s that reduce fuel consum ption by turni ng off rolling- resistance tires. M ore substantive changes, which rethe engine while the vehicle is at idle, the fuel consum ption q uire longer- term coordination with the productelopm dev ent beneit m ay be up to about 4 percent at an estim increated process because of the need for reengineering and integration m ental R P E increase of $ 6 7 0 to $ 1 , 1 0 sum 0 . The p- fuelwith conother subsystem s, could include resiz ing the ngine e and tion beneit of a full hybrid m ay be up to about 5 percent 0 transm ission or aggressively reducing vehicle m ass, such as at an estim ated increm ental R P E cost of $ 3 9, 0, 0 0 0toby $ changing the body structure. The tim e fram esubstanfor depending on vehicle siz e and speciic hybrid technology. A tive changes for a single m odel is approx im ately to 84 years. signiicant part of the im proved fuel consum ptionfull of hyTwo im portant technologies im pacting fuel consumon pti brid vehicles com es from the com plete vehicleign redes that are those for light- weighting and for im proving nsm tra iscan incorporate m odiications such as low- rolling-sistance re sions. L ight- weighting has signiicant potential bec ause tires, im proved aerodynam ics, and the use of sm r, malleore vehicles can be m ade very light with ex otic m ateria ls, albeit eficient S I engines. at potentially high cost. The increm ental cost toeduce r a In the nex t 1 0 to 1 5 years, im provem entsvehicles in hybrid pound of m ass from the vehicle tends to increasethe as total will occur prim arily as a result of reduced costsorf hybrid am ount of reduced m ass increases, leading to dim shing ini power train com ponents and im provem ents in battery perforreturns. A bout 1 0 percent of vehicle m ass can imbe inated el m ance such as higher power per m ass and volum reased e, inc at a cost of roughly $ 8 0 0 to $ 1 , 6 0 0 and can a fuel provide num ber of lifetim e charges, and wider allowable state- of- consum ption beneit of about 6 to 7 percent. R geducin m ass charge ranges. D uring the past decade, signiicantdvances a m uch beyond 1 0 percent req uires attention to body truc-s have been m ade in lithium - ion battery technology. henW ture design, such as considering an alum inum - intens ive car, the cost and safety issues associated with them are resolved, which increases the cost per pound. A 1 0 percent duction re lithium - ion batteries will replace nick el- m etalridehyd batin m ass over the nex t 5 to 1 0 years appears to ithin be reach w teries in hybrid electric vehicles and plug- in hybrid electric for the typical autom obile. vehicles. A num ber of different lithium - ion chem ries areist Transm ission technologies have im proved signiicantl y being studied, and it is not yet clear which ones will prove and, lik e other vehicle technologies, show a simr trend ila m ost beneicial. Given the high level of activity in lithium of dim inishing returns. P lanetary- based autom ransm atic t ision battery developm ent, plug- in hybrid electrichicles ve will sions can have 5 , 6 , 7 , and 8 speeds, but with em incr ental be com m ercially viable and will soon enter at least lim ited costs increasing faster than reductions in fuel consum ption. production. The practicality of full- perform ancettery ba elecD CTs are in production by som e autom obile m anufactu rers, Hybrid Vehicle Technologies

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

SU MMAR Y

and new production capacity for this transm issionype t has been announced. It is ex pected that the predom inant trend in transm ission design is conversion to 6 - to 8 - speed planetarybased autom atics and to D CTs, with continuouslyiable var transm issions rem aining a niche application. Given the close link age between the effects of fuel- consum ption-ucing red engine technologies and transm ission technologies,the present study has for the m ost part considered the com bined effects of engines and transm ission com binations ther ra than potential separate effects. A ccessories are also being introduced to new vehicl es to reduce the power load on the engine. H igher- efic iency air conditioning system s are available that m oretim op ally m atch cooling with occupant com fort. Electric and lectric/ e hydraulic power steering also reduces the load on an engine by dem anding power only when the operator turns the wheel. A n im portant m otivating factor affecting the introd uction of these accessories is whether or not their im pactis m easured during the EP A driving cycles used to estim e fuel at consum ption.

7

Com parisons of F S S m odeling and P D A estim ation sup ported by lum ped param eter m odeling have shownthe that two m ethods produce sim ilar results when sim ilar sumas ptions are used. In som e instances, com paring the times ates m ade by the two m ethods has enhanced the overalllidva ity of estim ated fuel consum ption im pacts by uncove ring inadvertent errors in one or the other m ethod. In the com m ittee’s judgm ent both m ethods are valuable, ally especi when used together, with one providing a check onhet other. H owever, m ore work needs to be done to establish e accuth racy of both m ethods relative to actual m otor vehic les. The D epartm ent of Transportation’s V olpe National Transportation S ystem s Center has developed a m for odel the NH TS A to estim ate how m anufacturers canwith com ply fuel econom y regulations by applying additional fue l savings technologies to the vehicles they plan to produce. The m odel em ploys a P D A algorithm that includes es of estim at the effects of interactions am ong technologies appl ied. The validity of the V olpe m odel could be im proved kbying ta into account m ain and interaction effects producedby the F S S m ethodology described in Chapter 8 of this rt. repo In particular, m odeling work done for the com m ittee an by Modeling Reductions in Fuel Consumption Obtained from outside consulting irm has dem onstrated a practical m ethod Vehicle Technologies for using data generated by F S S m odels to accuratel y assess The two prim ary m ethods for m odeling technologies’the fuel consum ption potentials of com binationsdoz of ens reduction of vehicle fuel consum ption are full syst em sim ula- of technologies on thousands of vehicle conigurations. A tion ( F S S ) and partial discrete approx im ation . F( PS D S A is design) of- ex perim ents statistical analysis of F odel S Sruns m the state- of- the- art m ethod because it is basedintegration on dem onstrated that m ain effects and irst- order action inter of the eq uations of m otion for the vehicle carried out over effects alone could predict F S S m odel outputs an with R2 the speed- tim e representation of the appropriate iving dr or of 0 . 9 9 . U sing such an approach could appropriately com test cycle. D one well, F S S can provide an accurate assessbine the strengths of both the F S S and the P D Alingm ode m ent ( within + / –5 percent or less) of the im n pacts fuel o m ethods. H owever, in the following section, themcom ittee consum ption of im plem enting one or m ore technologie s. recom m ends an alternate approach that uses F S etter S to b The validity of F S S m odeling depends on the accurac y of assess the contributory effects of the technologies applied representations of system com ponents. Ex pert judgm nt is e in the reduction of energy losses and to better couple the also req uired at m any points and is critical to obt aining acm odeling of fuel econom y technologies to the testin g of such curate results. A nother m odeling approach, the Pm Dethod, A technologies on production vehicles. relies on other sources of data for estim ates of th e im pacts of fuel econom y technologies and relies on m athem ical at Application of Multiple Vehicle Technologies to Vehicle sum m ation or m ultiplication m ethods to aggregate e effects th Classes of m ultiple technologies. S ynergies am ong technolog ies can be represented using engineering judgm ent andum l ped F igures 9 . 1 to 9 . 5 in Chapter 9 of this report lay the disp 2 or can be synthesiz ed from param eter m odels F S S results.technology pathways developed by the com m ittee eight for U nlik e F S S , the P D A m ethod cannot be used te to classes genera of vehicles and the aggregated fuel consum tion p benestim ates of the im pacts of individual technologies on fuel eits and costs for the S I engine, CI engine, and brid hy power consum ption. Thus, the P D A m ethod by itself, F Sunlik S , etrain pathways. The results of the com m ittee’s ysis anal are is not suitable for estim ating the fuel consum ption im pacts that, for the interm ediate car, large car, and unib ody standard of technologies that have not already been tested in actual truck classes, the average reduction in fuel consum ption for vehicles or whose fuel consum ption beneits have notbeen the S I engine path is about 2 9 percent at a costapprox of iestim ated by m eans of F S S . m ately $ 2 , 2 0 0 ; the average reduction for the ineCI path eng is about 3 7 percent at a cost of approx im ately0$05; , and 9 2 L um ped param eter m odels are sim pliied analytical the average reduction for the hybrid power train path is about ools for estim t ating vehicle energy use based on a sm all set of energy alance b eq uations and 4 4 percent at a cost of $ 6 , 0 0 0 . These values proxareimap ate em pirical relationships. W ith a few k ey vehicle ampareters, these m ethods and are provided here as rough estim ates that canebused for can ex plicitly account for the sources of energy loss and the tractive force q ualitative com parison of S I engine- related technol ogies and req uired to m ove the vehicle.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

8

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

other candidates for the reduction of vehicle fuel consum ption, such as light- duty diesel or hybrid vehicles. Improvements to Modeling of Multiple Fuel Economy Technologies

vehicles. Com bining the results of such testing wit h F S S m odeling, and thereby m ak ing all sim ulationes variabl and subsystem m aps transparent to all interested partie s, would allow the best opportunity to deine a technical baseline against which potential im provem ents could be analy z ed m ore accurately and openly than is the case with th e current m ethods em ployed. The steps in the recom m ended process would be as follows:

M any vehicle and power train technologies that imove pr fuel consum ption are currently in or entering produ ction or are in advanced stages of developm ent in EuropeanroA sian m ark ets where high consum er fuel prices have m om ade-c m ercializ ation of the technologies cost- effective. D epending 1 . D evelop a set of baseline vehicle classes from which a on the intended vehicle use or current state of energy- loss characteristic vehicle can be chosen to represent each reduction, the application of increm ental technolog ies will class. The vehicle m ay be either real or theoretica l produce varying levels of im provem ent in fuel consu m pand will possess the average attributes of that class as tion. D ata m ade available to the com m ittee from autom e obil determ ined by sales- weighted averages. m anufacturers, Tier 1 suppliers, and other publishe d studies 2 . Identify technologies with a potential to reduc e fuel also suggest a very wide range in estim ated incremntale consum ption. cost. A s noted above in this S um m ary, estimedates on bas 3 . D eterm ine the applicability of each technology to the teardown cost analysis, currently being utiliz ed bythe EP A various vehicle classes. in its analysis of standards for regulating light- duty- vehicle 4 . Estim ate each technology’s prelim inary im n fuel pact o greenhouse gas em issions, should be ex panded for developconsum ption and cost. ing cost im pact analyses. The com m ittee notes,ver, howe that 5 . D eterm ine the optim um im plem entation seq uenc cost estim ates are always m ore uncertain than estim ates of ( technology pathway) based on cost- effectiveness dan fuel consum ption. engineering considerations. F S S m odeling that is based on em pirically derived ower p 6 . D ocum ent the cost- effectiveness and engineering train and vehicle perform ance and on fuel consum on pti judgm ent assum ptions used in step 5 and m ak e this data m aps offers what the com m ittee believes isbest the inform ation part of a widely accessible database. available m ethod to fully account for system energy losses 7 . U tiliz e m odeling software ( F S S ) to ough progress thr and to analyz e potential im provem ents in fuel consu m ption each technology pathway for each vehicle class to achievable by technologies as they are introduced into the obtain the inal increm ental effects of adding each m ark et. A nalyses conducted for the com m ittee hatshow the t technology. effects of interactions between differing types of technologies for reducing energy loss can and often do vary greatly If such a process were adopted as part of a regulatory rulefrom vehicle to vehicle. m ak ing procedure, it could be com pleted on 3 -ycles year c to allow regulatory agencies suficient lead tim e to integrate Recommendation: The com m ittee proposes a m ethod the results into future proposed and enacted rules. whereby F S S analyses are used on class- characteriz ng ve-i hicles, so that synergies and effectiveness in im em pl enting CONCLUDING COMMENTS m ultiple fuel econom y technologies can be evaluated with what should be greater accuracy. This proposed m eth od would A signiicant num ber of approaches are currently ilava determ ine a characteristic vehicle that would be de ined as a able to reduce the fuel consum ption of light- dutyehicles, v reasonable average representative of a class of vehicles. This ranging from relatively m inor changes to lubricants and tires representative vehicle, whether real or theoretical, would to large changes in propulsion system s and vehicle platform s. undergo sufficient F S S , com bined with ex perim y entall Technologies such as all- electric propulsion systems have determ ined and vehicle- class- speciic system mg,appin to also dem onstrated the potential to reduce fuel cons um ption, allow a reasonable understanding of the contributory effects although further developm ent is req uired to determ ne the i of the technologies applied to reduce vehicle energy losses. degree of im provem ent, cost- effectiveness, andbility. dura D ata developed under the U nited S tates Council Aforutom o- The developm ent and deploym ent of vehicles that sum con e tive R esearch ( U S CA R ) Benchm ark ing Consortium d less shoul fuel will be inluenced not only by technological factors be considered as a source for such analysis and potentially but also by econom ic and policy factors whose ex am ination ex panded. U nder the U S CA R program , actual n productio is beyond the scope of this study. F uture NR C comttees m i vehicles are subjected to a battery of vehicle, engine, and will be responsible for periodic assessm ents of the cost and transm ission tests in suficient detail to understan d how each beneits of technologies that reduce vehicle fuel consum pcandidate technology is applied and how they contribute to tion, including how such technologies m ight be used to m eet the overall perform ance and fuel consum ption ofhtligduty new fuel econom y standards.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

1 Introduction

The im pacts of fuel consum ption by light- duty vehic les fuel econom y/ greenhouse gas em ission standard ightfor l are profound, inluencing econom ic prosperity, natio nal duty vehicles that m irrors the stringency of the Ca lifornia security, and Earth’s environm ent. Increasing ener gy efiem issions standard. F inaliz ed on A pril 1 , 2 rule 0 1re0 , the ciency has been a continuing and central objective for autoq uires that leet- averaged fuel econom y reach an ivalent eq u m obile m anufacturers and regulators pursuing object ives that of 3 5 . 4 m pg by m odel year 2 0 1 6 . range from reducing vehicle operating costs and imroving p The signiicant downturn in the U nited S tates and rld wo perform ance to reducing dependence on petroleum and econom ies that occurred during the course of thistudy s has lim iting greenhouse gas em issions. Given heightened conhad substantial negative im pacts on the global auto m obile cerns about the dangers of global clim ate change,het needs industry. M ost m anufacturers have ex perienced ed reduc for energy security, and the volatility of world oil prices, sales and suffered losses. The autom obile industry is capital attention has again been focused on reducing the fuel conintensive and has a very steep curve on proits around the sum ption of light- duty vehicles. A wide arraychnologies of te break - even point: a sm all increase in sales beyond the break and approaches ex ist for reducing fuel consum ption. These even point can results in large proits, while a sm lladecrease im provem ents range from relatively m inor changes th wi can result in large losses. Consum er spending decre ased low costs and sm all fuel consum ption beneits—such s use a m ark edly due to lack of conidence in the econom well y as of new lubricants and tires—to large changes in propulsion as dificulties in the credit m ark ets that typically inance system s and vehicle platform s that have high costs and large a large portion of vehicle purchases. The U . S . m et for ark fuel consum ption beneits. light- duty vehicles decreased from about 1 6 m vehicles illion annually for the last few years to about 1 0 m illion in 2 0 0 9 . The overall econom ic conditions resulted in Chrysle r and CURRENT POLICY CONTEXT AND MOTIVATION GM deciding to ile for Chapter 1 9 bank ruptcy and F ord in The rapid rise in gasoline and diesel fuel prices ex periex cessively leveraging its assets. GM and Chrysler have reenced during 2 0 0 6 - 2 0 0 8 and growing recognition of climcently ate-ex ited bank ruptcy, and the U . S . governm ent is now the change issues have helped m ak e vehicle fuel economan y m ajor shareholder of GM . F iat A utom obiles has e a 2becom 0 im portant policy issue once again. These conditions have percent shareholder in Chrysler, with the potentialto ex pand m otivated several recent legislative and regulatoryinitiaits ownership to 3 5 percent, and the newly form oluntary ed V tives. The irst m ajor initiative was the m andate r increased fo Em ployee Beneiciary A ssociation has a 5 5 percent ak e.st CA F E standards under the Energy Independence and These econom ic conditions will im pact autom otive m co S ecurity A ct of 2 0 0 7 . This legislation req e National uires th panies’ and suppliers’ ability to fund in a tim ely m anner the H ighway Trafic S afety A dm inistration ( NH TSseA ) to R rai & D necessary for fuel econom y im provem ents and the capvehicle fuel econom y standards, starting with m odel year ital ex penditures req uired. A lthough addressingim the pact 2 0 1 1 , until they achieve a com bined averageonom fuel ec y of such conditions on the adoption of vehicle fuel econom y of at least 3 5 m iles per gallon ( m pg) for m r odel 2 0 yea 2 0 . technologies is not within the purview of this com m ittee, The policy landscape has also been signiicantly altered by these conditions do provide an im portant contex tr fo this separate S uprem e Court decisions related to the ulation reg of study. M anufacturers will choose fuel econom y techn olocarbon diox ide as an air pollutant and the California greengies based on what they think will be m ost effectiv e and best house gas vehicle standards. These decisions helped spur received by consum ers. Custom ers also will haveentral ac the Obam a adm inistration to direct the U . S . m Environ ental role in what technologies are actually chosen and will m ak e P rotection A gency ( EP A ) and the NH TS A joint to developthose a choices based partly on initial and operating costs. 9

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

10

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

S ubsidies and other incentives also can signiicantl y im pact and suppliers worldwide are im proving their capabili ties the m ark et acceptance rate of technologies that red uce fuel in hybrid- electric technologies. F urther, policycentives in consum ption. F inally, adoption of these technologie s m ust m ay help favor one technology over another in indiv idual play out in a som etim es unpredictable m ark etplace and pol-countries. icy setting, with changing standards for em issions and fuel econom y, governm ent incentives, consum er preferences, and STATEMENT OF TASK other events im pacting their adoption. Thus, themco m ittee ack nowledges that technologies downplayed here m play ay The NH TS A has a m andate to k eep up- to- date on the a bigger role than anticipated, or that technologies covered potential for technological im provem ents as it ms into ove in this report m ay never em erge in the m ark etplace. planned vehicular regulatory activities. It was as part of its The tim ing for introducing new fuel consum ptionh-tec technology assessm ent that the NH TS A ask ed onal the Nati nologies m ay have a large influence on cost and ris k . A cadem ies to update the 2 0 0 2 National R esearch cil Coun The individual vehicle m odels produced by autom obil e report Effectiveness and Imp act o f Co rp o rate Averag e F u el m anufacturers pass through a product cycle that inc ludes Eco no my ( CAF E) Standards ( NR C, 2 0 0 2 ) and add to its introduction, m inor refreshm ents of design and ures, feat assessm ent other technologies that have em ergedce sinthat and then full changes in body designs and power trains. report was prepared. The statem ent of task ( seeendix A pp B) To reduce costs and q uality concerns, changes to re duce directed the Com m ittee on the A ssessm ent of Technol ogies fuel consum ption norm ally are tim ed for im plem ion entatfor Im proving L ight- D uty V ehicle F uel Econom tim yate to es in accordance with this process. F urther, new techn ologies the eficacy, tim ing, cost, and applicability ofhnologies tec are often applied irst in lower- volum e, higher- end vehicles that m ight be used over the nex t 1 5 years. The of list techbecause such vehicles are better able to absorb the higher nologies includes diesel and hybrid electric power trains, costs, and their lower volum es reduce ex posure isk to r . In which were not considered in the 2 0 0 2 NR C report. eight W general, 2 to 3 years is considered the q uick m est eti fram e and power reductions also were to be included, but not for bringing a new vehicle m odel to m ark et or for odifym siz e or power- to- weight ratio reductions. U pdating the fuel ing an ex isting m odel. S igniicant carryover technol ogy and econom y- cost relationships for various technologies and difengineering from other m odels or previous vehicleodels m ferent vehicle siz e classes as represented in Chapter 3 of the are usually req uired to launch a new m odel this qck uily, 2 0 0 2 report was central to the study req uest. and the ability to signiicantly inluence fuel consum ption The current study focuses on technology and does not is thus sm aller. M ore substantial changes to a ml occur ode consider CA F E issues related to safety, econom fects ic efon over longer periods of tim e. Newly styled, engineer ed, and industry, or the structure of fuel econom y standard s; those redesigned vehicles can tak e from 4 to 8 yearsroduce, to p issues were addressed in the 2 0 0 2 report. The new tudy s each with an increasing am ount of new content. F her, urt the look s at lowering fuel consum ption by reducing powe r engine developm ent process often follows a path sep arate req uirem ents through such m easures as reduced vehic le from that for other parts of a vehicle. Engines hav e longer weight, lower tire rolling resistance, or im proved vehiproduct lives, req uire greater capital investm ent, and are not cle aerodynam ics and accessories; by reducing the am ount of as critical to the consum er in differentiating one vehicle from fuel needed to produce the req uired power throughm i proved another as are other aspects of a car. The norm alower p train engine and transm ission technologies; by recovering som e developm ent process evolves over closer to a 1 5 - year cycle, of the ex haust therm al energy with turbochargersdanother although reinem ents and new technologies will be im pletechnologies; and by im proving engine perform ance nd a m ented throughout this period. It should be notedhatt there recovering energy through regenerative brak ing in yhbrid are signiicant differences am ong m anufacturers in their- ap vehicles. A dditionally, the com m ittee was charged ith asw proaches to introducing new m odels and, due to regu latory sessing how ongoing changes to m anufacturers’ refre sh and and m ark et pressures, product cycles have tendedbecom to e redesign cycles for vehicle m odels affect the incorporation of shorter over tim e. new fuel econom y technologies. The current study ilds bu on A lthough it is not a focus of this study, the globa l setinform ation presented in the com m ittee’s previously released ting for the adoption of these fuel econom y technol ogies is interim report ( NR C, 2 0 0 8 ) . critical. The two m ain types of internal com bustion engines, gasoline spark - ignition ( S I) and diesel com pression - ignition CONTENTS OF THIS REPORT ( CI) , are not necessarily fully interchangeable. ude Cr oil ( which varies in com position) contains heavier frac tions that The com m ittee organiz ed its inal report according o t go into diesel production and lighter fractions that go into broad topics related to the categories of technologies im porgasoline. A large consum er of diesel, Europe divert s the retant for reducing fuel consum ption, the costs and ssues i assom aining gasoline fraction to the U nited S tateslsewhere. or e ciated with estim ating the costs and price im pacts of these China is now using m ostly gasoline, and so there is m ore technologies, and approaches to estim ating the fuel condiesel available globally. A nd autom obile m anufactu rers sum ption beneits possible with com binations of thes e tech-

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

11

INTR ODU CTION

nologies. Chapter 2 describes fundam entals of deter m ining vehicle fuel consum ption, tests for regulating fuel econom y, and basic energy balance concepts, and it discusseswhy this report presents prim arily fuel consum ption data.apter Ch 3 describes cost estim ation for vehicle technologies, including m ethods for estim ating the costs of a new technolog y and issues related to translating those costs into im pa cts on the retail price of a vehicle. Chapters 4 through 7 des cribe technologies for im proving fuel consum ption in sparknition - ig gasoline engines ( Chapter 4 ) , com pression- ignition diesel engines ( Chapter 5 ) , and hybrid- electric vehicles Chapter ( 6 ). Chapter 7 covers non- engine technologies for reduci ng lightduty vehicle fuel consum ption. Chapter 8 providesbasic a overview of and discusses the attributes of two different approaches for estim ating fuel consum ption beneits—th e discrete approx im ation and the full- system sim m ulation odeling

approaches. Chapter 9 provides an estim ate of the ostsc and the fuel consum ption beneits of m ultiple technologi es for an array of vehicle classes. The appendix es provide in form ation related to conducting the study ( A ppendix es A gh throu C) , a list of the acronym s used in the report ( A ppendix D ) , and additional inform ation supplem enting the individual chapters ( A ppendix es E through K ) .

REFERENCES NR C ( National R esearch Council) . 2 0 0 2 . Effectivenes s and Im pact of Corporate A verage F uel Econom y ( CA F E) S tandards. ngton,WD ashi . C. : National A cadem y P ress. NR C. 2 0 0 8 . Interim R eport of the Com m ssessm ittee onent theofATechnologies for Im proving L ight- D uty V ehicle F om uel Econ y. W ashington, D . C. : The National A cadem ies P ress.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 Fundamentals of Fuel Consumption

INTRODUCTION

ever, by the late 1 9 5 0 s, fuel econom y had becom portant, e im leading to the irst large wave of foreign im ports. In the wak e This chapter provides an overview of the various elem ents of the 1 9 7 3 oil crisis, the issue of energy securit y arose, and that determ ine fuel consum ption in a light- dutyicle veh Congress passed the Energy P olicy and ConservationA ct ( L D V ) . The prim ary concern here is with power s thattrain of 1 9 7 5 as a m eans of reducing the country’s depend ence convert hydrocarbon fuel into m echanical energy usi ng on im ported oil. The act established the Corporate A verage an internal com bustion engine and which propel a ve hicle F uel Econom y ( CA F E) program , which req uired ile autom ob though a drive train that m ay be a com bination of m a echanim anufacturers to increase the average fuel economofypascal transm ission and electrical m achines ( hybrid opulsion) pr . senger cars sold in the U nited S tates in 1 9 9 standard 0 to a of A brief overview is given here of spark - ignitionI)( Sand 2 7 . 5 m iles per gallon ( m pg) and allowed the partm U . Sent. D e com pression- ignition ( CI) engines as well as hybrid s that of Transportation ( D OT) to set appropriate standard s for com bine electric drive with an internal com bustion engine; light truck s. The standards are adm inistered in D byOT the these topics are discussed in detail in Chapters 4 through 6 . National H ighway Trafic S afety A dm inistration (ANH) TS The am ount of fuel consum ed depends on the engine, the on the basis of U . S . Environm ental P rotectionyA ( EP genc A ) type of fuel used, and the eficiency with which the output city- highway dynam om eter test procedures. of the engine is transm itted to the wheels. Thisel fuenergy is used to overcom e ( 1 ) rolling resistance prim ue arily to lex d FUEL CONSUMPTION AND FUEL ECONOMY ing of the tires, ( 2 ) aerodynam ic drag as the le vehic m otion is resisted by air, and ( 3 ) inertia and hill- clim ng forces bi that Before proceeding, it is necessary to deine the term fu s el resist vehicle acceleration, as well as engine and drive line eco no my and fu el co nsu mp; tio these n two term s are widely losses. A lthough m odeling is discussed in detail later in chapused, but very often interchangeably and incorrectly, which ters ( Chapters 8 and 9 ) , a sim ple m odel to describe tractive can generate confusion and incorrect interpretations: energy req uirem ents and vehicle energy losses isven gi here as well to understand fuel consum ption fundam entals . A lso • F u el eco nois my a m easure of how far a vehicle will included is a brief discussion of custom er ex pectat ions, since travel with a gallon of fuel; it is ex pressed in mles iper perform ance, utility, and com fort as well as fuel onsum c ption gallon. This is a popular m easure used for a longimt e are prim ary objectives in designing a vehicle. by consum ers in the U nited S tates; it is usedby also F uel eficiency is a historical goal of autom otive engineervehicle m anufacturers and regulators, m ostly to -com ing. A s early as 1 9 1 8 , General M otors Com otive pany autom m unicate with the public. A s a m etric, fuel econom y pioneer Charles K ettering was predicting the dem of isethe actually m easures distance traveled per unit of fue l. internal com bustion engine within 5 years becausef its o • F u el co nsu mp is the tio inverse n of fuel econom y. It is wasteful use of fuel energy: “[ T] he good L ord has olerated t the am ount of fuel consum ed in driving a given disthis foolishness of throwing away 9 0 percent of the energy tance. It is m easured in the U nited S tates inns gallo per in the fuel long enough” ( K ettering, 1 9 1 8 ) .eed, A nd in ind 1 0 0 m iles, and in liters per 1 0 0 k ilom pe eters in Euro the 1 9 2 0 s through the 1 9 5 0 s peak eficiencies rom went 1 0f and elsewhere throughout the world. F uel consum nptio percent to as m uch as 4 0 percent, with im provem in fuels, ents is a fundam ental engineering m easure that is direct ly com bustion system design, friction reduction, and orem prerelated to fuel consum ed per 1 0 0 m iles and is l usefu cise m anufacturing processes. Engines becam e m owerore p because it can be em ployed as a direct m easure of ful, and vehicles becam e heavier, bigger, and faste r. H owvolum etric fuel savings. It is actually fuel consum ption 12

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

13

F U NDAMENTALS OF F U EL CONSU MP TION

that is used in the CA F E standard to calculate the leet 5 0 gallons, as com pared to the 5 0 0 gallons in from going average fuel econom y ( the sales weighted average) or f 1 0 - 2 0 m pg. A ppendix E discusses further simof plication the city and highway cycles. The details of this calcuthe relationship between fuel consum ption and fuel econom y lation are shown in A ppendix E. F uel consum ption isfor various fuel econom y values, and particularlyorf those also the appropriate m etric for determ ining the rly yea greater than 4 0 m pg. fuel savings if one goes from a vehicle with a give n fuel F igure 2 . 2 illustrates the relationship betweenpercentthe consum ption to one with a lower fuel consum ption. age of fuel consum ption decrease and that of fuelconom e y increase. F igures 2 . 1 and 2 . 2 illustrate that m the ounta of fuel Because fuel econom y and fuel consum ption are recip rosaved by converting to a m ore econom ical vehiclepends de cal, each of the two m etrics can be com puted intraightas on where one is on the curve. forward m anner if the other is k nown. In m athem al atic Because of the nonlinear relationship in F igure 2 , . con1 term s, if fuel econom y is X and fuel consum Y ption , their is sum ers can have dificulty using fuel econom y as easure am relationship is ex pressed by X Y = 1 . This relations hip is not of fuel eficiency in judging the beneits of replacing the linear, as illustrated by F igure 2 . 1 , in whichconsum fuel ption m ost ineficient vehicles ( L arrick and S oll, L 2 0arrick 0 8 ). is shown in units of gallons per 1 0 0 m iles, and l econom fue y and S oll further conducted three ex perim ents tot whether tes is shown in units of m iles per gallon. A lso shown in the igure people reason in a linear but incorrect m anner abou t fuel is the decreasing inluence on fuel savings that accom panies econom y. These ex perim ental studies dem onstrated sys- a increasing the fuel econom y of high- m pg vehicles. ach E bar tem ic m isunderstanding of fuel econom y as a m of easure represents an increase of fuel econom y by 1 0 0 nt perce or the fuel eficiency. U sing linear reasoning about fuelconom e y corresponding decrease in fuel consum ption by 5 0rcent. pe leads people to undervalue sm all im provem entsm( 1pg) - 4 in The data on the graph show the resulting decrease in fuel lower- fuel- econom y ( 1 5 - 3 0 m pg range) vehicles there where consum ption per 1 0 0 m iles and the total fuelinsaved driving are large decreases in fuel consum ption ( L arrickd Sanoll, 1 0 , 0 0 0 m iles. The dram atic decrease in the f increasim pact o 2 0 0 8 ) in this range, as shown in F igure 2 . r1( .2 F0 ische 0 9 ) ing m iles per gallon by 1 0 0 percent for a high-vehicle m pg further discusses the potential beneits of utiliz ing a m etric is m ost visible in the case of increasing the m iles per gallon based on fuel consum ption as a m eans to aid consum rs in e rating from 4 0 m pg to 8 0 m pg, where the total fuel saved in calculating fuel and cost savings resulting from im proved driving 1 0 , 0 0 0 m iles is only 1 2 5 gallons,to com 5 0 0pared vehicle fuel eficiency. gallons for a change from 1 0 m pg to 2 0 m pg. e, itL ik ewisThroughout this report, fuel consum ption is used as is instructive to com pare the sam e absolute value f fuel o the m etric owing to its fundam ental characteristic and its econom y changes—for ex am ple, 1 0 - 2 0 m pg and g. 4 0 suitability - 5 0 m for p judging fuel savings by consum ers.In cases The 4 0 - 5 0 m pg fuel saved in driving 1 0 , 0 0uld0 bem ileswhere wo the com m ittee has used fuel econom y data the from

25

10 1000

Fuel Consumption Gallons/100 miles

20

50% decrease in FC and 100% increase in FE

15

10

5

Decrease in FC, gallons/100 miles

500

5

2.5

Gallons saved for 10,000 miles

250

125

1.25 0 0

10

20

30 40 50 Fuel Economy , mpg

60

70

80

90

F IGU R E 2 . 1 R elationship between fuel consum C) ption and fuel ( F econom y ( F E) illustrating the decreasin g reward of im proving fuel econom y ( m iles per gallon [ m pg] ) for high- gallon m ile-vehicles. perThe width of each rectangle represents a 5 0 percent decrease in F C or a 1 0 0 percent increase in F E. The num ber the within rectangle is the decrease in F C per 1 0 0 mand iles, the num ber to the right of the rectangle is the total fuel saved over 1 0 , 0 0 0 by m the ilescorresponding 5 0 percent decrease in F C.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

14

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

50.0

50.0 41.2

FC Decrease %

40.0 33.3 28.6

30.0 23.1

20.0

16.7 9.1

10.0 0.0 0

10

20

30

40

50

60

70

80

90

100

FE Increase,%

F IGU R E 2 . 2 P ercent decrease in fuel consum ) ption as a function ( F C of percent increase in fuel econom (yF E) , illustrating the decreasing beneit of im proving the fuel econom y of vehiclesthwi an already high fuel econom y.

literature, the data were converted to fuel consum tion, p usD iesel engines—which operate on “diesel” fuels, nam ed ing the curve of either F igure 2 . 1 or 2 . 2 foreschang in fuel after inventor R udolf D iesel—rely on com pression ating he econom y. Because of this, the com m ittee recom that m endsof the air/ fuel m ix ture to achieve ignition. This eport r uses the fuel econom y inform ation stick er on new cars d truck an s the generic term com pression- ignition engines to ferreto should include fuel consum ption data in addition to the fuel diesel engines. econom y data so that consum ers can be fam iliar this with The distinction between these two types of engines is fundam ental m etric since fuel consum ption differenc e bechanging with the developm ent of engines having som e of tween two vehicles relates directly to fuel savings. The fuel the characteristics of both the Otto and the diesel cycles. consum ption m etric is also m ore directly related overall to A lthough technologies to im plem ent hom ogeneous ge char em issions of carbon diox ide than is the fuel econom y m etric. com pression ignition ( H CCI) will m ost lik elyavailnot be able until beyond the tim e horiz on of this report, the use of a hom ogeneous m ix ture in a diesel cycle conferscharthe ENGINES acteristic of the Otto cycle. L ik ewise the present widespread M otor vehicles have been powered by gasoline, diese l, use of direct injection in gasoline engines confers som e of steam , gas turbine, and S tirling engines as well byaselectric the characteristics of the diesel cycle. Both types of engines and hydraulic m otors. This discussion of engines lim is ited are m oving in a direction to utiliz e the best featu res of both to power plants involving the com bustion of a fuelinside a cycles’ high eficiency and low particulate em ission s. cham ber that results in the ex pansion of the air/elfu m ix ture In a conventional vehicle propelled by an internal com busto produce m echanical work . These internal com on busti tion engine, either S I or CI, m ost of the energy theinfuel goes engines are of two types: gasoline spark - ignitionnd a diesel to the ex haust and to the coolant ( radiator) , with about a q uarcom pression- ignition. The discussion also addresses alternater of the energy doing m echanical work to propel he tvehicle. tive power trains, including hybrid electrics. This is partially due to the fact that both engine types have therm odynam ic lim itations, but it is also because n a given i drive schedule the engine has to provide power over a range of Basic Engine Types speeds and loads; it rarely operates at its m osticient ef point. Gasoline engines, which operate on a relatively volatile This is illustrated by F igure 2 . 3 , which shows what is fuel, also go by the nam e Otto cycle engines ( after the person k nown as an engine eficiency m ap for an S I engine. It plots who is credited with building the irst work ing four - strok e the engine eficiency as functions of torq ue and speed. The internal com bustion engine) . In these engines, ark a sp plug is plot in F igure 2 . 3 represents the engine eficiency contours in used to ignite the air/ fuel m ix ture. Over the years , variations units of brak e- speciic fuel consum ption ( gram k silowattper of the conventional operating cycle of gasoline engines have hour) and relates torq ue in units of brak e m ean ective eff been proposed. A recently popular variation is the A tk inson pressure ( k ilopascals) . F or best eficiency, the ineeng should cycle, which relies on changes in valve tim ing to mi prove efoperate over the narrow range indicated by the roughly round iciency at the ex pense of lower peak power capabili ty. S ince contour in the m iddle; this is also referred to later in the chapin all cases the air/ fuel m ix ture is ignited bypark a s , this ter as the m ax im um engine brak e therm al eficiency ηb, m )ax. ( report refers to gasoline engines as spark - ignition engines. In conventional vehicles, however, the engine needsto cover

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F U NDAMENTALS OF F U EL CONSU MP TION

F IGU R E 2 . 3 A n ex am ple of an engine eficiency r a spark m ap - ignition fo engine. S OU R CE: R eprinted ermwith ission p from ( 1 9 8 8 ) . Copyright 1 9 8 8 by the M cGraw- H , Inc. ill Com panies

the entire range of torq ue and speeds, and so, onverage, a the eficiency is lower. One way to im prove eficienc y is to use a sm aller engine and to use a turbocharger toncrease i its power output back to its original level. Thiseduces r friction in both S I and CI engines as well as pum ping osses. l 1 Increasing the num ber of gear ratios in the transmssion i also enables the engine to operate closer to the m ax im engine um brak e therm al eficiency. Other m ethods to ex pand e highth eficiency operating region of the engine, particularly in the lower torq ue region, are discussed in Chapters 4 dan5 . A s discussed in Chapter 6 , part of the reason that hyb rid electric vehicles show lower fuel consum ption is that they erm p it the internal com bustion engine to operate at m ore ficient e speed- load points. Com puter control, irst introduced to m eet the uel air/ f m ix ture ratio req uirem ents for reduced em issions both in CI and S I engines, now allows the dynam ic optimioniz at of engine operations, including precise air/ fuel mx iture control, spark tim ing, fuel injection, and valve m tiing. The m onitoring of engine and em ission control params by eter the onboard diagnostic system identiies em issionntrol co system m alfunctions. A m ore recent developm ent in propulsion system to s is add one or two electrical m achines and a battery to create a 1 “P um ping loss” refers to the energy dissipatedough thr luid friction and pressure gradients developed from the air low throu gh the engine. A m ore detailed ex planation is provided in Chapter 4 of isthreport.

H eywood

hybrid vehicle. S uch vehicles can perm it the intern al com bustion engine to shut down when the vehicle is stopped and allow brak e energy to be recovered and stored or f later use. H ybrid system s also enable the engine to be wnsiz do ed and to operate at m ore eficient operating points. lthough A there were hybrid vehicles in production in the 1 902s, they could not com pete with conventional internal com tion bus engines. W hat has changed is the greater need toduce re fuel consum ption and the developm ents in controls, batte ries, and electric drives. H ybrids are discussed in Chapt er 6 , but it is safe to say that the long- term future of m r oto vehicle propulsion m ay lik ely include advanced com bustion ngines, e com bustion engine- electric hybrids, electric plugn hybrids, i hydrogen fuel cell electric hybrids, battery electrics, and m ore. The challenge of the nex t generation of propu lsion system s depends not only on the developm ent of the propulsion technology but also on the associated fuel or energy infrastructure. The large capital investm ent in mufacturan ing capacity, the m otor vehicle leet, and the assoc iated fuel infrastructure all constrain the rate of transition to new technologies. Combustion-Related Traits of SI Versus CI Engines The com bustion process within internal com bustion engines is critical for understanding the perform an ce of S I versus CI engines. S I- engine com bustion occurs ainlym by turbulent lam e propagation, and as turbulence tensity in

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ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

tends to scale with engine speed, the com bustionterval in in ogy. Im plem enting certain engine technologies meq ay uire r the crank - angle dom ain rem ains relatively constant throughchanges in fuel properties, and vice versa. A lthoug h the out the speed range ( at constant intak e- m anifold essure pr and com m ittee charge is not to assess alternative liq d fuels ui engines having a conventional throttle) . Thus, comustion b ( such as ethanol or coal- derived liq uids) that mt replace igh characteristics have little effect on the ability of this type gasoline or diesel fuels, it is within the com m e itte charge of engine to operate successfully at high speeds. Therefore, to consider fuels and the properties of fuels as they pertain this type of engine tends to have high power density ( e. g. , to im plem enting the fuel econom y technologies ssed discu horsepower per cubic inch or k ilowatts per liter) om c pared to within this report. its CI counterpart. CI engine com bustion is governe d largely Early engines burned coal and vegetable oils, but their by m eans of the processes of spray atom iz ation,oriz vapause was very lim ited until the discovery and ex ploi tation of tion, turbulent diffusion, and m olecular diffusion. Therefore, inex pensive petroleum . The lighter, m ore volatile raction f CI com bustion, in com parison with S I com bustion, less is of petroleum , called gasoline, was relatively easy to burn and im pacted by engine speed. A s engine speed increases , the m et the early needs of the S I engine. A heavier, ss volatile le com bustion interval in the crank - angle dom ain also increasesfraction, called distillate, which was slower to burn, m et the and thus delays the end of com bustion. This late denof com early needs of the CI engine. The power and eficiency of bustion delays burnout of the particulates that are the last to early S I engines were lim ited by the low com pressio n ratios form , subjecting these particulates to therm al qching. uen req uired for resistance to pre- ignition or k nock. ing This The conseq uence of this q uenching process is thatarticup lim itation had been addressed by adding a lead addi tive late em issions becom e problem atic at engine speeds well com m only k nown as tetraethyl lead. W ith the need to rem ove below those associated with peak power in S I engine s. This lead because of its detrim ental effect on catalytic aftertreatultim ately lim its the power density ( i. e. , power r unit peof m ent ( and the negative environm ental and hum anctsim pa displacem ent) of CI diesel engines. of lead) , k nock resistance was provided by further changing W hile power density gets m uch attention, torq ue sityden the organic com position of the fuel and initiallyybreducing in m any ways is m ore relevant. Therm al auto ignitio n in S I the com pression ratio and hence the octane req uirem ent of engines is the process that lim its torq ue densitynda fuel the engine. S ubseq uently, a better understandingengine of eficiency potential. Typically at low to m oderatengine e com bustion and better engine design and control all owed speeds and high loads, this process yields com busti on of increasing the com pression ratios back to and event ually any fuel/ air m ix ture not yet consum ed by the desire d lam ehigher than the pre- lead- rem oval levels. The recent reduction propagation process. This type of com bustion is typ ically of fuel sulfur levels to less than 1 5 parts per mlionil ( ppm ) referred to as engine k nock , or sim ply k nockis .process If th levels enabled m ore effective and durable ex haust ftertreata occurs prior to spark ignition, it is referred tosapre- ignition. m ent devices on both S I and CI engines. ( This is typically observed at high power settings.) K nock The m ain properties that affect fuel consum ption in and pre- ignition are to be avoided, as they both le ad to very engines are shown in Table 2 . 1 . The table shows t,thaon a high rates of com bustion pressure and ultim atelycom to povolum e basis, diesel has a higher energy content,alled c heat nent failure. W hile approaches such as turbochargin g and of com bustion, and higher carbon content than gasol ine; thus, direct injection of S I engines alter this picture om s ewhat, on a per gallon basis diesel produces alm ost 1 5 cent per m ore the fundam entals rem ain. CI diesel engines, however , are CO2. H owever, on a weight basis the heat of com bustion of not k nock lim ited and have ex cellent torq ue charact eristics diesel and gasoline is about the sam e, and so is ethcarbon at low engine speed. In the European m ark et, the popularity content. One needs to k eep in m ind that this differ ence in of turbocharged CI diesel engines in light- duty vehicle segenergy content is one of the reasons why CI engines have m ents is not only driven by the econom ics of fuel conom e y lower fuel consum ption when m easured in term sllons of ga but also by the “fun- to- drive” elem ent. That is,eqatual enrather than in term s of weight. P rocessing crude l into oi fuels gine displacem ent, the turbocharged diesel tends to deliver for vehicles is a com plex process that uses hydroge n to break superior vehicle launch perform ance as com paredhwit that of its naturally aspirated S I engine counterpart. TA BL E 2 . 1

FUELS The fuels and the S I and CI engines that use them ave h co- evolved in the past 1 0 0 years in response to roved im p technology and custom er dem ands. Engine efficiencie s have im proved due to better fuels, and reineriesearable to provide the fuels dem anded by m odern engines atower al cost. Thus, the potential for fuel econom y im provem ent m ay depend on fuel attributes as well as on engine technol-

P roperties of F uels

L ower L ower H eat of H eat of Carbon Carbon Com bustion Com bustionD ensity Content Content ( Btu/ gal) ( Btu/ lb) ( lb/ gal) ( g/ gal) ( g/ lb) Gasoline 1 1 6 ,1 0 0 D iesel 1 2 8 ,5 0 0 Ethanol ( E8 5 ) 7 6 , 3 0 0

1 8 ,6 9 0 1 8 ,4 0 0 1 1 ,5 8 0

6 .2 1 6 .9 8 6 .5 9

2 ,4 2 1 2 ,7 7 8 1 ,5 6 0

S OU R CE: A fter GR EET P rogram , A rgonne National atory, L abor http:/ / www. transportation. anl. gov/ m odeling_ sim on/ GR ulatiEET/ .

3

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

F U NDAMENTALS OF F U EL CONSU MP TION

down heavy hydrocarbons into lighter fractions. This is com m only called crack ing. D iesel fuel req uires less olecular “m m anipulation” for the conversion of crude oil into useful fuel. S o if one wants to m inim iz e the barrels of crude l used oiper 1 0 0 m iles, diesel would be a better choice than oline. gas Ethanol as a fuel for S I engines is receiving m uch attention as a m eans of reducing dependence on im port ed petroleum and also of producing less greenhouse gas ( GH G) . Today ethanol is blended with gasoline atout ab 1 0 percent. P roponents of ethanol would lik e tothe see greater availability of a fuel called E8 5 , which s ai blend of 8 5 percent ethanol and 1 5 percent gasoline. Theofuse 1 0 0 percent ethanol is widespread in Braz il, but it isunlik ely to be used in the U nited S tates because engines have dificulty starting in cold weather with this fuel. The effectiveness of ethanol in reducing GH G is aontroc versial subject that is not addressed here, since it generally does not affect the technologies discussed in this report. It is interesting to note that in a very early period of gasoline shortage, it was touted as a fuel of the future ( F oljam e, 1b 9 1 6 ) . Ethanol has about 6 5 percent of the heat of com ion bust of gasoline, so the fuel consum ption is roughly 5percent 0 higher as m easured in gallons per 1 0 0 .mEthanol iles has a higher octane rating than that of gasoline, and this is often cited as an advantage. Norm ally high octanenables e increases in the com pression ratio and hence eficie ncy. To tak e advantage of this form of eficiency increase, the engine would need to be redesigned to accom m odate an incre ased com bustion ratio. F or technical reasons the im m prove ent with ethanol is very sm all. A lso, during any transi tion period, vehicles that run on 8 5 to 1 0 0 percent anoleth m ust also run on gasoline, and since the com pression rat io cannot be changed after the engine is built, the higher octane rating of ethanol fuel has not led to gains in eficiency. A way to enable this eficiency increase is to m odify the Sengine I so that selective ethanol injection is allowed. This technology is being developed and is further discussed in Chapter 4 of this report.

17

relect legal com pliance with the CA F E req uirem andents thus do not include EP A ’s adjustm ents for its ing labelprogram , as described below. A lso discussed belowsom are e technologies—such as those that reduce air- conditioning power dem ands or req uirem ents—that im prove onfuelroad econom y but are not directly captured in the F TP . Com pliance with the NH TS A ’s CA F E regulation s depend on the city and highway vehicle dynam om eter tests eveld oped and conducted by the EP A for its ex haust em ion iss regulatory program . The results of the two testsearcom bined ( harm onic m ean) with a weighting of 5 5 percent and city 4 5 percent highway driving. M anufacturers self- certify their vehicles using preproduction prototypes representative of classes of vehicles and engines. The EP A then condu cts tests in its laboratories of 1 0 to 1 5 percent of thecles vehito verify what the m anufacturers report. F or its labeling gram pro , the EP A adjusts the com pliance values of fuel econo m y in an attem pt to better relect what vehicle owners act ually ex perience. The certiication tests yield fuel consu m ption ( gallons per 1 0 0 m iles) that is about 2 5 percent tter ( less be than) EP A - estim ated real- world fuel econom sis y. of A naly the 2 0 0 9 EP A fuel econom y data set for m 0ore 0 than 0 1 , vehicle m odels yields a m odel- averaged difference of about 3 0 percent. The certiication test fails to capture the full array of driving conditions encountered during vehicle operations. Box 2 . 1 provides som e of the reasons why the cation certii test does not relect actual driving. Beginning with m odel year 2 0 0 8 , the EP A began collecting data on dditional three a test cycles to capture the effect of higher speed and acceleration, air- conditioner use, and cold weather. These data are part of air pollution em ission com pliance testing ut not b fuel econom y or proposed greenhouse gas com pliance. Hver, owe the results from these three test cycles will be us ed with the two F TP cycles to report the fuel econom y on the hicle ve label. Table 2 . 2 sum m ariz es the characteristics the iveoftest schedules. This additional inform ation guides theelection s of a correction factor, but an understanding of fuel consum ption based on actual in- use m easurem ent is lack ing. The unfortunate conseq uence of the disparity between FUEL ECONOMY TESTING AND REGULATIONS the oficial CA F E ( and proposed greenhouse gas regul ation) The regulation of vehicle fuel econom y req uires eproar certiication tests and how vehicles are driven in use is that ducible test standard. The test currently uses a driving cycle m anufacturers have a dim inished incentive to design vehicles or test schedule originally developed for em issions regulation, to deliver real- world im provem ents in fuel econom if such y which sim ulated urban- com m ute driving in L ossAin ngeleim provem ents are not captured by the oficial test. S om e ex the late 1 9 6 0 s and the early 1 9 7 0 s. Thisariously cycle is v am ples of vehicle design im provem ents that are com not pletereferred to as the L A - 4 , the urban dynam om ing eter drivly represented in the oficial CA F E test are m ore icient ef air schedule ( U D D S ) , and the city cycle. The ronm U . S ental . Envi conditioning; cabin heat load reduction through heat- resistant P rotection A gency ( EP A ) later added a second to cycle better glaz ing and heat- relective paints; m ore eficient wer posteercapture som ewhat higher- speed driving: this cycle s ki nown ing; eficient engine and drive train operation at all speeds, as the highway fuel econom y test ( H W F ET) driving hed- sc accelerations, and road grades; and reduced drag toinclude the ule, or the highway cycle. The com bination of these two test effect of wind. The certiication tests give no incentive to procycles ( weighted using a 5 5 percent city cycle and 4 5 percent vide inform ation to the driver that would im prove perational o highway cycle split) is k nown as the F ederal Test rocedure P eficiency or to reward control strategies that com ensate p for ( F TP ) . This report focuses on fuel consum ptionthat data driver characteristics that increase fuel consum pti on.

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ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

The m easurem ent of the fuel econom y of hybrid,- plug in hybrid, and battery electric vehicles presents additional dificulties in that their perform ance on the city ersus v highway driving cycles differs from that of convent ional vehicles. R egenerative brak ing provides a greateringain city driving than in highway driving. P lug- in hybri ds present an additional com plex ity in m easuring fuel econom sincey this req uires accounting of the energy derived fromthe grid. The S ociety of A utom otive Engineers ( S A E) tly is curren developing recom m endations for m easuring the em ons issi and fuel econom y of hybrid- electric vehicles, inclu ding plug- in and battery electric vehicles. General M rs otoCom pany recently claim ed that its Chevrolet V olt exdedten range electric vehicle achieved city fuel econom y of ateast l 2 3 0 m iles per gallon, based on developm ent testing gusin a draft EP A federal fuel econom y m ethodology for thenglabeli of plug- in electric vehicles ( General M otors Com pany ress p release, A ugust 1 1 , 2 0 0 9 ) .

BOX 2.1 Shortcomings of Fuel Economy Certification Test • Dynamometer test schedules. The UDDS and HWFET test schedule (driving cycles) were adopted in 1975 to match driving conditions and dynamometer limitations of that period. Maximum speed (56.7 mph) and acceleration (3.3 mph/sec, or 0-60 mph in 18.2 sec) are well below typical driving. The 55 percent city and 45 percent highway split may not match actual driving. Recent estimates indicate that a weighting of 57 percent highway and 43 percent city is a better relection of current driving patterns in a number of geographic areas. • Test vehicles. The preproduction prototypes do not match the full range of vehicles actually sold. • Driver behavior. The unsteady driving characteristic of many drivers increases fuel consumption. • Fuel. The test fuel does not match current pump fuel. • Air conditioning. Air conditioning is turned off during the certiication test. In addition to overestimating mileage, there is no regulatory incentive for manufacturers to increase air-conditioning eficiency. However, there is substantial market incentive for original equipment manufacturers both to increase air-conditioning eficiency and to reduce the sunlight-driven heating load for customer comfort beneits. • Hills. There are no hills in the EPA certiication testing. • Vehicle maintenance. Failure to maintain vehicles degrades fuel economy. • Tires and tire pressure. Test tires and pressures do not generally match in-use vehicle operation. • Wind. There is no wind in the EPA certiication testing. • Cold start. There is no cold start in the EPA CAFE certiication testing. • Turns. There is no turning in the EPA certiication testing.

CUSTOMER EXPECTATIONS The objective of this study is to evaluate technologies that reduce fuel consum ption without signiicantlyeducing r custom er satisfaction. A lthough each vehicle m cturer anufa has a proprietary way of deining very precisely how its vehicle m ust perform , it is assum ed here thatollowing the f param eters will rem ain essentially constant as technolothe gies that reduce fuel consum ption are considered: • Interior passenger volum e; • Trunk space, ex cept for hybrids, where trunk cespa m ay be com prom ised; • A cceleration, which is m easured in a varietytests, of such as tim e to accelerate from 0 to 6 0 m ph, 0 , 0 to 3 5 5 to 6 5 ( passing) , 3 0 to 4 5 , entrance way, ram p to high etc. ;

TA BL E 2 . 2 Test S chedules U sed in the U nited for MS tates ileage Certiication Test S chedule D riving S chedule A ttributes Trip type

A ir Conditioning HET) ighway ( H H W igh SF peed ( U S( S 0 6C0) 3 )

U rban ( U D D S )

L ow speeds in stop- and-F ree- low trafic at go urban trafic highway speeds

Top speed 5 6 . 7 m ph A verage speed 1 9 . 6 m ph M ax im um acceleration 3 . 3 m ph/ sec S im ulated distance 7 . 4 5 m i. Tim e 2 2 . 8 m in S tops 1 7 Idling tim e 1 8 % of tim e L ab tem perature 6 8 - 8 6 °F V ehicle air conditioning Off

H igher speeds; harder acceleration and brak ing

5 9 . 9 m ph 4 8 . 2 m ph 3 . 2 m ph/ sec 1 0 . 3 m i. 1 2 . 7 5 m in None 5 None Off

S OU R CE: A fter http:/ / www. fueleconom y. gov/ t_ feg/ schedules. fe_ tes shtm l.

Off

Cold Tem perature U D D S

A ir conditioning use City test with colder under hot am bient outside tem perature conditions

8 0 . 3 m ph 4 8 m ph sec 8 . 45 0. 1 mm ph/ ph/ sec 8 m i. 1 0 m in 5 7 % of tim e 1 9 9 5 °F On

5 4 . 8 m ph 5 6 .7 2 1 . 4 m ph 1 9 .6 3 . 3 m ph/ sec 3 .5 8 7 .4 5 1 0 m in 2 2 .8 1 7 % of timofetim e 1 8 % 2 0 °F Off

m ph m ph m i. m in

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

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F U NDAMENTALS OF F U EL CONSU MP TION

TA BL E 2 . 3 A verage Characteristics of L ight- D uty is the vehicle m ass,V is the velocity, dV / dt is the rate of V ehicles for F our M odel Y ears change of velocity ( i. e. , acceleration or decelerat ion) , A is the frontal area, r is the tire rolling resistance coeficient, g o 1 9 7 5 1 9 8 7 1 9 9 8 2 0 0 8 is the gravitational constant, Iw is the polar m om ent of inertia A djusted fuel econom y ( m pg) 1 3 .1 2 2 2 0 .1 2 0 .8 of the four tire/ wheel/ ax le rotating assem blies, rw is its efW eight 4 ,0 6 0 3 ,2 2 0 3 ,7 4 4 4 ,1 1 7 fective rolling radius, and ρ is the density of air. This form H orsepower 1 3 7 1 1 8 1 7 1 2 2 2 of the tractive force is calculated at the wheels of the vehicle 0 to 6 0 acceleration tim e ( sec) 1 4 .1 1 3 .1 1 0 .9 9 .6 P ower/ weight ( hp/ ton) 6 7 .5 7 3 .3 9 1 . 3 and 1 0therefore 7 .9 does not consider the com ponents with in the vehicle system such as the power train ( i. e. , ional rotat inertia S OU R CE: EP A ( 2 0 0 8 ) . of engine com ponents and internal friction) . The tractive energy req uired to travel an increm ental • S afety and crashworthiness; and distance dS is FTR V dt , and its integral over all portions of • Noise and vibration. a driving schedule in which FTR > 0 ( i. e. , constant- speed driving and accelerations) is the total tractive- energy req uireThese assum ptions are very im portant. It is obvious that m ent, ETR. F or each of the EP A driving schedules, S ovran and reducing vehicle siz e will reduce fuel consum ption. A lso, the Blaser ( 2 0 0 6 ) calculated tractive energy fore anum larg ber of reduction of vehicle acceleration capability allows the use vehicles covering a broad range of param eter setsr0(, CD, A, of a sm aller, lower- power engine that operates clos er to its M) representing the spectrum of current vehicles. ey Ththen best eficiency. These are not options that will beconsidered. itted the data with a linear eq uation of the following form : A s shown in Table 2 . 3 , in the past 2 0 or sothe years, net result of im provem ents in engines and fuels has been   C A 4I  ETR increased vehicle m ass and greater acceleration cap ability ( 2 .2 ) = α r0 + β  D  + γ  1 + w2  MS Mrw   M   while fuel econom y has rem ained constant ( EP A ) ,. 2 0 0 8 P resum ably this tradeoff between m ass, acceleration , and fuel consum ption was driven by custom er dem and.s M as where S is the total distance traveled in a driving schedule, increases are directly related to increased siz e, he t shift from and α, β, and γ are speciic but different constants for the passenger cars to truck s, the addition of safety eq uipm ent U D D S and H W F ET schedules. S ovran and Blaser ( 2 0 such as airbags, and the increased accessory content. Note also identiied that a com bination of ive U D D S hreeand t that although the CA F E standards for light- duty senger pas H W F ET schedules very closely reproduces the EP A - com cars have been for 2 7 . 5 m pg since 1 9 9 0 , erage the leet avbined fuel consum ption of 5 5 percent U D D Sercent plus 4 5 p rem ains m uch lower through 2 0 0 8 due to lower CA HF W E F ET, and provided its values α, β, of andγ. standards for light- duty pick up truck s, sport utili ty vehicles The sam e approach was used for those portions of driva ( S U V s) , and passenger vans. ing schedule in which FTR < 0 ( i. e. , decelerations) , where the power plant is not req uired to provide energy for propulsion. In this case the rolling resistance and aerodynam icdrag TRACTIVE FORCE AND TRACTIVE ENERGY retard vehicle m otion, but their effect is not sufi cient to The m echanical work produced by the power plant is follow the driving cycle deceleration, and so som form e of used to propel the vehicle and to power the accessories. A s wheel brak ing is req uired. W hen a vehicle reaches he end t discussed by S ovran and Blaser ( 2 0 0 6 ) , the concepts of tracof a schedule and becom es stationary, all the k ic inet energy tive force and tractive energy are useful for understanding of its m ass that was acq uired when FTR > 0 has to have been the role of vehicle m ass, rolling resistance, and erodynam a ic rem oved. Conseq uently the decrease in k inetic energ y prodrag. These concepts also help evaluate the effectiveness duced by wheel brak ing is of regenerative brak ing in reducing the power plantenergy that is req uired. The analysis focuses on test sche dules and E BR MS = γ 1 + 4 I w Mrw 2 − α ′r0 − β ′ (C D A M . ( 2 .3 ) neglects the effects of wind and hill clim bing. The instantaneous tractive force (FTR) req uired to propel a vehicle is The coeficients a′ and b′ are also speciic to the test schedule and are given in the reference. Two observations are   I   dV of interest: ( 1 g) is the sam e for both m otoring and brak ing = FTR = R + D +  M + 4  W2   as it relates to the k inetic energy of the vehicle;( 2 ) since the  rW   dt  ( 2 .1 ) energy used in rolling resistance is r0 M g S, the sum of α   I W   dV V2 and α′ is eq ual to g. r0 Mg + C D A ρ +  M + 4  2   S ovran and Blaser ( 2 0 0 6 ) considered 2 , 5 0from 0 vehicles 2  rW   dt  the EP A database for 2 0 0 4 and found that their tions eq ua where R is the rolling resistance, D is the aerodynam ic drag itted the tractive energy for both the U D D S andET H W F with CD representing the aerodynam ic drag coeficient,M schedules with an r = 0 . 9 9 9 , and the brak ing energy with an

(

)

)

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 0

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Effect of Driving Schedule r = 0. 9 9 , where r represents the correlation coeficient based on least sq uares it of the data. It is evident from Table 2 . 5 that inertia is the m doinant To illustrate the dependence of tractive and brak in g energy com ponent on the U D D S schedule, while aerodynam rag ic d on vehicle param eters, S ovran and Blaser ( 2 0 0d the 6 ) use is dom inant on the H W F ET. The larger any comtheponent, following three sets of param eters. F undam entally he energy t greater the im pact of its reduction on tractive ene rgy. needed by the vehicle is a function of the rolling resistance, On the U D D S schedule, the m agnitude of reqk uired bra the m ass, and the aerodynam ic drag tim es frontal ea. By ar ing energy relative to tractive energy is large at all three com bining the last three into the results shown in Table 2 . 4 , vehicle levels, increasing as the m agnitude of the rolling and S ovran and Blaser ( 2 0 0 6 ) covered the entire 2leet 0 0in 4 . aerodynam ic resistances decreases. The high values are due The “high” vehicle has a high rolling resistance, and high to the m any decelerations that the schedule contain s. The aerodynam ic drag relative to its m ass. This would e typical b brak ing energy m agnitudes for H W F ET are sm seall becau of a truck or an S U V . The “low” vehicle req wuires tractive lo of its lim ited num ber of decelerations. energy and would be typical for a future vehicle. These three In vehicles with conventional power trains, the wheelvehicles cover the entire spectrum in vehicle desig n. brak ing force is frictional in nature, and so allhet vehicle The data shown in Table 2 . 5 were calculated using hese t k inetic energy rem oved is dissipated as heat. H er, owev in values. The low vehicle has a tractive energy req ui rem ent hybrid vehicles with regenerative- brak ing capabilit y, som e that is roughly two- thirds that of the high vehicle. It should of the brak ing energy can be captured and then recycled also be noted that as the vehicle design becom es mre oeffor propulsion in segm ents of a schedule whereFTR > 0 . icient ( i. e. , the low vehicle) , the fraction ofrgy enereq uired This reduces the p o w er p energy l ant req uired to provide to overcom e the inertia increases. A s ex pected,both for the ETR necessary for propulsion, thereby reducing fuel driving schedules the no rmal iz ed tractive energy, ETR /MS, consum ption. The signiicant increase in norm aliz tractive ed decreases with reduced rolling and aerodynam ic resi stances. energy (ETR/MS) with decreasing rolling and aerodynam ic W hat is m ore signiicant, however, is that at each evel, l the resistances m ak es reduction of these resistancesen evmo re actu al tractive energy is strongly dependent on vehicle m ass, effective in reducing fuel consum ption in hybrids with regenthrough its inluence on the rolling and inertia components. erative brak ing than in conventional vehicles. Therelatively This gives m ass reduction high priority in effortsto reduce sm all values of brak ing- to- tractive energy on the W HF ET vehicle fuel consum ption. indicate that the fuel consum ption reduction capabi lity of regenerative brak ing is m inim al on that schedule. s a result, A hybrid power trains only offer signiicant fuel consum ption reductions on the U D D S cycle. H owever, as ut pointed in o Chapter 6 , hybridiz ation perm its engine downsizand ing TA BL E 2 . 4 V ehicle Characteristics engine operation in m ore eficient regions, and this applies V ehicle ro CdA/ M to the H W F ET schedule also. H igh M id L ow

0 .0 1 2 0 .0 0 9 0 .0 0 6

0 .0 0 0 6 5 0 .0 0 0 5 0 .0 0 0 3

Effect of Drive Train

S OU R CE: Based on S ovran and Blaser ( 2 0 0 6 ) .

Given the tractive energy req uirem ents ( plus idling and accessories) , the nex t step is to represent the efi ciency of the power train. The power delivered to the output shaft of the TA BL E 2 . 5 Estim ated Energy R eq uirem ents ee for theengine Thr is term ed theb rak e o u tp u t and p o should w er, not be S ovran and Blaser ( 2 0 0 6 ) V ehicles in Table the2 . 4 for confused with the b rak ing energ m yentioned in the previous U D D S and H W F ET S chedules section. The brak e output power,Pb, of an engine is the difference between its indicated power, Pi, and power req uired R olling A erodynam ic Brak ing/ ETR/MS R esistance D rag Inertia Tractive for pum ping, Pp; friction,Pf; and engine aux iliaries, Pa ( e. g. , ( Norm aliz ed) (% ) (% ) (% ) (% ) fuel, oil, and water pum ps) . U D D S V ehicle H igh 0 . 3 2 M id 0 .2 8 L ow 0 .2 4

2 8 2 4 1 9

2 2 1 9 1 4

5 0 5 7 6 8

3 6 4 5 5 8Brak

H W F ET V ehicle H igh 0 . 3 4 M id 0 .2 7 L ow 0 .1 9

3 2 3 0 2 9

5 6 5 4 4 7

61 3 1 6 2 4

1 0 1 8

(

Pb = Pi − Pp − Pf + Pa

)

( 2 .4 )

e therm al eficiency is the ratio of brak e power output to the energy rate into the system ( the m ass low te of ra fuel tim es its energy density) .

ηb = ηi −

Pp m f H f

−

(P + P ) f

a

m f H f

( 2 .5 )

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 1

F U NDAMENTALS OF F U EL CONSU MP TION

The brak e therm al eficiencyηisb, whileηi is the indicated therm al eficiency, and Hf is the lower heating value of the fuel. This eq uation provides the m eans for relating pum ping losses, engine friction, and aux iliary load to the overall engine eficiency. Eq uations for fuel use during bra k ing and idling are not shown here but can be found in S ovra n and Blaser ( 2 0 0 3 ) , as can the eq uations for average edulesch and m ax im um engine eficiency. U ltim ately the fuel consum ption is given by Eqn 2uatio .6 :   E  TR + E Accessories  ∗  ∗  η ∗ g∗ =  dr  + gbraking + gidling ∗   η H η  b   f b ,max  η b ,max   

( 2 .6 )

fact that the effects of the three principal aspects of vehicle design—vehicle m ass, rolling resistance, and aerody nam ic drag—can be used to calculate precisely the am ountof energy needed to propel the vehicle for any k ind ofdrive schedule. F urther, the eq uations developed highligh t both the effect of the various param eters involved andt athe sam e tim e dem onstrate the com plex ity of the problem hough . A lt the eq uations provide understanding, in the end est im ating the fuel consum ption of a future vehicle m ust beterm de ined by F S S m odeling and ultim ately by constructing m aonde stration vehicle.

DETAILED VEHICLE SIMULATION

The com m ittee obtained results of a study by R o, icard Inc. ( 2 0 0 8 ) for a com plete sim ulation forma 2ry0pas0 7 Ca senger car. This F S S is discussed further in Chapte r 8 ; one where in addition to the term s deined earlier,g *is the fuel ∗ ∗ set of results is used here for illustration. Table2 . 6 gives the consum ption over the driving schedule,gbraking and gidling speciications of the vehicle in term s of the paramterse used represent the fuel consum ed during idling and brakng,i Hf ∗ in the sim ulation. is the fuel density of fuel, ηdr is the average drive train eficiency for the schedule, hb ,max is the m ax im um engine F irst, the tractive energy and its com ponents foris th vehicle were calculated to illustrate how these vary with brak e therm al eficiency, ηb∗ is the average engine brak e different test schedules. A lthough the U S 0 6 escribed cycle d therm al eficiency, and EAccesso riesis the energy to power the in Table 2 . 2 is not yet used for fuel econom yication, certi it accessories. The term hb ,maxis repeated in the denom inator is interesting to note how it affects the energy distribution. to show that to m inim iz e fuel consum ption the ionfract in Table 2 . 7 shows the results. Energy to the wheels nd arolling the denom inator should be as large as possible. Thu s things resistance increase from the U D D S to the U Sthe0 6 , with should be arranged so that the average engine eficiency be total tractive energy req uirem ent being alm ost le doub that as close to the m ax im um . of the U D D S . The aero energy req uirem ent from increases The principal term in Eq uation 2 . 6 is the brack eted the U D D S to the H W F ET, but it is not m in uch increased term . Clearly fuel consum ption can be reduced by ducre going to the U S 0 6 , in spite of the higher peakd. spee W hat ing ETR and EAccesso ries. It can also be reduced by increasing enefor ηb∗ /hb ,max. A s stated earlier, this can be done by downsizg in is som ewhat surprising is the am ount of brak ingrgy the U D D S and the U S 0 6 com pared to the Hs W F ET. the engine or by increasing the num ber of gears in the transwhere hybrids ex cel. m ission so that average engine brak e therm al eficie ncy, F or the highway, rolling resistance and aero dom te, inaand ηb∗ , is increased. Eq uation 2 . 6 ex plains why reducing rolling very little energy is dissipated in the brak es. Aexs pected, resistance or aerodynam ic drag without changes inngine e the aero is dom inant for the U S 0 6 , where it isthan m ore or transm ission m ay not m ax im iz e the beneit, it m since ay m oveηb∗ /hb ,max farther from its optim um point. In other words, changing to lower- rolling- resistance tires ithout w m odifying the power train will not give the full be neit. TA BL E 2 . 6 S peciications of V ehicle S im ulated by The tractive energy ETR can be precisely determ ined given R icardo, Inc. ( 2 0 0 8 ) just three param eters, rolling resistance r0, the product of aero coeficient and frontal area CDA, and vehicle m ass M. M ass 1 ,6 4 4 k g H owever, m any of the other term s in Eq uatione 2dif. 6 ar C 0 .3 0 D icult to evaluate analytically. This is especially true of the A 2 . 32 m engine eficiencies, which req uire detailed engine m aps. Thus converting the tractive energy into fuel consum ption is best done using a detailed step- by- step sim ulati on. This TA BL E 2 . 7 Energy D istribution for V arious S( in chedules sim ulation is usually carried out by break ing down the test k ilowatt- hours) schedule into 1 - second intervals, com putingEthe TR for each Total Total Total Brak ing/ interval using detailed engine m aps along with tran sm ission Tractive R olling A erodynam Brak ic ing Tractive characteriz ations, and adding up the interval value s to get Energy R esistance D rag Energy ( % ) the totals for the drive cycle analyz ed. S uch a sim ulation is U rban 1 .2 5 0 0 .4 4 0 0 .3 1 0 0 .5 0 0 4 0 freq uently called a full system sim ulation, F S S . H ighway 1 . 7 6 0 0 .6 1 0 1 . 0 0 0 08 . 5 20 . 1 5 0 The discussion above on tractive energy highlights the U S 0 6 2 .3 9 0 0 .6 6 0 1 .1 7 0 0 .5 6 0 2

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 2

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Full System Simulation by Ricardo – 2007 Camry UD D S half the total tractive energy. Note, though, that the U S 0 6 has a signiicant am ount of energy dissipated in the brak es. A ero A ccessories A s discussed earlier, som e people will drive inDa UD S 0.31 k W h 0.20 k W h 2.4% 3.5 % environm ent and som e on the highway. A vehicle m opti iz ed for one type of driving will not perform as well fo r the other, T ransmission / T ire Rolling and it is not possible to derive a schedule that its all driving Fuel Input T o w h eels T orq ue Conv . / / Slip 8 .71 k W h E ngine 1 .25 k W h conditions. Table 2 . 7 shows the im practicallyveloping of de D riv eline L osses 0.44 k W h 1 00% 1 4.3% 0.47 k W h 5 .4% 5 .0% a test that duplicates the actual driving patterns. Note that the data in Table 2 . 7 show the actual ene rgy in E x h aust / Cooling / k ilowatt- hours used to drive each schedule. The uni t of total B rak ing Friction L osses 0.5 0 k W h energy is used to allow for an easier com parison be tween the 6.78 k W h 77.9 % 5 .8 % schedules on the basis of energy distribution. S inc e as shown in Table 2 . 2 , the distances are 7 . 4 5 m ilesU for D the D S , 1 0 . 3 m iles for the H W F ET, and 8 m ilesthe for the U SFull0 System 6 , Simulation by Ricardo – 2007 Camry H W FE T energies should be divided by distance to provide the energy A ero A ccessories req uired per m ile. 1 .00 k W h 0.1 6 k W h 2.0% 1 2.1 % A n F S S provides a detailed break down of where the energy goes, som ething that is not practical to do with real T ransmission / T ire Rolling vehicles during a test schedule. F igure 2 . 4 illustr ates the total Fuel Input T o w h eels T orq ue Conv . / / Slip 8 .27 k W h E ngine 1 .76 k W h energy distribution in the m idsiz e car, visuallyentifying id D riv eline L osses 0.61 k W h 1 00% 21 .3% 0.48 k W h 5 .8 % 7.4% where the energy goes. Table 2 . 8 shows the fuel consum ed for this vehicle for the U D D S , H W F ET, and U S 0 6 schedules. atioEficiency is the r E x h aust / Cooling / B rak ing Friction L osses 0.1 5 k W h of tractive energy divided by “fuel energy input. ”Clearly this 5 .8 6 k W h 70.9 % 1 .8 % gives a m ore succinct picture of the eficiency ofnainternal com bustion engine power train in converting fuel topropel Full System Simulation by Ricardo – 2007 Camry US06 a vehicle and to power the accessories. D ependingnothe drive schedule, it varies from 1 5 to 2 5 percent cluding ( inthe A ero A ccessories energy to power accessories) . This range is signiic antly less 1 .1 7 k W h 0.1 1 k W h 1 .1 % 1 1 .6% than the peak eficiencyhb ,maxdiscussed earlier. In addition to the speciic operating characteristics of T ire Rolling T ransmission / the particular com ponents, the com putation of engin e fuel Fuel Input T o w h eels / Slip T orq ue Conv . / 1 0.03 k W h E ngine 2.38 k W h consum ption depends on the following inputs: ( 1 e) transth D riv eline L osses 0.66 k W h 1 00% 23.7% 0.61 k W h 6.1 % 6.6% m ission gear at each instant during the driving sch edule and ( 2 ) the engine fuel consum ption rate duringk bra ing E x h aust / Cooling / and idling. None of these details is available, sothe data in B rak ing Friction L osses 0.5 6 k W h Table 2 . 8 should be considered as an illustrativex eam ple 6.9 3 k W h 69 .1 % 5 .5 % of the energy distribution in 2 0 0 7 m odel- year lesvehic with conventional S I power trains. F IGU R E 2 . 4 Energy distribution obtained through l- system ful

FINDINGS AND RECOMMENDATIONS

sim ulation for U D D S ( top) , H W F ET ( m( bottom iddle) , and ). U S 0 6 S OU R CE: R icardo, Inc. ( 2 0 0 8 ) .

Finding 2.1 :F uel consum ption has been shown to be the fundam ental m etric to judge fuel eficiency im provem ents from both an engineering and a regulatory viewpoint . F uel econom y data cause consum ers to undervalue sm -all in TA BL E 2 . 8 R esults of F ull S ystem S im ulation ( energy creases ( 1 - 4 m pg) in fuel econom y for vehicles he 1 5in -t to values in k ilowatt- hours) 3 0 - m pg range, where large decreases in fuel consum tion p Total Tractive F uel Input P ower Train can be realiz ed with sm all increases in fuel econom y. F or Energy Energy Eficiency ( % ) ex am ple, consider the com parison of increasingmthepg 1 .2 5 0 8 .5 9 1 4 .6 rating from 4 0 m pg to 5 0 m pg, where thesaved total fuel U rban 1 .7 6 0 8 .0 1 2 2 .0 in driving 1 0 , 0 0 0 m iles is only 5 0 gallons, d tocom 5 0 0pare H ighway U S 0 6 2 .3 9 0 9 .6 6 2 4 .7 gallons for a change from 1 0 m pg to 2 0 m pg.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 3

F U NDAMENTALS OF F U EL CONSU MP TION

Recommendation 2.1 :Because differences in the fuel consum ption of vehicles relate directly to fuel savings, thebella ing on new cars and light- duty truck s should includ e inform ation on the gallons of fuel consum ed per 1 00 m traveled iles in addition to the already- supplied data on fuel econom y so that consum ers can becom e fam iliar with fuel consumasption a fundam ental m etric for calculating fuel savings. Finding 2.2: F uel consum ption in this report is evaluated by m eans of the two EP A schedules: U D D S T. and H In the opinion of the com m ittee, the schedules used to com pute CA F E should be m odiied so that vehicle data test better relect actual fuel consum ption. Ex cludingmso e driving conditions and accessory loads in determ ining A C F E discourages the introduction of certain technologies into the vehicle leet. The three additional schedules recently adopted by the EP A for vehicle labeling purposes—ones that capture the effects of higher speed and acceleration, air- onditioner c use, and cold weather—represent a positive step forward, but further study is needed to assess to what degree the new test procedures can fully characteriz e changes in in- usevehicle fuel consum ption.

REFERENCES

EP A ( U . S . Environm ental P rotection A gency) ight-. D2 0uty0 A8 .utoL m otive Technology and F uel Econom y Trends: 1 9 ough 7 5 2Thr 0 0 8 . EP A 4 2 0 - R - 0 8 - 0 1 5 . S eptem ber. W ashington, D . C. F ischer, C. 2 0 0 9 . L et’s turn CA F E regulation head. on Issue its Brief No. 0 9 - 0 6 . M ay. R esources for the F uture, W. C.ashington, D F oljam be, E. S . 1 9 1 6 . The autom obile fuel S Asituation. E Transactions, V ol. 1 1 , P t. I. General M otors Com pany. 2 0 0 9 . Chevy V oltpggets city2 EP 3 0A mrating. P ress release. A ugust 1 1 . H W eywood, F E J . B. , 1 9 8 8 . Internal Com bustion Engine F undam entals. M cGraw H ill, New Y ork . K ettering, C. F . 1 9 1 8 . M odern aeronautic S Aengines. E Transactions, V ol. 1 3 , P t. II. L arrick , R . , and J . S oll. 2 0 0 8 . The cience m pg 3illusion. 2 0 ( 5S 8 8 3 ) :1 5 9 3 1 5 9 4 . R icardo, Inc. 2 0 0 8 . A S tudy of P otential essEffectiven of Carbon D iox ide R educing V ehicle Technologies. P repared for the. U Environm .S ental P rotection A gency. EP A 4 2 0 - R - 0 8 - 0 0 4- .C-Contract 0 6 - 0 No. 0 3 EP . W ork A ssignm ent No. 1 - 1 4 . A nn A rbor, M ichigan. S ovran, G. , and D . Blaser. 2 0 0 3 . A contribution to understanding autom otive fuel econom y and its lim its. S A E P aper 2 0 0. SS3 A-A0 EE1InternaInterna-2 0 7 0 tional, W arrendale, P a. S ovran, G. , and D . Blaser. 2 0 0260. 0Q6 uantifying . Q uantifying tential the potential im the po pacts im ofpacts re- of regenerative brak ing on a vehicle’s tractive- fuel consum onptifor the U S , European and J apanese driving schedules. S A E P 2aper 0 0 6 -0 1 -0 6 6 4 . S A E International, W arrendale, P a.

Recommendation 2.2: The NH TS A and the EP A should review and revise fuel econom y test procedures sohat t they better relect in- use vehicle operating conditions and also better provide the proper incentives to m anufacture rs to produce vehicles that reduce fuel consum ption.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

3 Cost Estimation

INTRODUCTION

com ponent into the fundam ental m aterials, labor, d capital an req uired to m ak e it, and then to estim ate the ofcost every A s a general rule, reduced fuel consum ption comt es a nut and bolt and every step in the m anufacturing pr ocess a cost. The cost m ay be due to m ore ex pensive m aterials, ( K olwich, 2 0 0 9 ) . A potential advantage of odthis is that m eth increased m anufacturing com plex ity, or a tradeoff ith w total costs can be directly related to the costs of m aterials, other vehicle attributes such as power or siz e. Inaddition to labor, and capital so that as their prices change,cost estim ates increased m anufacturing costs, other costs of doing siness bu can be revised. H owever, this m ethod is dificult apply to to are lik ely to be affected to a greater or lesser de gree. These new technologies that have not yet been im plem ented in a indirect costs include research and developm ent ( RD &) , penm ass- production vehicle, whose designs are not yet inaliz ed sions and health care, warranties, advertising, mntaining ai a and whose im pact on changing related parts is notety k nown. dealer network , and proits. The m ost appropriateasure m eof D ifferences in cost estim ates from different source s arise cost for the purpose of evaluating the costs and beneits of fuel in a num ber of ways: econom y regulations is the long- run increase in ail ret price paid by consum ers under com petitive m ark et conditio ns.1 The • A ssum ptions about the costs of com m odities, r, labo retail price eq uivalent ( R P E) cost of decreasing el consum fu pand capital; tion includes not only changes in m anufacturing cos ts but also • J udgm ents about the changes in other vehicle com poany induced changes in indirect costs and proit. nents req uired to im plem ent a given technology; M ost m ethods for estim ating m anufacturing costs in beg • D einitions of “m anufacturing cost” and what item s are by identifying speciic changes in vehicle com ponent s or included in it; and designs, and they then develop individual cost estim ates for • A ssessm ents of the im pacts of technologiesdirect on in each affected item . M ost changes result in costreases, inc costs. but som e, such as the downsiz ing of a V 6 engine an I4 to , will reduce costs. Com ponent cost estim ates can ecom from This chapter discusses the prem ises, concepts, and m ethods a variety of sources, including interviews of original eq uipused in estim ating the costs of fuel econom y im em provent, m ent m anufacturers ( OEM s) and suppliers, prices optional of highlights areas where differences arise, and presents the com eq uipm ent, and com parisons of m odels with and utwitho the m ittee’s judgm ents on the k ey issue of R P E mactors. ark up f technology in q uestion. Total costs are obtained by adding up Inform ation on costs can be used with assum ptions the costs of changes in the individual com ponents. on payback periods, discount rates, price of fuel, and A n alternative m ethod, which has only just begunbeto m iles driven per year to provide an estim ate of the costused for estim ating fuel econom y costs, is to tear down a effectiveness of technologies. H owever, the statem nt of e task given to the com m ittee is to look at the and costsfuel consum ption beneits of individual technologies. Pform er 1 A s ex plained below, this rests on the prem isethe thatglobal autom oing costeffectiveness analysis was not included wi t hin the tive m ark et can be reasonably characteriz ed ( innom eco ic jargon) as either com m ittee’s task and was not done by the com m The ittee. a perfectly com petitive or a m onopolistically com titive pe m ark et. U nder such m ark et conditions, products are sold, in the onglrun, at their average accurate calculation of beneits of im proved fuel ef iciency cost of production, including a norm al rate of retu rn to capital but no ex cess is a com plex task that is being undertak en by ational the N proits. Increased costs of production will therefore be fully passed on to H ighway Trafic S afety A dm inistration ( NH TS eA ) and th consum ers. The total cost of resources plus the con sum ers’ surplus loss due U . S . Environm ental P rotection A gency ( EP of A their ) as part to the price increase is, to a close approx im ation, eq ual to the increase in current joint regulatory efforts. long- run retail price tim es the volum e of sales. 2 4

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

COST ESTIMATION

PREMISES

2 5

ignition ( CI) engine replaces a spark - ignition ( S I) engine, or a set of low- rolling- resistance tires places re In the com m ittee’s judgm ent, the concept of increa set with higher rolling resistance. W hat m atters is the m ental retail price eq uivalent cost is m ost appropr iate for change in R P E rather than the total R P E of the new the NH TS A ’s purposes because it best represents the l, ful technology. This req uires that an estim ate of the P RE long- run econom ic costs of increasing fuel economThe y. of the ex isting technology be subtracted from that of NH TS A has used the R P E m ethod in its rulem ak ings on the new technology. fuel econom y, for ex am ple in the inal rule for lmyear ode • Eq u ival ent vehicl e siz e and p erfo rmance . Estim at2 0 1 1 light- duty vehicles ( D OT/ NH TS A , 2 0 0 9 , pp. 3 4 6 ing the cost of decreasing fuel consum ption req uire s 3 5 2 ) . Increm ental R P E estim ates are intended resent to rep one to carefully specify a basis for com parison. Th e the average additional price that consum ers woulday p for a com m ittee considers that to the ex tent possible, el fu fuel econom y technology im plem ented in a typical hicle ve consum ption cost com parisons should be m ade at under average econom ic conditions and typical m anuf aceq uivalent acceleration perform ance and eq uivalent turing practices. These estim ates are intended toepresent r vehicle siz e. Other vehicle attributes m atter asell,w long- run, high- volum e, industry- average production costs, such as reliability, noise, and vibration. Ideally, cost and incorporating rates of proit and overhead ex pensesincluding fuel econom y com parisons should be m ade on the s basi warranties, transport, and retailing. A lthough lear ning and of no com prom ise for the consum er. Often there dif-are technological progress never stop, R P Es are intende d to repferences of opinion about what design and engineering resent costs after an initial period of rapid cost reduction that changes m ay be req uired to ensure no com prom ise for 2 The com m ittee uses the term results from learning by doing. the consum er. This, in turn, leads to differinglsbil of su b stantial l y l earned as opposed to fu l l y l earned to convey m aterials to be costed out, which leads to signiica nt that cost reductions due to increasing volum es m continue ay differences in increm ental R P E estim ates. to occur. R P Es are not intended to replicate therk m eta price • Learning b y do ing , scal e eco no mies, and co . mp etitio n of a speciic vehicle or a speciic optional feature at a speciic W hen new technologies are irst introduced and only tim e. The m ark et price of a particular vehicleparticular at a one or two suppliers ex ist, costs are typically hig her tim e depends on m any factors ( e. g. , m ark et trends, m ark eting than they will be in the long run due to lack of scale strategies, proit opportunities, business cycles, em t porary econom ies, as- yet- unrealiz ed learning by doing, and shortages or surpluses) other than the cost of m anu facturing lim ited com petition. These transitional costs can e b and retailing a vehicle or any given com ponent. is It not apim portant to m anufacturers’ bottom lines and should propriate to base a long- term policy such as fuelconom e y be considered. H owever, nearly all cost estim ates re a standards on short- run conditions or special circumstances. developed assum ing long- run, high- volum e, average The R P E concept, unfortunately, is not easy to appl y. econom ic conditions. Typical assum ptions include It raises a num ber of dificult q uestions about appr opriate ( 1 ) high volum e, ( 2 ) substantially learned com poprem ises and assum ptions and reliable sources ofta.da It nent costs, and ( 3 ) com petition provided by att leas freq uently relies on the application of m ark upors, fact which three global suppliers available to each m anufactur er could vary depending on the nature of the technology and the ( M artec Group, Inc. , 2 0 0 8 a, slide 3 ) . Us- nder these a basis for the original cost estim ate. W hen an R ark P Eupm sum ptions, it is not appropriate to em ploy traditio nal factor is used, the deinition of the cost to whichit applies is learning curves to predict future reductions in cost as critical. M uch of the disagreem ent over R P Eiers m can ultipl production ex perience increases. H owever, if cost be traced to inconsistent deinition of the cost to be m ark ed estim ates are for novel technology and do not relec t up. The following are k ey prem ises of the com m’s ittee learning by doing, then the application of learning application of the R P E m ethod. curves as well as the estim ation of scale econom ies m ay be appropriate. The use of such m ethods intro• Incremental R P. The E relevant m easure of cost is the duces substantial uncertainty, however, since thereare change in R P E in com parison to an eq uivalent evehicl no proven m ethods for predicting the am ount of cost without the particular fuel econom y technology. Me or reduction that a new technology will achieve. often than not, a fuel econom y technology replaces • No rmal p ro du ct cyAcl ses. a general rule, prem ises inan ex isting technology. F or ex am ple, a 6 - speed auto clude norm al redesign and product turnover schedule s. m atic transm ission replaces a 5 - speed, a com n-pressio A ccelerated rates of im plem entation can increase sts co by decreasing am ortiz ation periods and by dem anding 2 L earning by doing represents the increase in produ m ore engineering and design resources than are avai lctivity and decrease in able. P roduct cycles are discussed in Chapter 7 . cost that occurs during a technology’s lifetim e as a result of m anufacturers’ gaining ex perience in producing the technology. The im pacts of learning on • P u rchased co mp o nents versu s in- ho u se manu factu re. costs can be represented as a volum e- based learning where costs reductions Costs can be estim ated at different stages in the m anuoccur with increasing production levels or as a time- based learning where facturing process. M anufacturing cost estim ates- gen cost reductions occur over tim e.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 6

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

erally do not include warranty, proit, transportation, ix ed or overhead costs scale with variable costs isa k ey area and retailing costs, and m ay not include overheadr o of uncertainty. research and developm ent.Other estim ates are based A lthough m any com ponents are m anufactured in- house on the prices that original eq uipm ent m anufactur- by OEM s, it is useful to distinguish between com ent pon ers ( OEM s) would pay a Tier 1 supplier for a fully and vehicle assem bly costs, because m any m anufactur ers 3 These estim ates include m anufactured com ponent. purchase 5 0 percent or m ore of a vehicle’s com ts ponen from the supplier’s overhead, proit, and R & D costs, not but suppliers. Transaction prices and price estim atesrom f Tier 1 costs incurred by the OEM . R P Es attem pt to estim and ate Tier 2 suppliers are a m ajor source of inform ion at on the the fully m ark ed- up cost to the ultim ate vehicle r- pu costs of fuel econom y technologies. chaser. A k ey issue for cost estim ates based on r 1Tie V ariable m anufacturing costs of com ponents include m asupplier costs is the appropriate m ark up to R P isE. Th terials, labor, and direct labor burden ( Table 3 .. 1V ) ariable will depend on the degree to which the part req uires m anufacturing costs are som etim es referreddirect to as manengineering and design changes to be integrated into u factu ring co although sts, when this term is used it typically the vehicle, and other factors. includes the depreciation and am ortiz ation of m acturing anuf • Al l o catio n o f o verhead co S pecific sts. changes in eq uipm ent. F ix ed costs of com ponent m anufacturing nclude i vehicle technology and design m ay affect som e of tooling and facilities depreciation and am ortiz atio n associan OEM ’s costs of doing business and not others. A ated with capital investm ents, m anufacturing overhe ad ( e. g. , reduction in engine friction, for ex am ple, m ight t no R & D , engineering, warranty, etc. ) , and proit turn( to or re affect advertising budgets or transportation costs. To capital) . U nfortunately, term inology freq uently fers dif from date there is a very lim ited understanding of howot one study to another. Total m anufacturing costs (riable va determ ine which costs of doing business are affecte d plus ix ed) are eq uivalent to the price that a Tier 1 supplier by each individual technology and how to develop would charge an OEM for a inished com ponent, ready for technology- speciic m ark ups ( e. g. , R ogoz hin et installation. al. , 2 0 0 9 ) . In theory, this approach has the potential o t OEM or assem bly costs include the variable costs of yield the m ost accurate results. H owever, in practi ce, m aterials, labor, and direct labor burden for vehic le assem unam biguous attribution of costs to speciic vehicle com ponents is dificult. F or ex am ple, despite ex tensive reliability testing, it is not possible to predict with certainty what im pact a technology or design change TA BL E 3 . 1 Com ponents of V ehicle R etail P rice will have on warranty costs. F urtherm ore, there are Eq uivalent ( L ong- R un A verage Cost) signiicant cost com ponents that cannot logically be Com ponent M anufacturing ( S ubassem bly) allocated to any individual com ponent. A m ong theseV ariable com ponent m anufacturing costs are the m aintenance of a dealer network and adverti sM aterials ing. Y et, these costs m ust be paid. The R P E m ethod L abor D irect labor burden assum es that such costs should be allocated in prop orF ix ed com ponent m anufacturing costs tion to the com ponent’s cost and that overall overh ead Tooling and facilities depreciation and am ortiz on ati costs will increase in proportion to total vehicle cost. R & D This will not necessarily produce the m ost accurate Engineering estim ate for each individual item but is consistent with W arranty the goal of estim ating long- run average costs. Other overhead P roit

COMPONENTS OF COST

V ehicle A ssem bly and M ark eting V ariable costs

A lthough different studies describe and group the om c A ssem bly m aterials A ssem bly labor ponents of the retail price eq uivalent ( long- runerage av cost) D irect labor burden in different ways, there are four fundam ental comnents: po F ix ed costs ( 1 ) the variable costs of m anufacturing com ponents, ( 2 ) ix ed Tooling and facilities depreciation and am costs of m anufacturing com ponents, ( 3 ) variable ts ofcos W arranty vehicle assem bly, and ( 4 ) ix ed costs of vehicle em ass bly R & D Engineering and sale. The distinction between variable and ix edcosts is W arranty not a sharp one, because m any “ix ed” costs scalesom to e Other overhead ex tent with production volum e. In fact, the degree to which 3 Tier

1 suppliers contract directly with OEM s, wher eas Tier 2 suppliers contract with Tier 1 suppliers.

ortiz on ati

Transportation M ark eting and advertising D ealer costs and proit Original eq uipm ent m anufacturer proit

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

COST ESTIMATION

bly. F ix ed costs include facilities and tooling dep reciation and am ortiz ation, warranty, R & D , engineering, tising,adver dealer ex penses and proit, transportation, and OEM return on investm ent ( proit) . The sum total of all costs, divided by the Tier 1 supplier price ( or eq uivalent) , is dcalle the R P E m ark up. The costs of inputs to the production process can vary over tim e. S om e k ey com ponents, such as electrical system s, em issions controls, and hybrid vehicle batter ies, use relatively ex pensive m etals whose prices can be vol atile, signiicantly im pacting m anufacturing costs. Theces priof m any of these m etals increased dram atically prior o thet global recession beginning in 2 0 0 8 , but have since returned to previous levels. M ost publicly available estimes at of technology costs do not ex plicitly relect uncertainties about future com m odity prices.

2 7

ex perience future cost reductions relative to curre nt estim ates through learning by doing. Technologies such as cylinder deactivation, cam less valve trains, gasoline direct injection with lean burn, turbocharging with engine downsiz in g, and hybrid system s from stop- start to full hybrids plugand in hybrids were all assum ed to have progress ratios of 0 . 8 ( i. e. , a doubling of cum ulative production would reduce cost s by 2 0 percent) . D iesel em issions control system s were um ass ed to have sm aller progress ratios of 0 . 9 ( EP A , ble 2 04 0. 28 -a,3 Ta ). If supplier cost estim ates truly represent fully arned le costs ( at full scale econom ies) , then there is ustiication no j for assum ing future learning by doing. The cost est im ates m ade by M artec for the Northeast S tates Center a Clean for A ir F uture ( NES CCA F ) , for ex am ple, werere-intended to lect cost reductions by learning that would occur over the period 2 0 0 9 - 2 0 1 1 . In its study for the A utom lliance obile of M anufacturers, M artec intended that its cost estim tes relect a full scale econom ies and full learning: “M artec ciied spe FACTORS AFFECTING COSTS OVER TIME AND an ex trem ely high annual volum e target [ 5 0 0ts, per 0 0 0 uni ACROSS MANUFACTURERS year] speciically to drive respondents to report m ure, at Cost estim ates for fuel econom y technologies arepi-ty forward costs ex pected in the future with the im pac t of learncally presented as a single point estim ate or as range. a In ing fully relected” ( M artec Group, Inc. , 2 0 07 8) .b,But p. fact, costs will vary over tim e and even across mufacturers an M artec identiies two sources of learning: ( 1 ) ovem im pr ent owing to technological progress, ex perience ( learni ng by in m anufacturing productivity, largely as a result of prodoing) , prices of com m odities, labor and capital, and the duction volum e; and ( 2 ) changes in system design. artec M nature of the vehicles m anufactured. considered the latter to be technological innovations that would change the system architecture and thus theechnolt ogy itself, req uiring new cost estim ates. Thus, learning the Economies of Scale considered by M artec in its estim ates is based he on belief t S cale econom ies describe the tendency for averageanum that the Tier 1 and Tier 2 suppliers would im plicit ly include facturing costs to decrease with increasing volum e, as ix ed learning effects of the irst type in their high- volum e cost costs are distributed over a greater num ber of unit s produced. estim ates, and would ex clude learning of the second type. The autom obile industry is characteriz ed by large conom e ies In its 2 0 1 1 corporate average fuel econom y ( CA ule- F E) r of scale. A lthough sources differ, full scale econo m ies are m ak ing, the NH TS A recogniz ed two types of by learning generally considered to be reached at between 1 0 00 ,00 and doing: “volum e- based” learning and “tim e- based” rning. lea 5 0 0 , 0 0 0 units per year. M artec Group, Inc. for (ex2 0- 0 8Neither a) , is based on cum ulative production, as is m ch of u the am ple, asserts that production eficiencies are m max izi ed at literature on learning by doing. D OT/ NH TS A (. 21 08 05 9) , p 2 5 0 , 0 0 0 to 3 0 0 , 0 0 0 units. H onda cited a m ax im um that eficiency judged a irst cycle of volum e- based learningould w of 3 0 0 , 0 0 0 units in its com m ents to the D 2OT/ 0 NH 0 9 ,TS A at( a volum e of 3 0 0 , 0 0 0 units per year occur t costs and tha p. 1 8 5 ) . would be reduced by 2 0 percent over low- volum m e esti ates. A second learning threshold was set at 6 0 0 , 0 s0 per 0 unit year, at which point a second cost reduction of 2 0percent Technological Progress and Learning by Doing was tak en. No further volum e- based learning wasum ass ed. A lthough cost estim ates are generally prem isedullon f The NH TS A applied this procedure to only threenolotech scale econom ies and fully learned technologies, bot h the gies in its 2 0 1 1 rule: integrated starter generator , two- m ode EP A and the NH TS A believe that not all Tierier 1 or suppl hybrid, and plug- in hybrid. piece cost estim ates represent fully learned techno logy costs. D OT/ NH TS A ( 2 0 0 9 , p. 1 8 8 ) also applies tim e- b In their view, learning curves should be applied for the m ore year- over- year learning by doing to widely availabl e, highnovel technologies not in widespread use today.4 The EP A volum e, m ature technologies. Either tim e- based olum or velisted 1 6 advanced technologies that, in its judgm nt, would e based learning, but not both, is applied to a parti cular technology. Tim e- based learning is applied at the rate3ofpercent per 4 The EP A year in the second and all subseq uent years of a te chnology’s generally does not use typical continuous learning curves but instead stepwise learning as a function of tim , erather than cum ulative application. production. U sually, costs are assum ed to decrease by 1 0 percent after the The use of learning curves poses a dilem m a. Onone the irst year of production, and by another 1 0 percent after the second year, hand, there is no rigorous m ethod for determ ining ow h m uch and then to rem ain constant.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 8

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

and how rapidly a speciic technology’s costs can be reduced TA BL E 3 . 2 V ehicle Classiication by the National by learning by doing.5 On the other hand, the phenom enon H ighway Trafic S afety A dm inistration of learning by doing is widely and generally observed in the P assenger Cars m anufacturing of new technologies ( e. g. , W ene, ) . 2This 0 0 0 S ubcom pact does not m ean that no learning should be assum ed. ather, R S ubcom pact perform ance learning curves should be applied cautiously and should Com pact relect average rates of learning based on em pirical evidence Com pact perform ance M idsiz e from the m otor vehicle industry. Ex pert judgm ould ent be sh M idsiz e perform ance used to determ ine the potential for learning, depen ding on L arge the nature of the technology in q uestion. L arge perform ance L ight Truck s

Vehicle Type or Class

M inivans

S m all S U V / pick up/ van The costs of fuel econom y technology also vary acro ss M idsiz e S U V / pick up/ van vehicle classes. To a large ex tent this is a functi on of vehicle L arge S U V / pick up/ van siz e and power. F or ex am ple, an eight- cylinder ne has engi twice as m any valves as a four- cylinder, and so the costs of valve train technologies will be higher. W hen techn ologies, such as turbocharging, increase the power output per unit ( m inivans) and footprint siz e ( sport utility vehicl es [ S U V s] , of displacem ent and thereby enable engine downsizginat pick ups, and vans) . constant perform ance, the starting cylinder countanc affect A lthough classiication can im prove the accuracycost of the options for downsiz ing. In general, an eight-linder cy estim ates, there is no perfect classiication system , and there engine can be replaced by a sm aller six - cylindergine en of will always be som e heterogeneity within a class. eq uivalent perform ance without additional costs for m itigating vibration. D ownsiz ing a four- cylinder to aethre cylinder METHODS OF ESTIMATING COSTS would req uire signiicant m odiications to offset reased inc vibration, and this m ight even rule out reducingethcylinder A s a generaliz ation, there are two basic m ethods cost of count. S ince m ost of the cost savings from downsiz ng accrue i estim ation. The irst and m ost com m on is to obtain stie from reducing the num ber of cylinders, technologies that m ates of the selling prices of m anufactured com nts. pone enable engine downsiz ing will be relatively m orepensive ex The second is to tear down a technology into its m sto basic for four- cylinder engines. S ince different vehicle classes m aterials and m anufacturing processes and to constr uct a have different distributions of cylinder counts, the costs of bottom - up estim ate by costing out m aterials, and labor, certain technologies should be class- dependent. A another s capital costs for every step. Both m ethods ultim lyate rely ex am ple, the cost of a 1 percent weight reduction y m b aterial heavily on the ex pertise and the absence of bias onthe cost substitution will depend on the initial m ass of the vehicle. estim ator’s part. National R esearch Council ( 2 0 0 2 ) did not vary olo-techn gy costs by vehicle class. The NH TS A ’s V olpe smalgoodel’ Estimation Using Supplier Prices for Components, or rithm , however, operates at the level of m ak e,l, mengine, ode “Piece Costs” and transm ission coniguration. S om e technologys are cost scaled to the speciic attributes of each vehicle. Other costs The supplier price m ethod relies on com paring an- es are class- dependent. In its inal rule for 2 0 1 1 /, NH D OT TS A tim ate of the price that a Tier 1 com ponent m turer anufac ( 2 0 0 9 , p. 1 6 5 ) speciied eight passenger and car classes four would charge an OEM for a reference com ponent toestian light truck classes ( Table 3 . 2 ) . P assenger cars e divided wer m ate of the price that it would charge for an alter native that into siz e classes on the basis of their footprint.Each class delivered reduced fuel consum ption. In the past,form in ation was divided into a standard and high- perform anceass cl on on the prices that m anufacturers pay to Tier 1 supp liers for the basis of class- speciic cut- points determ ineding us ex pert com ponents has com e from a variety of sources, uding incl judgm ent. This relects the NH TS A ’s view thatition in add to the following: siz e, perform ance is the k ey factor determ ining differences in technology applicability and cost. The classiication of light • The NR C ( 2 0 0 2 ) report on the CA F E standards; truck s was based on structural and design considerations • The NES CCA F ( 2 0 0 4 ) study on reducing light- duty vehicle greenhouse gas em issions; 5 Not only the progress ratio, but also the assum ed • The California A ir R esources Board study in supp ort initial cum ulative production ( or threshold volum e) strongly inluences estim ated future of its greenhouse gas regulations; cost reductions. Num erous after- the- fact estim sation of progress ratios are • The study by Energy and Environm ental A nalysis, Inc. available. H owever, in general, there is no scienti ic m ethod for deciding ( EEA , 2 0 0 6 ) for Transport Canada; on these param eters ex ante.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

COST ESTIMATION

• Conidential data subm itted by m anufacturers he to t NH TS A in advance of rulem ak ings; and • Conidential data shared by m anufacturers in m ings eet with the NH TS A and the EP A in 2 0 0 7 .

2 9

and ( 2 ) ix ed or burden costs. Estim ating costs he conto t sum er ( analogous to the retail price eq uivalent)q uires re additionally estim ating the OEM ’s am ortiz edascosts, well as other costs and proit. D ealers’ costs are added to the m anufacturer’s cost plus proit to obtain the consum er’s Com ponent cost estim ates can be obtained from sdiscu cost ( F igure 3 . 1 ) . A s the NH TS A report o point is careful t sions with suppliers or OEM s, from published report s, or by out, estim ating costs “is not an ex act science” rather but one com paring the prices of vehicles with and withouthet com strongly dependent on the ex pertise and judgm ent the of ponent in q uestion ( D uleep, 2 0 0 8 ) , bearing thatincosts m ind estim ators at every step. and m ark et prices m ay differ signiicantly. The NH A also TS The teardown m ethod was applied by K olwich ( 2 0o 0 9 ) t receives cost estim ates in the form of conidential data subestim ate the increm ental m anufacturing cost ofwnsiz a do ed m itted by m anufacturers. D epending on how fuelom econy 1 . 6 - liter, four- cylinder, stoichiom etric direct injection, turbotechnologies are deined, estim ates for m ore than e com on charged engine versus a 2 . 4 - liter, four- cylinder, aturally n ponent m ay be involved. Given a supplier price esti m ate, a aspirated base engine. The study did not attem pt estim to ate m ark up factor is applied to estim ate the R P gle E. m A ark sin up the m ark up from m anufacturing costs to R P E.theR ather, factor is often used for all com ponents, but differ ent m ark ups cost estim ated is eq uivalent to the price that aerTi1 supplier m ay be used according to the nature of the com ponen t. The would charge an OEM for the fully m anufactured engi ne. k ey issues are, therefore, the accuracy of the supp lier price U nit costs are com posed of direct m anufacturing ts (cos m ateestim ates and the accuracy of the m ark up factor( s) . rial + labor + ix ed m anufacturing costs) + “m costs” ark up F irst at the req uest of NES CCA F ( 2 0 0 4 )theand later ( scrap at + overhead + proit) + pack aging costse( 3F . igur 2 ). req uest of the A lliance of A utom obile M anufacturers , M artec M anufacturing costs are estim ated in a series of ghly hi Group, Inc. ( 2 0 0 8 b) estim ated the variable factur( or m anudetailed steps based on what is learned in disassembling the ing) costs of fuel econom y technologies based onethbill of technology. Both the new and the base technologiesm ust be m aterials ( BOM ) req uired. Thematerial term s as used in torn down and costed in order to estim ate the diffe rence in the M artec studies refers to m anufactured com ponent s supcost. F irst, the technology to be evaluated is iden tiied and plied by Tier 1 and Tier 2 suppliers. The directdanindirect deined. Nex t, candidate vehicles for teardown aredentiied i changes in vehicle com ponents associated with a par ticular ( this lim its the analysis to technologies alreadyn iproductechnology were determ ined in discussions with engi neering tion) . A pre- teardown, high- level bill of m aterials ( consistconsultants and OEM engineers. The Tier 1 and Tier 2 suping of subsystem s and com ponents) is then created, subject pliers were the prim ary sources of inform ation on he costs t to am endm ent, as discoveries m ight be m ade during he t of m anufactured com ponents req uired to im plem e fuel ent th teardown process. A t that point, the actual teardow n process econom y increases ( M artec Group, Inc. , 2 0 0. 8 b, p. 7 begins. ) D uring the teardown, all of the processesecessary n for assem bly are identiied and recorded, and every com ponent and the m aterial of which it is m ade are ident iied. The Teardown or Bottom-Up Estimation data generated in the disassem bly are then reviewedby a A change in the design and content of a vehicle ind uces team of ex perts. F ollowing the review, the com tsponen are changes in the m aterials of which it is m ade, the uantity q torn down and assem bly processes are identiied, as is each and types of labor req uired to construct it, and ch anges in the and every piece of each com ponent. A work sheethen is t capital eq uipm ent needed to m anufacture it. S tim uch es ates constructed for all parts, containing all cost elements. P arts not only are tim e- consum ing but also req uire analys ts with with high or unex pected cost results are double- che ck ed, a thorough k nowledge of and ex perience with automiveot and then entered into a inal spreadsheet in which they are m anufacturing processes. totaled and form atted. Bottom - up cost estim ation m ethods have been used by the Once m anufacturing costs have been estim ated, akmupar NH TS A for assessing the im pacts of safety regulatio ns. F or relecting all other costs of doing business is typically applied ex am ple, in a study of air bag costs, an NH TS ractor A cont to estim ate the long- run cost that consum ers will ave hto used a teardown m ethod to identify all com ponents f 1o 3 pay. A pplying this m ark up was outside the scope theof F EV ex isting air bag system s. This study ( L udtk esociates, and A s ( 2 0 0 9 ) study but was included in the L udtk eociates and A ss 2 0 0 4 ) is described in A ppendix F . The contractor alyz ed an ( 2 0 0 4 ) study. Estim ates of the consum er’surtain cost of c each part or assem bly and identiied each m anufactur ing air bag system s installed in ive different vehiclesfrom the process req uired for fabrication, from raw m aterial to inL udtk e and A ssociates study are shown in TableA3 .lthough 3 . ished product. The analysis identiied parts purchased from costs vary, it is clear that L udtk e and A ssociates used the sam e suppliers as well as parts m ade in- house. P rocess ngineers e m ark up factors for Tier 1 m anufacturers’ m ark er their ups ov and cost estim ators then carried out a process and cost analydirect costs ( 2 4 percent) , OEM m ark ups ( 3, 6andpercent) sis for each part and assem bly. Two costs were deve loped: dealer m ark ups ( 1 1 percent) . These m ark nups m result ulti- i ( 1 ) variable costs associated with the actual m acturing anuf pliers for the consum er’s cost over the Tier 1 supp lier’s cost of

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

3 0

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

F IGU R E 3 . 1

D eterm ination of m anufacturing m and er cost. consu OU S R CE: L udtk e and A ssociates ( 2 0 0 4 ) , p. B- 1 0 .

=

Net Component/Assembly Cost Impact To OEM

Material

+ Raw Material

In Process S crap

Purch ased Parts

+

D irect L abor

Ind irect L abor

L abor Maintenance, Repair, Oth er

+ Manufacturing Ov erh ead /B urd en

F IGU R E 3 . 2

Fringe

Mark -up Cost

=

=

Total Manufacturing Cost

End Item S crap

+ S ell, G eneral & Ad ministrativ e Costs

+ Profit

+ Engineering, D esign and Testing/R& D

U nit cost m odel. S OU R CE:) F( EV F EV , Inc. . com ( 2 )0, 0F 9igure 5 .

+

Packaging Cost

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

3 1

COST ESTIMATION

TA BL E 3 . 3

Estim ated Consum er Cost ( 2 0 r0 Installed 3 dollars) A irfoBag S ystem s and M ark ups

Item

V W

M aterial D irect labor D irect labor burden Tier 1 m ark up M anufacturer m ark up D ealer m ark up Consum er’s cost V ariable cost V ariable m anufacturing cost M ark up Tier 1 cost M ark up variable m anufacturing cost Tier 1 m ark up OEM m ark up D ealer m ark up

J etta

Toyota Cam ry

M ercurya M J onterey eep Grand Cherok ee

Cadillac CTS

$ 3 0 .0 4 $ 1 1 .1 1 $ 2 2 .5 9 $ 1 5 .4 0 $ 2 8 .4 9 $ 1 1 .8 4 $ 1 1 9 .4 7 $ 6 3 .7 4 $ 7 9 .1 4 1 .5 1 1 .8 7

$ 2 7 .4 5 $ 2 0 .5 4 $ 3 4 .4 0 $ 1 9 .8 9 $ 3 6 .8 2 $ 1 5 .3 0 $ 1 5 4 .4 0 $ 8 2 .3 9 $ 1 0 2 .2 8 1 .5 1 1 .8 7

$ 4 8 .4 6 $ 1 6 .5 4 $ 2 4 .6 1 $ 2 1 .9 3 $ 4 0 .1 5 $ 1 6 .6 9 $ 1 6 8 .3 8 $ 8 9 .6 1 $ 1 1 1. 0. 57 4 1 .5 1 1 .8 8

$ 6 9 .8 8 $ 3 7 .6 2 $ 5 5 .9 1 $ 3 9 .6 6 $ 7 3 .1 1 $ 3 0 .3 8 $ 3 0 6 .5 5 $ 1 6 3 .4 1 $$ 12 10 93 . 2 5 1 .5 1 1 . 8 .88 7

2 4 .2 % 3 6 .0 % 1 1 .0 %

2 4 .1 % 3 6 .0 % 1 1 .0 %

2 4 .5 % 3 6 .0 % 1 1 .0 %

2 4 .3 % 3 6 .0 % 1 1 .0 %

$ 5 4 .4 $ 1 7 .6 8 $ 2 3 .9 3 $ 2 3 . $ 4 2 . $ 1 7 . $ 1 8 $ 9 6 .0 1 .5 1 1

2 4 .2 % 3 6 .0 % 1 1 .0 %

NOTE: Original eq uipm ent m anufacturer ( OEM ) turing m anufac costs ( 2 0 0 3 $ ) per vehicle—head protection r bag system ai s ( curtain- type system without a torso airbag already installed in vehicle) . aCost estim ates for the M ercury M onterey are substan tially higher than those for the other vehicles. L dtk u e and A ssociates ( 2 0 0 4 ) do not offer an ex planation for the design differences that account for the higher cost. S OU R CE: L udtk e and A ssociates ( 2 0 0 4 ) .

1 . 5 1 ( ×1 1. 3. 16 1 = 1 . 5 1 ) , and for the consum er’s cost overThe theF EV teardown study ( F EV , 2 0 0 9 ; K olwich, l2 0 0 direct variable costs of m anufacturing Total ( “ M anufacturing lows total m anufacturing costs to be brok en down engine by Costs” m inus “M anufacturing Overhead Burden” inFtheEV subsystem as well as cost com ponent. F igure 3 ws . 3thesho [ 2 0 0 9 ] study; see F igure 3 . 2 above) the com f 1 . 8ponent 7 increm o ental m anufacturing costs by cost com ponent. The ( 1 . 2× 14 . 3×61 . 1 1 = 1 . 8 7 ) . The costs shown in Table 3largest . 3 aresingle com ponent of the $ 5 3 7 . 7 0 total terialis m a in 2 0 0 3 dollars and assum e a m anufacturing2scale 5 0of, 0 0 0( $ 2 1 8 . 8 2 ) , followed by m anufacturing burden 4 ) ,( $ 1 5 4 . units per year for the air bags. labor ( $ 7 2 . 5 8 ) , corporate overhead ( $ 3 (3 $. 93 63 ). 1, proit 2 ), W hile L udtk e and A ssociates ( 2 0 0 4 ) usetor a m arkengineering up fac and R & D ( $ 1 2 . 3 6 ) , and scrap he ( $ 1 1 . 7 2 of 1 . 2 4 for direct m anufacturing costs, K olwich 0 9 )( 2uses 0 total m ark up on m anufacturing costs is just over percent. 2 0 m ark up factors ranging from 1 0 . 3 percent torcent, 1 7 . 7 pe F igure 3 . 4 shows the sam e total cost brok en down engine by depending on the com plex ity of the com ponent ( Table 3 . 4 ) . subsystem . By far the largest com ponents are the duction in Note that the K olwich rates do not include m anufact uring air charging system ( $ 2 5 8 . 8 9 ) and the fuel n system inductio overhead whereas the L udtk e rates do, and thus the form er ( $ 1 0 7 . 3 2 ) . Cost savings occur in counterbalance 5 . 9 5( $) 3 should be higher. and intak e system s ( $ 1 2 . 7 3 ) .

TA BL E 3 . 4 Total M anufacturing Cost M ark up Tier R 1ates and forTier 2 / 3 S uppliers

P rim ary M anufacturing Eq uipm ent Group Tier 2 / 3 —large siz e, high com plex ity Tier 2 / 3 —m edium siz e, m oderate com plex ity Tier 2 / 3 —sm all siz e, low com plex ity Tier 1 Tier 1 Tier 1 Tier 1

com plete system / subsystem supplier ( system ubsystem/ s integrator) high- com plex ity- com ponent supplier m oderate- com plex ity- com ponent supplier low- com plex ity- com ponent supplier

S OU R CE: K olwich ( 2 0 0 9 ) , Table 2 .

End Item S crap M ark up (% ) 0 .7 0 .3

S G& A M ark up (% ) 7 .0 0 .5 6 .0

0 .7

P roit M ark up (% ) 8 .0 6 .5 4 .0

7 .0 0 .7 0 .5 0 .3

ED & T M ark up (% )

2 .0 .0 6 .0 1 4 . 01 0 .0

8 .0 7 .0 6 6. 5. 0 6 .0

Total M ark up (% )

8 ..00 2 .5 4 .00

1 7 .7 1 0 .3

6 .0 2 1 .7 14 9 . 7 1 5 .5 111. . 3

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ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

F IGU R E 3 . 3 Increm ental cost of turbocharged, z ed, downsi gasoline direct- injection I4 engine brok en dow n by cost category. SOU R CE: K olwich ( 2 0 0 9 ) , F igure 1 9 .

F IGU R E 3 . 4 Increm ental cost of turbocharged, z ed, downsi gasoline direct- injection I4 engine brok enndow by engine subsystem . S OU R CE: K olwich ( 2 0 0 9 ) , F igure 1 9 .

RETAIL PRICE EQUIVALENT MARKUP FACTORS

which m ay or m ay not induce other changes in thestco of m anufacturing. These integration costs can be subst antial for M ark up factors relating com ponent costs to R P E add m ajor com ponents, such as engines, or when, asore is often m signiicantly to the estim ated costs of autom otive echnolot the case than not, m any changes are m ade sim ultaneo usly. gies and are the subject of continuing controversy. The cost There are also indirect costs for research and developm ent, of m ak ing and selling light- duty vehicles is not m liited to adm inistrative overhead, warranties, and m ark and eting adthe m anufacture of com ponents and their assem bly. ven E vertising. V ehicles m ust be transported to dealers who have for a single technological or design change, cost im pacts are their own labor, m aterial, and capital costs. Af these ll o addigenerally not lim ited to the com ponent that is chan ged. Engitional costs are represented by R P E m ark up factors. neering ex pertise m ust be supplied to design these changes,

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

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COST ESTIMATION

Existing RPE Markup Factors

OEM was also supported by Bussm ann ( 2 0 0 8 )d, awho cite 2 0 0 3 study of the global autom otive industry byinsey M cK F or the autom obile industry, there is a reasonable consenGlobal Institute that produced a m ark up factor of. 02 8 , and sus on the ratio of total costs of doing business to the cost his own analysis of Chrysler data for 2 0 0 3 - 2 0t pro0 4 tha of fully m anufactured com ponents ( the price that Tier a 1 duced factors of 1 . 9 6 to 1 . 9 7 . Inform ation bysupplied EEA , supplier would charge an OEM ) . This average R P kE up m ar Inc. , to the com m ittee ( D uleep, 2 0 0 8 ) rim m ark pliesup highe factor is approx im ately 1 . 5 , according to the able avail evifactors: 2 . 2 2 to 2 . 5 1 for the m ark up over costs variable and dence, reviewed in detail in A ppendix F of thisort. repP art 1 . 6 5 to 1 . 7 3 for the m ark up over Tier 1sts.supplier co of the disagreem ent over the siz e of the R P E m factor ark up A verage R P E factors can be inferred by costing all out arises from the difference between the variable cos ts versus the com ponents of a vehicle, sum m ing those costs obtain to the variable plus ix ed costs of a m anufactured com onent. p an estim ate of OEM Tier 1 costs or fully burdened n- house i A n appropriate R P E m ark up over the variableect) ( or dir m anufacturing costs, and then dividing the sum into the costs of a com ponent is approx im ately 2 . 0 ( Bussm and ann selling price of a vehicle. The com m ittee contracte d with W hinihan, 2 0 0 9 ) . P art of the disagreem ent er the arises ov IBIS A ssociates ( 2 0 0 8 ) to conduct such anfor analysis two dificulty of attributing indirect and other ix ed costs to a high- selling m odel- year 2 0 0 9 vehicles: the Hcord onda A c particular vehicle com ponent. sedan and the F ord F - 1 5 0 pick up truck . F ora, the H ond Every fuel econom y technology does not affect ix or ed the R P E m ultipliers were 1 . 3 9 to m ark et price transaction indirect costs in the sam e way. S om e costs m ffected ay be aby and 1 . 4 9 to m anufacturer’s suggested retail price M S( R P ) . engineering and design changes to decrease fuel consum pThe m ultiplier to dealer invoice cost is 1 . 3 5 ying , im that pl tion; others m ay not. This can have a very large pact im on dealer costs, including proit, am ount to about 4rcent pe of the appropriate R P E of a given fuel econom y technol ogy. m anufacturing costs, not considering any dealer inc entives S om e studies use a single, average R P E m arkr (up e. facto g. , provided by OEM s. F or the F ord F - 1 5 0 , thepliers R P E m ulti NR C, 2 0 0 2 ; A lbu, 2 0 0 8 ; D OT/ NH TS rsA , 2 0 0 9 ) , while othe were 1 . 5 2 for m ark et price and 1 . 5 4 for M S R P . The m attem pt to tailor the m ark up to the nature ofechnology the t factor for dealer invoice is 1 . 4 3 , im plying aler that costs de ( R ogoz hin et al. , 2 0 0 9 ; D uleep, 2 0 0 8of )how . The problem and proit am ount to about 9 percent of total m anufa cturing best to attribute indirect and ix ed costs to a speciic change costs, not including any possible OEM incentives dealers. to in vehicle technology rem ains unresolved. Ex isting estim ates of the R P E m ark up factor ilar are sim when interpreted consistently. V yas et al. ( 2 0 om 0 0 pared ) c The EPA Study on RPE Factors and Indirect Cost their own m ark up factors to estim ates developedEEA by , Multipliers Inc. , and Chrysler. U nfortunately, differenceshe in deinit tions of categories of costs preclude precise com pa risons. Concerns with the Existing RPE Method V yas et al. concluded that an appropriate m ark ctor up fa Objections have been raised with respect to the use of a over the variable costs of m anufacturing a m otorhicle ve was single R P E m ark up factor for com ponents m anufacture d by 2 . 0 . The V yas et al. ( 2 0 0 0 ) report also sum the cost m ariz ed Tier 1 suppliers and sold to OEM s. The EP A has tedpoin out m ethodology used by EEA , Inc. , in a study for the ficeO that not all technologies will affect indirect costs eq ually, and of Technology A ssessm ent ( OTA , 1 9 9 5 ) . 2V0 yas 0 0et) al. ( it has proposed to investigate technology- speciic mark ups, concluded that the m ark up over variable m anufacturi ng by attem pting to identify only those indirect costsactually costs used in that study was 2 . 1 4 , while the m over ark up affected by each technology ( EP A , 2 0 0 8 b) lar . In vein, a sim i outsourced parts ( e. g. , purchased from a Tier 1plier) sup was the im portance of “integration costs” has been cite d as a fac1 . 5 6 ( Table 3 . 5 ) . tor that would justify different m ark up factors for different A m ark up factor of 1 . 5 was also used by the NH TS A technologies ( D uleep, 2 06 Because 0 8 ) . a vehicle is a system , ( 2 0 0 9 , p. 1 7 3 ) in its inal fuel econom 1y rule 1 . A for 2 0 it is alm ost always the case that the design of one part affects som ewhat lower R P E m ark up factor of 1 . 4 was theused by others. M anufacturers cannot sim ply buy a listarts of pand NR C ( 2 0 0 2 ) and A lbu ( 2 0 0 8 ) , while thea EP A has used m ark up of 1 . 2 6 ( EP A , 2 0 0 8 a) . 6 D uleep ( 2 0 0 8 ) recom m ends using different ctors m for arkdifferup fa The use of a m ark up of approx im ately 2 overect the dir ent k inds of com ponents to account for differences in the cost of integrating m anufacturing costs of parts m anufactured in- house by an com ponents into the overall vehicle design. F ortspar purchased from Tier 1 TA BL E 3 . 5

Com parison of M ark up F actors

M ark up F actor for In- house com ponents Outsourced com ponents

A NL 2 .0 0 1 .5 0

S OU R CE: V yas et al. ( 2 0 0 0 ) .

Borroni- Bird 2 .0 5 1 .5 6

suppliers, D uleep recom m ends a range of m ark up factors 1 . 4from 5 to 1 . 7 , depending chiely on integration costs. A s an ex am e, Dpl uleep presented to the com m ittee an estim ated m ark up factor of r injector, 1 . 7 2 pum fo p, and rail costs for a stoichiom etric GD I engine. This isheathigh t end of his m ark up EEA range, relecting the greater integration costs for engine technologies. divide tec into three 2 . 1 4D uleep ( 2 0 0 8 ) proposed using judgm ent to hnologies 1 . 7 for treq uiring 1 . 5 6groups. H e recom m ended a m ark up factor ofechnologies ex tensive integration engineering, 1 . 5 6 for those avinghaverage integration costs, and 1 . 4 for those with little or no integrat ion costs.

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ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

bolt them together to produce a vehicle that m eets custom The EP A study ( R ogoz hin et al. , 2 0 0 9 ) estim s ated R 7 ers’ ex pectations and satisies all regulatory req rem ui ents. for the largest m anufacturers for the year 2 0 0 7 using publicly Integrating a new engine or transm ission to decreas e fuel available data in m anufacturers’ annual reports. veral S e asconsum ption will have m uch greater ram iications vehicle for sum ptions were req uired to infer com ponents notorted, rep design and is lik ely to generate greater integration costs than or reported in different ways by different m anufact urers. sim pler com ponents. The m ethod is sim ilar to that used by Bussm an () 2and 0 0 8 In a presentation to the com m ittee, the EP A conraised produced sim ilar results. One notable difference that is the cerns that m ark up factors on piece or supplier cost s tended estim ates shown in Table 3 . 6 attem pt to ex clude acy health leg to overestim ate the costs of m ost fuel econom ynologies: tech care costs, estim ated at 4 5 percent of total health care costs, “Our irst preference is to m ak e an ex plicit estimof ate all which in turn were estim ated to be 3 percent of ly fulburindirect costs rather than rely on general m ark up actors” f dened m anufacturing costs. This would lower the est im ated ( EP A , 2 0 0 8 b, slide 4 ) . Nonetheless, inntitsofassessm the eR P Es by 1 to 2 percent relative to estim ateserinreports, oth costs of greenhouse gas m itigation technologies forlightall else being eq ual. The estim ated R P E m ultipliers were duty vehicles, the EP A staff assum ed a uniformupm of 5ark 0 rem ark ably consistent across m anufacturers ( Table . 6 ) 3 and percent over supplier costs ( i. e. , a m ark up factor of 1 . 5 ) . Svery till,com parable to the studies cited above. Estimed at R P E the EP A m aintains that such a m ark up is too “W large: e be- m ultipliers ranged from 1 . 4 2 for H yundairtoNissan, 1 . 4 9 fo lieve that this indirect cost m ark up overstates the increm ental with an industry average of 1 . 4 6 . A dding 1 cent to 2 for per indirect costs because it is based on studies that include cost health care costs would bring the average m ultiplie r even elem ents—such as funding of pensions—which we belie ve closer to 1 . 5 . are unlik ely to change as a result of the introduction of new technology” ( EP A , 2 0 0 8 a, p. 4 7 ) . Estimating Technology-Speciic Markup Factors and IC F ollowing up on this assertion, the EP A com md issione Multipliers a study of R P E factors and indirect cost ( IC) m pliers ulti ( R ogoz hin et al. , 2 0 0 9 ) . The IC m ultiplier to im attem - pts The assertion that different technologies will induce difprove on the R P E by including only those speciicem el ents ferent changes in indirect costs seem s evident. The q uestion of indirect costs that are lik ely to be affected byvehicle is how to identify and m easure the differences. A the tpresent m odiications associated with environm ental regulati on. tim e a rigorous and robust m ethod for estim ating ese th difIn particular, ix ed depreciation costs, health care costs for ferential im pacts does not ex ist ( Bussm ann and ihan, W hin retired work ers, and pensions m ay not be affected ym b any 2 0 0 9 ) . Therefore, it is not clear that the accuracy of fuel vehicle m odiications caused by environm ental regula tions. consum ption cost assessm ent would be increased he by use t The EP A study ( R ogoz hin et al. , 2 0 0 9 ) esalso criticiz of technology- speciic, as opposed to an industry- erage, av the R P E m ethod on the grounds that an increaseheintotal t m ark up factor. The EP A ( R ogoz hin et al. , ever, 2 0 0 9 ) , how cost of producing a vehicle will not be fully relected in the has tak en the irst steps in attem pting to analyzhise problem t increased price of the vehicle due to elasticities of supply and in a way that could lead to a practical m ethod ofstim e ating dem and. F or this reason, the report argues that ufacturer m an technology- speciic m ark up factors. proits should not be included in the R P E m ultiplier. The The EP A - sponsored study ( R ogoz hin et al. , 2 t0 0 9 ) wen com m ittee disagrees with this assertion for twosons. rea F irst, on to estim ate IC m ultipliers as a function of com the plex ity as noted earlier, the global autom otive industry prox ap im ates or scope of the innovation in an autom ak er’s produc ts caused what econom ists term a m onopolistically com m petitive ark et, by the adoption of the technology. A four- class ology typ of that is, a m ark et in which there is product differe ntiation but a innovation was used: high degree of com petition am ong m any irm s. nopoIn a m o listically com petitive m ark et, in the long run full thecosts of • Incremental inno vatio describes n technologies that production will be passed on to consum ers. In theong l run, req uire only m inor changes to an ex isting product m onopolistically com petitive m ark et supply is ctly perfe elasand perm it the continued use of an established desi gn. tic at the long- run average cost of production ( thi s includes L ow- rolling- resistance tires were given as an ex le am p a norm al rate of return on capital) . S ince costimestates by of increm ental innovation. convention assum e long- run conditions ( full scale conom e ies • Mo du l ar inno vatio is that n which does not change the and learning) , long- run supply assum ptions should e used b to architecture of how com ponents of a vehicle interac t ensure consistency. The increase in R P E is a reason able estibut does change the core concept of the com ponente-r m ate of the change in welfare associated with thencreased i placed. No ex am ple was given for m odular innovation . vehicle cost especially, as noted above, in the lon g run. • Architectu ral inno vatio wasn deined as innovation that req uires changes in the way that vehicle com ponents are link ed together but does not change the core design 7 F or som e parts, the effort req uired for integration m ay be sm all. Tires are concepts. The dual- clutch transm ission was offered often cited as an ex am ple. S till, even tires have im ns plicatio for a vehicle’s as an ex am ple, in that it replaces the function an of suspension and brak ing system s.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

3 5

COST ESTIMATION

TA BL E 3 . 6

Individual M anufacturer and Industry age A R ver etail P rice Eq uivalent ( R P E) M ultipliers: 2 0 0 7 R elative to Cost of S ales

R P E M ultiplier Contributor V ehicle M anufacturing Cost of sales P roduction Overhead W arranty R & D product developm ent D epreciation and am ortiz ation M aintenance, repair, operations cost Total production overhead Corporate Overhead General and adm inistrative R etirem ent H ealth Total corporate overhead S elling Transportation M ark eting D ealers D ealer new vehicle net proit D ealer new vehicle selling cost Total selling and dealer contributors S um of Indirect Costs Net incom e Other costs ( not included as contributors) R P E m ultiplier

Industry A verage

D aim ler Chrysler F ord

GM

1 .0 0

1 .0 0

1 .0 0

0 .0 3 0 .0 5 0 .0 7 0 .0 3 0 .1 8

0 .0 4 0 .0 4 0 .1 1 0 .0 3 0 .2 2

0 .0 3 0 .0 3 0 .0 1 0 .0 2 0 .0 3 0 .0 0 .0 2 0 .0 6 0 .0 7 0 . 005. 0 4 0 . 0 60 . 0 6 0 .0 5 0 .0 6 0 6 0 . 0 05 . 0 9 0 . 0 . 0 8 0 .0 9 0 .30 3 0 . 0 .30 0 .0 3 0 .0 3 0 .0 3 0 .0 3 0 .1 3 0 .1 7 0 . 1 6 2 1 0 . 10 5. 1 9 0 .0 . 2 0

0 .0 7 < 0 .0 1 0 .0 1 0 .0 8

0 .0 5 0 .0 1 < 0 .0 1 0 .0 6

0 .1 2 0 .0 0 < 0 .0 1 0 .1 3

0 .0 7 0 .0 1 0 .0 1 0 .0 8

0 . 1 1. 0 3 < 0 .0 1 0 .0 1 0 .1 4 4

0 .0 4 0 .0 4

0 .0 4 0 .0 2

0 .0 4 0 .0 4

0 .0 4 0 .0 5

0 .0 4 0 .0 4 0 . 003. 0 8 0 . 00 .50 3

< 0 .0 1 0 .0 6 0 .1 4 0 .4 0 0 .0 6 0 .0 4 1 .4 6

< 0 .0 1 < 0 . 0 1 0 1 < 0 . 0 2 , 0 0 0 bar) piez o injectors Total $ 5 2 0

$ 5 4 5

—

$ 9 5

$ 1 2 0

Com m ent H igher load capacity rod bearings andskhead et for ga higher cylinder pressures ( ~ $ 1 2 . 5 0 / cylinder) A low dditional controlairvalves, piping, cost of additional turbo, water- to- air intercooler with separate pum p, contro l valve S witchable pressure f valverelie for high or low oil pressure V ariable output L P pum p controlled essure by high( H Ppr) pum p output Two pressure- sensing glow plugs, one to sense fuel property differences, second to provide on- board diagnosticsdurability back up for irst, already included for both I4 and6Vin Tables 5 . 3 and 5 . 4 A dditional piping ( ~ $ 2 0 ) and valves grated ( e. g. back , inte pressure and L P EGR rate ~ $ 7 5 ) , m uch m ore dificult e for V to pack 6 ag engine with underloor diesel particulate ilter, cost for I4 already included in Table 5 . 4 $ 2 0 / injector, beneits derived from on of com higherbinati rail pressure and m ore injector controllability

$ 8 5 3

TA BL E 5 . 9 Estim ated Total Costs to R eplace 2el-0 Y0 ear 7 M S I od P ower Trains with Base- and A dvancedel CI LP ev ower Trains for Ex am ple M idsiz e S edan and M idsizpee V S U ehicles V - Ty Base- L evel CI Engine M idsiz e S edan I4 engine D CT6 a /transm 7 ission Total M idsiz e S U V V 6 engine D CT6 / 7 transm ission Total

A dvanced- L evel CI Engine

$ 2 , 3 9 3 ( Table 5 . 4 ) or $ 2 , 9 1 3 ( Tables 5 . 4 and 5 . 8 ) or $ 2 , 4 0 0 ( when rounded to nearest $ 5 0 ) $ 2 , 9 0 0 ( when rounded to nearest $ 5 0 ) $ 1 4 0 - $ 4 0 0 ( Table 7 . 1 0 ) $ 1 4 0 - $ 4 0 0 ( Table 7 . 1 0 ) $ 2 , 5 5 0 - $ 2 , 8 0 0 ( when rounded to nearest $ 5 00 )5 0 - $ 3 , 3 $0 30 , ( when rounded to nearest $ 5 0 )

$ 3 , 1 7 4 ( Table 5 . 5 ) or $ 4 , 0 2 7 ( Tables 5 . 5 and 5 . 8 ) or $ 3 , 1 5 0 ( when rounded to nearest $ 5 0 ) $ 4 , 0 5 0 ( when rounded to nearest $ 5 0 ) $ 1 4 0 - $ 4 0 0 ( Table 7 . 1 0 ) ( Table 7 . 1$ 01 )4 0 - $ 4 0 0 $ 3 , 3 0 0 - $ 3 , 5 5 0 ( when rounded to nearest $ 5 01 )5 0 - $ 4 , 4 $5 40 , ( when rounded to nearest $ 5 0 )

aNote that the higher of the two estim ates shown in Table 7 . 1 0 is for a 6 / 7 - speed dual- clutch transm ion ( D iss CT) . In accordance with the potential fuel consum ption reduction gains discussed in Table 5 due . 2 to transm ission im provem ents, it was assum at 7ed- th speed versions would be used. D ue to the wide range of cost estim ates for D CTs as discussed inapter Ch 7 , no adjustm ent was m ade for the higheruetorq req uirem ents of the V 6 CI.

nology com binations for reducing the fuel consum on ptiof ( D CTs) ( 6 - speed) and m ore eficient accessories agespack 2 0 0 7 m odel- year S I gasoline engine vehiclespping by eq ui can reduce fuel consum ption by an average of about3 3 them with advanced CI diesel power trains. percent ( or reduce CO2 em issions by about 2 3 percent) on an eq uivalent vehicle perform ance basis. A dvancedevel l Finding 5 .1 By : a joint effort between OEM s and suppliers, CI diesel engines with advanced D CTs could reduceuel f new em issions control technology has been developedto consum ption by about an additional 1 3 percent arger for l veenable a wide range of light- duty CI engine vehicles to m eet hicles and by about 7 percent for sm all vehiclesth wiengine the 2 0 1 0 Tier 2 , Bin 5 , L EV II em issions standards.displacem ents less than 1 . 5 L . Finding 5 .2:R eplacing 2 0 0 7 m odel year M P F I SFinding I gaso-5 .3The : characteristics of CI diesel engines that enline power trains with base- level CI diesel engines with able their low fuel consum ption apply over the enti re vehicle advanced dual- clutch ( autom ated m anual) transm ns issiooperating range from city driving to highway drivin g, hill

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ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

D ow. 2 0 0 9 . A vailable at http:/ / www. dow. com dL /iterature/ P ublishe dh_ 0 2 df/ 0 9 0 1 b8 0 3 8 0 2 df0 d2 . pdf? filepath= dfs/ autom otive noreg/ 2 9 9 - 5 1 5 0 8 . pdf& from P age= GetD oc. D uleep, K . G. 2 0 0 8 / 2 0 0 9 . D iesel andysis: hybrid EEA cost versus anal M artec, presentation m ade to NR C Com m ittee, y 2F 5ebruar , 2 0 0 8 , updated J une 3 , 2 0 0 9 . EIA ( Energy Inform ation A dm inistration) . 2 ht0 0D9 uty a. L D ig iesel V ehicles: Eficiency and Em issions A ttributes and rk Met Issues. a F ebFinding 5 .4 The : identified advanced- level technology ruary. A vailable at http:/ / www. eia. doe. gov/ oiaf/ icerpt/ serv lightduty/ im provem ents to CI diesel engines are ex pectedeach to r ex ecsum m ary. htm l. m ark et in the 2 0 1 1 - 2 0 1 4 tim e fram e,echwhen advanced EIA . 2t 0 0 9 b. D iesel F uel P rices. A vailable / tonto.ateia. http:/ doe. gov/ oog/ nology additions to S I gasoline engines will also nter e the info/ gdu/ gasdiesel. asp. A ccessed M ay 9 , 2 J0 une 0 95 , , and 2 0 0 9 . EP A ( U . S . Environm ental P rotection A gency) ocum . 2ent 0 04 52 .0 D -F m ark et. Thus, there will continue to be a fuel cons um ption 0 5 - 0 0 1 . A vailable at http:/ / www. epa. gov/e/otaq 4 2 /0clim f0 5 at0 0 1 . htm . and cost com petition between these two power train system s. EP A . 2 0 0 8 . A S tudy of P otential Effectiveness rbon D of ioxCaide R educing F or the period 2 0 1 4 - 2 0 2 0 , further potential nsum fuel p- co V ehicle Technologies. R eport 4 2 0 r8 0 0 4 0 ne. a. R evised J u tion reductions for CI diesel engines m ay be offse t by fuel EP A . 2 0 0 9 . U pdated cost estim ates from. EP those A in , 2U 0. S 0 8 . Com m itconsum ption increases due to engine and em issions ystem s tee e- m ail com m unications with EP A , M ay 2 78 .and M ay H adler, J . , F . R udolph, R . D orenk amD p,üsterdiek H . S tehr, , J . T. H ilz endeger, changes req uired to m eet stricter em issions standar ds ( e. g. , D . M annigel, S . K ranz usch, B. V eldten,and MA . .KS östers, pecht. 2 0 0 8 . L EV III) . V olk swagen’s new 2 . 0 L TD I engine fulills stringent the m ost em ission standards, 2 9 th V ienna M otor S ym posium . Finding 5 .5 CI : diesel engine m ark et penetration will be Iwabuchi, Y . , K . K awai, T. S hoji, and Y 9. 9Tak. Trial eda. of 1 new 9 concept strongly inluenced both by the increm ental cost of CI diesel diesel com bustion system —P rem ix ed com pressionion com ignitbustion. S A E P aper 1 9 9 9 - 0 1 - 0 1 8 5 . S rrendale, A E International, P a. W a power trains above the cost of S I gasoline power tr ains and J oergl, V olk er, P . K eller, O. W eber, K s,. M and uellerR . KH oniecz aa ny. by the price differential of diesel fuel relative to gasoline. 2 0 0 8 . Inluence of pre- turbo catalyst design on el dies engine perforThe estim ated increm ental cost differential forebaslevel and m ance, em issions, and fuel econom y. S A E P0 aper 1 - 20 0 07 81 -. S A E advanced- level I4 CI diesel engines to replace 2 0m0 odel7 International, W arrendale, P a. year m idsiz e sedan S I gasoline engines ranges from $ 2 , 4 0 0 K anda, T. , T. H ak oz ak i, T. U chim oto,KJ itayam . H atano, a, and N. H . S ono. tional diesel fuel. ( base level) to $ 2 , 9 0 0 ( advanced level) . evel F orI4base- l 2 0 0 5 . P CCI operation with early injection of conven S A E P aper 2 0 0 5 - 0 1 - 0 3 7 8 . S A E International, le, P a. W arrenda engines com bined with D CTs, power train replacemcost ent K eller, P . S . , V . J oergl, O. W eber, and i.R 2. 0Cz0 arnowsk 8 . Enabling com is estim ated at $ 2 , 5 5 0 to $ 2 , 8 0 0 andevel for advancedI4 lponents for future clean diesel engines. S A E P 2aper 0 0 8 -0 1 -1 5 3 0 . S A E power trains is estim ated at $ 3 , 0 5 0 to $ 3 rounded , 3 0 0 ( both International, W arrendale, P a. to the nearest $ 5 0 ) . F or m idsiz e 2 0 0 7 m V odels, theyearMS artec U Group, Inc. 2 0 0 8 . V ariable Costs ofnom F uely Eco Technologies. P repared for A lliance of A utom obile M anufacturers, J une 1 ; am ended estim ated cost for replacem ent of S I gasoline engin es with S eptem ber 2 6 and D ecem ber 1 0 . base- level and advanced- level V 6 CI diesel engines ranges M attes, W olfgang, P eter R aschl, and Nik olai t. S2 chuber 0 0 8 . Tailored from $ 3 , 1 5 0 ( base level) to $ 4 , 0 5 0 (( advanced both level) D eNO eco M inNO x concepts for high- perform ance diesel engines. S nd x rounded to the nearest $ 5 0 ) . F or V 6 CI engines inedcom b Conference, J une 1 9 - 2 0 , Berlin. with D CTs, the estim ated V 6 CI power train replacem ent M üller, W . , et al. 2 0 0 3 . S elective catalytic ion—Europe’s reduct NOx reducE Internationa P a. cost increm ent over 2 0 0 7 m odel- year S I power is trains tion technology. S A E 2 0 0 3 - 0 1 - 2 3 0 4 .l,SWA arrendale, M yoshi, N. , et al. 1 9 9 5 . D evelopm ent of threenew concept way catalyst $ 3 , 3 0 0 to $ 3 , 5 5 0 ( base level) , and the el power advanced- lev for autom otive lean- burn engines. S A E P aperS9 A 5 8E 0International, 9 . train increm ental cost is $ 4 , 2 0 0 to $ 4 , 5unded 0 0 ( both ro W arrendale, P a. to nearest $ 5 0 ) . These costs do not include the ailret price NR C ( National R esearch Council) . 2 0 0 2 . Effectivenes s and Im pact of Coreq uivalent factor. porate A verage F uel Econom y ( CA F E) S tandards. nal A Natio cadem y P ress, W ashington, D . C. P eck ham , J ohn. 2 0 0 3 . H ow J D P ower/ LlightM C duty calculate diesel 1 6 % REFERENCES sales share for North A m erica. D iesel F uel News, tober Oc 1 3 . P ick ett, L . M . , and D . L . S iebers. 2 0 low 0 4lam . None tem sooting, perature Bression, G. , D . S oleri, S . S avy, S . D ehoux ulay, H, D. B-. H A .z H o am ouda, m ix ing- controlled D I diesel com bustion. S A 0E0P 4aper - 0 21 - 1 3 9 9 . L . D oradoux , N. Guerrassi, and N. L awrence.study 2 0 of 0m 8 . ethods A S A E International, W arrendale, P a. to lower H C and CO em issions in diesel H CCI. S per A 2E 0P 0a 8 - 0 1 R yan, T. W . , and T. J . Callahan. 1 9 9 6 . H arge om ogeneous com pres-ch 0 0 3 4 . S A E International, W arrendale, P a. sion ignition of diesel fuel. S A E P aper 9 6 1 1 International, 6 0 . S A E D iesel F orum . 2 0 0 8 . A vailable at http:/ /orum www. .dieself org/ D TF / W arrendale, P a. news- center/ pdfs/ D iesel% 2 0 F uel% 2 0 U pdate% 0 2 20 00 - 8%. pdf. 2 0 Oct% 2 S tyles, D . , J . Giuliano, J . H oard, S . orey, S luder, S . JL. ewis, S t and M . D ieselNet. 2 0 0 8 . F ebruary 2 2 . A vailable ww.atdieselnet. http:/ / wcom / L ance. 2 0 0 8 . Identiication and control of factors hat affect t EGR cooler news/ 2 0 0 8 / 0 2 acea. php. fouling. 1 4 th D iesel Engine- Eficiency and Em R issions esearch ConferD OT/ NH TS A ( D epartm ent of Transportation/ ghway National Trafic H i ence, D earborn, M ich. S afety A dm inistration) . 2 0 0 9 . A verage F uel S tandards Econom y Tilgner, Ingo- C. , T. Boger, C. J ask ula, Z . G. H P. L amörch, io, and S . Gom m . P assenger Cars and L ight Truck s—M odel Y ear 2 ck 0 1et 1No. . D o 2 0 0 8 . A new diesel particulate ilter m aterial assenger for pcars: CordiNH TS A - 2 0 0 9 - 0 0 6 2 , R IN 2 1 2 7 - A Kn, 2D 9. ,C.M arch 2 3 . W ashingto erite diesel particulate ilters for the new A udi AV 4 6 TD I, 1 7 . A achener K olloq uium F ahrz eug- und M otorentechnik , p. 3 2 5 .

clim bing, and towing. This attribute of CI diesel engines is an advantage when com pared with other technology op tions that are advantageous for only part of the vehicle operating range ( e. g. , hybrid power trains reduce fuel consum tionp prim arily in city cycle/ city driving) .

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

COMP R ESSION- IGNITION DIESEL ENGINES

ANNEX Table 5 . A . 1 shows the data used in F igure 5 he . 4 for t percentage reduction of fuel consum ption in 2 0 0 ropean 9 Eu vehicle platform s offered with both S I gasoline eng ines and CI diesel engines in conigurations that provide virtually eq ual perform ance ( i. e. , 0 to 1 0 0 k m / htim acceleration es within 5 percent between S I and CI) .

TA BL E 5 . D A ata . 1 U sed in F igure 5 . 4 V ehicle

%

F C R eduction

A udi A 3 BM W 5 2 0 D odge A venger F ord F iesta F ord Galax y H onda Civic H onda CR - V J aguar X F M ercedes E2 3 0 M ercedes S 3 5 0 Toyota Y aris Toyota R A V 4 V W J etta P eugeot 3 0 8 R enault L aguna A udi A 8 A udi Q 7 A udi A 6 M ercedes V iano A V ER A GE

3 0 .8 8 2 5 .0 0 2 0 .5 1 2 6 .3 2 3 6 .7 3 2 1 .2 1 1 8 .5 2 2 9 .2 5 3 1 .1 8 1 7 .6 5 2 5 .0 0 2 4 .4 2 2 8 .3 8 2 8 .7 9 3 4 .6 2 2 1 .3 0 1 8 .3 8 1 8 .1 8 2 3 .5 3 2 5 .2 5

8 3

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

6 Hybrid Power Trains

INTRODUCTION

stop- start behaviors are sim ulated, but virtually o im n provem ent on the highway cycle. H ybrid vehicles achieve reduced fuel consum ption by In addition to the introduction of an electric m oto r, hybrid incorporating in the drive train, in addition to an internal designs m ay include the functions of idle- stop and regencom bustion ( IC) engine, both an energy storage ce devi and a erative brak ing, and the IC engine is freq uently wnsiz do ed m eans of converting the stored energy into m echanic al m otion. from that in its eq uivalent conventional vehicle.s shown A S om e hybrids are also able to convert m echanical tion m into o in Table 6 . A . 1 in the annex at the end of this ter,chap for a stored energy. In its m ost general sense, the stora ge device hybrid vehicle, these operational and physical changes alone can be a battery, lywheel, com pressible luid, elast om er, or in com bination can result in an increase in fuel econom y or ultra capacitor. The m eans of converting energy between ( m pg) of between 1 1 and 1 0 0 percent or a decrease n fuel i storage and m echanical m otion is through the useone of or consum ption ( gallons per 1 0 0 m iles driven) en of 1betwe 0 m ore m otors/ generators ( e. g. , electric, pneum hydraulic) atic, . and 5 0 percent, depending on the vehicle class, isasdisIn m otor m ode, these devices convert stored energy into m ecussed below in this chapter. H ybrid vehicles arehet fastestchanical m otion to propel the vehicle, and in gener ator m ode, growing segm ent of the light- duty vehicle m arklthough et, a these devices convert vehicle m otion into stored en ergy by they still m ak e up less than 3 percent of the new ar mc ark et providing part of the vehicle brak ing function ( reg eneration) . in the U nited S tates. S im ilarly, a fuel cell vehicle is also a hybridwhich in the internal com bustion engine is replaced by the fuel ce ll, but this HYBRID POWER TRAIN SYSTEMS system will lik ely need supplem ental energy storage to m eet peak power dem ands and to allow the fuel cell to siz be ed for A s stated above, hybrid vehicles are deined as havi ng the average power req uirem ent. an internal com bustion engine and one or m ore elect ric m aIn this chapter, hybrid vehicle designs em ployingn a chines that in som e com bination can provide tractiv e force internal com bustion engine and battery- energy stora ge are to propel the vehicle. A n ex ception to this deiniti on is the considered. Battery electric and fuel cell vehicles ( BEV s sim ple idle- stop design, which provides no electric ally deand F CV s) are also briely discussed as other altern ative rived tractive force. D epending on the architectura l conigupower trains. ration of the m otors, generators, and engine, hybri d designs H ybrid electric vehicles incorporate a battery, an elecfall into three classes—parallel, series, and m ix series/ ed tric m otor, and an internal com bustion engine in e drive th parallel. The third design is com m only k nown aserpow split train. In its m ost effective im plem entation this niguraco architecture. S chem atics of these architectures shown are in tion perm its the IC engine to shut down when the ve hicle F igures 6 . 1 , 6 . 2 , and 6 . 3 . W ithin each are class varia-there is decelerating and is stopped, perm its brak ing rgy ene to tions of im plem entation. Broadly deined, the series hybrid be recovered, and perm its the IC engine to be downs iz ed uses the internal com bustion engine for the sole pu rpose of and operated at m ore eficient operating points. should It be driving a generator to charge the battery and/ or powering em phasiz ed that the beneits of hybrids are highly ependent d an electric drive m otor. The electric m otor provide s all the on the drive cycle used to m easure fuel consum ption . F or tractive force. Energy lows from the IC engine thro ugh the ex am ple, a design featuring only idle- stop operatio n, which generator and battery to the m otor. In the parallel and m ix ed shuts off the internal com bustion engine when theehicle v is series/ parallel designs, the IC engine not only cha rges the stopped, will dem onstrate a large im provem enteon cityth battery but also is m echanically connected to the hweels cycle portion of the F ederal Test P rocedure ( F TP where ), and, along with the electric m otor, provides tracti ve power. 8 4

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

8 5

H Y B R ID P OWER TR AINS

Parallel W h eels Motor/ G enerator

Engine

Transmission D ifferential

Electronics

Battery

W h eels

Electrical link Mech anical link

F IGU R E 6 . 1 S chem atic of parallel hybridn power coniguration. trai

F IGU R E 6 . 2 S chem atic of series hybrid power oniguration. train c

H ybrid vehicles are further differentiated by the elative r siz es of the IC engine, battery, and m otor. S om the m e ofore com m on variants of these broad classes are describe d in the following paragraphs. In all cases an econom ica lly and functionally signiicant com ponent of the system the ispower electronic subsystem necessary to control the elect rical part of the drive train. The hybridiz ation of diesel ( com pression ignition;I) C vehicles is ex pected to have som ewhat lower eficien cy beneits than hybridiz ation of gasoline vehicles, in pa rt because conventional CI vehicles already ex hibit lower fuelconsum ption than com parable gasoline vehicles. F urther,vehicles CI also have very low fuel consum ption at idle, m akthe ing beneits of idle- stop less attractive. ConventionalCI power trains are m ore ex pensive than their gasoline count erparts ( see Tables 5 . 4 , 5 . 5 , and 5 . 6 ) , which, when o the added t cost of hybridiz ation, m ak es a CI hybrid powern trai very ex pensive for the additional fuel consum ption reduc tions provided over and above just m oving to a hybrid or CI power train alone. A s a result, it is unlik ely that origi nal eq uipm ent m anufacturers ( OEM s) will offer a wide array hybrids. of CI The m ost lik ely levels of CI hybridiz ation willidlebe stop and, perhaps, som e m ild hybrids. Idle- stop will provide not m uch fuel consum ption reduction on the city driving portion of the F TP test cycle, upon which the judgm ents in this report are based. H owever, OEM s m ay still offer such ologies techn since they provide in- use fuel consum ption reductio ns. In Europe, a num ber of new diesel hybrid vehicles have been announced for production in 2 0 1 0 or 2 0 1 1 ,y especiall for larger and heavier vehicles ( e. g. , L and R over) . There are num erous hybrid vehicles now in productio n, and the com m ittee believes it is m ore representativ e to q uote actual data rather than analyz e the effectiveness of each design to estim ate fuel consum ption beneits. This s preferi able to having the com m ittee and its consultantstim es ate fuel consum ption beneits through sim ulations. assum It is ed that the production vehicles are designed to m eetustom c er ex pectations, including acceleration, passenger spa ce, and adeq uate trunk space. The average fuel consum ption of production hybrid H EV s was determ ined from fuel econom y data supplied by Oak R idge National L aboratory and included as Table 6 . A . 1 in the annex at the end is of chapter. th Belt-Driven Alternator/Starter

In the belt- driven alternator/ starter ( BA S ) design, som etim es k nown as a m icro or m ild hybrid, the and starter generator of a conventional vehicle are replaced by a single F IGU R E 6 . 3 S chem atic of power- split hybrid ainpower belttr or chain- driven larger m achine, capable ofthbo starting coniguration. the engine and generating electric power. In som eAB S designs, in addition to the new belt- driven starter egnerator, the original geared- to- lywheel starter is retained forcold starts. F uel consum ption is reduced by turning off and deco upling the engine at idle and during deceleration. In som designs, e particularly those that have replaced the belt with a chain for

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

8 6

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

increased torq ue transm ission, both electric vehicl e launch and som e degree of brak ing energy regeneration are possible. This m ode of operation is k nown as idle- stop, and hilew not technically q ualifying as a hybrid since the m tor/ o generator provides no or little tractive power, it is included in this chapter for com pleteness. Idle- stop designs reduce fuel consum ption by up to 6 percent in urban drivin g with S I engines ( R icardo, Inc. , 2 0 0 8 ) . F or S I engines g variable havin valve tim ing to reduce inlet throttling loss the be neit m ay be less than 6 percent. F or CI engines, the beneit of idlestop drops to about 1 percent because CI engines are m ore eficient at idle due to their lack of inlet throttling. The BA S design is not q uite as sim ple as it irst pears. ap M aintaining hydraulic pressure in the autom aticnsm tra ission is necessary for sm ooth and rapid restart, and safe ty issues related to unex pected restart m ust be considered.heTcom pany Z F has designed a transm ission that provides m aeans of m aintaining hydraulic pressure using a “hydraulic im pulse storage device” that appears to address the transm ssion i problem ( Transm ission Technology International, 8 2) 0, 0 which is also addressed in ex isting designs by an leectrically driven hydraulic pum p.

architectural approaches to achieving a full hybrid, the three in current production being the integrated starter/generator ( IS G) or integrated m otor assist ( IM A ) , the power split, and the two- m ode. These are all parallel or power split designs. The H EV m ay also provide a lim ited electric-nge onlyif ra the battery capacity and m otor siz e are suficient. The ratio of electric to m echanical power providedfor propulsion of an H EV varies with driving conditions and the state of charge of the battery. This operational feature is accom plished with sophisticated com puter controls. Com m ercially available H EV s such as the Toyota PHrius, onda Civic, Nissan A ltim a, or F ord Escape can support lim aited all- electric range at lim ited speeds. In these vehi cles the battery is operated in a charge- sustaining ( CS ) m e; od that is, the state of charge ( S OC) of the battery isowed all to vary over a very narrow range, typically 1 5 to 2 ercent, 0 p to ensure long battery life. The IC engine operates over a narrow speed/ load range to im prove eficiency, and egenr eration is em ployed to recover brak ing energy. Arding cco to Toyota, as shown in F igure 6 . 4 , the contribution s of stopstart, regenerative brak ing, and engine m odiication s to fuel consum ption im provem ents are approx im ately nd53 , 01 0 , a percent, respectively.

Full Hybrid The full hybrid ( H EV ) has suficient electricalgy ener storage and a powerful enough electric m otor to pro vide signiicant electrical assist to the IC engine during acceleration and regeneration during brak ing. There areseveral

ISG/IMA Hybrid In the IS G/ IM A design, the starter and generator e ar replaced by a larger electrical m achine connectingthe engine and transm ission. These vehicles generally use a larger

F IGU R E 6 . 4 Individual technology contributions uel consum to f ption in hybrid electric vehicles. S OU : RF ushik CE i and W im m er ( 2 0 0 7 ) . R eprinted with perm ission.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

H Y B R ID P OWER TR AINS

8 7

battery and a higher voltage ( e. g. , 1 40 V ) than BAtheS . Series Hybrid A dditionally, the m otor/ generator and battery are owerp The series H EV is conigured with the engine driving ful enough to provide electrical launch from a stopand the a generator providing electric power to charge the batability to support som e degree of electric- only vel. tra In its tery. The wheels are driven by an electric m otor wered po sim plest form the IS G is m echanically ix edCto engine the I from the battery. The only function of the IC engin e is to crank shaft, but in som e designs a second clutchlates iso the charge the battery while driving. Because there is no m eengine and the electrical m achine to enable largerregenchanical connection between the IC engine and the wheels, eration of brak ing energy ( D an H ancock , General ors,M ot the m otor and the battery m ust be siz ed for theicle’s veh personal com m unication, Novem ber 3 0 , 2 0 0 7 ) . W hen incorfull torq ue and power req uirem ents. The advantages of this porating an effective regenerative brak ing system the , IS G coniguration are that a sm aller engine can be usedsince it hybrid achieves a fuel consum ption reduction of 3percent 4 is not req uired to provide the power needed for accelerain the com bined driving cycle, as dem onstratedhe byHt onda tion, and the engine can be optim iz ed with respect to fuel Civic. A part of the im proved fuel consum ptionscom from e consum ption. A t present the only OEM planningiesa ser vehicle m odiications, including the use of a sm r,alle m ore hybrid is GM , which is proposing it as a plug- inbrid hy eficient S I engine. electric vehicle ( P H EV ) . Power-Split Hybrid

Plug-In Hybrid The power- split hybrid design, typiied by the Toyot a The principal difference between the previously described P rius, the F ord Escape, and the Nissan A ltim rporates a, inco H EV variants and the P H EV is that the latter ed with is itt a differential gear set that connects together the IC engine, a larger battery that can be charged from the elect ric utility an electrical generator, and the drive shaft. The drive shaft grid ( “plugged in”) and that operates in a charge-epleting d is also connected to an electric m otor. This m echan ical conm ode; that is, the state of charge of the battery s allowed i iguration incorporating the addition of a generator provides to vary over a m uch larger range, 5 0 percent being typically the lex ibility of several operational m odes. Inticular par the proposed. The signiicant fuel consum ption beneit is obwheels can be driven by both the IC engine and the electric tained during urban driving when the vehicle can be driven m otor, with the m otor’s power com ing from the ator, gener on electric power only. Once the all- electric rangehas been not the battery. The car is thus driven in both series and achieved and the battery discharged to its lowest allowparallel m odes sim ultaneously, which is not a ible possm ode able state of charge, the vehicle is operated in the chargefor the IS G design. This operational m ode allowse th IC sustaining m ode and differs little from the H EV sm . all A engine operation to be optim iz ed for m ax im um ion in reduct industry has developed around the conversion of the P rius fuel consum ption. The vehicles that use this power split depower- split H EV s to P H EV s by supplem enting ery the batt sign show a range of fuel consum ption reduction fro m 1 0 to and m odifying the control electronics. 5 0 percent. The low end of this range is the Toyota L ex us, the P H EV s req uire a m uch larger battery than other ids hybr design of which is optim iz ed for perform ance, ow notfuel l ( 4 to 2 4 k 1 W depending h) on the desired electric- only consum ption. In Chapter 9 , where the com m ittee m ates esti range. There has been m uch activity related to P Hs since EV fuel consum ption beneits for vehicle classes, theex L us is the com m ittee inaugurated its work in 2 0 0 7 .eral The Gen not used in the range of beneits for the power split design. M otors V olt m entioned above is planned for introdu ction in This gives the fuel consum ption beneits from thewer po split 2 0 1 0 provided that a suitable battery is developed ( Tate et design a range of 2 4 to 5 0 percent. al. , 2 0 0 9 ) . The V olt currently is ex pected unched to belate la General M otors ( GM ) is work ing with BM W erand Chrysl in 2 0 1 0 as a 2 0 1 1 m odel. Toyota has alsoplans announced on a different split hybrid architecture that uses the so- called for a plug- in hybrid for 2 0 1 1 , although it will builtbeon a two- m ode system ( Grewe et al. , 2 0 0 7 ) . its This thealso spl P rius platform using its power split architecture F (ushik i power low from the engine but uses m ore clutchesd an gears and W im m er, 2 0 0 7 ) . In addition to the V P rius, olt and the to m atch the load to the drive and m inim iz ecal electri losses. the V olk swagen Golf P H EV is ex pected in 2 0rd’s 1 0 and F o The claim is that by using m ultiple gears the drive is m ore Escape S U V P H EV is due out to the general2public 0 1 in 2 . eficient in real- world driving situations and reduces fuel A P H EV in China went on sale to the public in early China consum ption when towing a trailer or driving at hig h speed. in 2 0 1 0 . Toyota is using a sim ilar approach with one or two gears in W hile the m icro and IS G hybrids offer som e im proveits latest hybrid system s. The fuel consum ptionuction red m ent in fuel consum ption for a relatively m odest st, co it is for the two- m ode power split design, characterizby edthe Chevrolet Tahoe and S aturn V ue, ranges from 2 59 to per1 The Energy Independence and S ecurity A ct of 2 0 eines 0 7 ad plug- in cent. H owever, the com m ittee think s that other em imentapl that draws m otive power tions of the two- m ode system could provide a m m ax im fuel u hybrid as a light- , m edium - , or heavy- duty vehicle from a battery with a capacity of at least 4 k ilowa tt- hours and can be reconsum ption beneit of about 4 5 percent. charged from an ex ternal source of electricity.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

8 8

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

the power- split H EV and P H EV architecturesmthat isepro a signiicant im provem ent. The P H EV also offers the longterm potential for displacing fossil fuels with oth er prim ary energy sources such as nuclear or renewable sources of electricity, depending on the fuel source of the electric grid from which the P H EV draws electricity. Battery Electric Vehicles

the Tesla S , with a range of 1 6 0 , 2 3 0 , or, 3depending 0 0 m iles on optional battery siz e.4 Nissan has also announced production of its L eaf EV , a ive- passenger car with ageran of 1 0 0 5 This vehicle has a L i- ion battery with a total sto m iles. rage capacity of 2 4 k W h. W ithin the horiz on of this study, the m ost lik uture ely f for large num bers of battery electric vehicles inhet U nited S tates is in the lim ited- range, sm all- vehiclet.mR ark angee ex tended electric vehicles ( hybrids and P H EV m s) are ore lik ely to satisfy the electricity- fueled full- perfo rm ance— m ark et, from both cost and technological considerat ions, over the nex t 1 5 years.

The prospect for widespread introduction of fullperform ance all- electric vehicles depends on signii cant advancem ents of the battery technologies discussedabove, and the com m ercial viability of these vehicles depe nds on a battery cost break through. A dvances in electricotors, m BATTERY TECHNOLOGY power electronics, and batteries for autom otive app lications, which have resulted from the developm ent and produc tion In spite of the signiicant progress that battery technology of hybrid vehicles, have renewed interest in the developm ent has ex perienced in the last 2 0 years, the battery s still i the of battery electric vehicles. H owever, the cost,wloenergy m ost challenging technology in the design of hybrid vehicles. density, and req uired charging tim e of batteriesllwi continue F igure 6 . 5 illustrates the dram atic differenceeen betw the ento constrain the introduction of BEV s. The high low - speed ergy densities of today’s com m ercial batteries and gasoline, torq ue perform ance of electric m otors gives the BEV a diesel fuel, ethanol, com pressed natural gas, and ydrogen. h potential acceleration advantage over conventional internal A t the tim e of this report, all production hybrid ehicles v used com bustion engine- powered vehicles, and this can an be atbatteries em ploying nick el- m etal- hydride ( NiMm His-) che tractive feature for som e custom ers try. It is anticipated that the NiM H battery will e replaced b A review of z ero- em ission vehicle technology com by - L i- ion batteries in the near future. The accepta bility of m issioned by the California A ir R esources BoardR( CA B) today’s hybrid vehicles has been shown to be strongly deconcluded that com m ercializ ation ( tens of thousands of pendent on the price of gasoline, as evidenced by the rapid vehicles) of full- perform ance battery electric vehi cles would growth of hybrid sales in 2 0 0 8 , when gasoline sprice were not occur before 2 0 1 5 and that m ass production dreds ( hun high, and the fact that hybrid sales dropped dram ically at in of thousands of vehicles) would not occur before 2 30 0 early 2 0 0 9 when prices returned to lower values. e kTh ey to ( K alham m er et al. , 2 0 0 7 ) . These projections sed onwere ba im proving the com petitive position of hybrid vehicl es of the the continued developm ent of lithium - ion ( L i-attery ion) b H EV and P H EV types is the com m ercial developm ent o technology leading to reduced cost, higher energy densibatteries with param eters that are substantially be tter than ties, and reduced charging tim es, all of which allo w greater those of today’s batteries, leading to reduced cost and siz e. range. They pointed to a possible role for a lim diterange, The req uired param etric im provem ents are as follows : city electric vehicle ( CEV ) , which could m eeteqtheuirer m ents of a m ajority of household trips. H owever, recent BEV • H igher cycle life at increased S OC variation, introductions suggest that progress in the technology and • H igher energy density, acceptance of L i- ion batteries m ay be m ore rapid an the th • H igher power density, and CA R B study concluded. • L ower cost. Early com m ercial application of L i- ion battery nology tech to vehicles includes the Tesla R oadster, a high- rform pe ance F igure 6 . 6 shows the desirable characteristicsatteries of b sports car. This vehicle, of which about 1 , 0 0 0 been have suitable for the H EV , the P H EV , and the call( EV electri or sold, has a fuel consum ption of 0 . 7 4 gal/ 1 0( energy 0 m iles BEV ) vehicles. The H EV uses electric propulsion m arily pri 2 The m. anueq uivalent basis, EP A com bined city/ highway) as an assist to the IC engine, thus req uiring a bat tery with facturer claim s a range of 2 4 4 m iles ( also EPined A coma high b power capability but relatively little energy capacity, city/ highway) and a useful battery life of m ore ntha 1 0 0 , 0 0 0i. e. , a high power to energy ( P / E) ratio. To ve preser battery 3 The base price of $ 1 2 8 , 0 0 0 indicates the continuin m iles. g life and m aintain the capacity to recover charge th rough problem of battery cost when used in near full- perf orm ance regenerative brak ing, the battery is cycled over arelatively vehicles. Tesla has announced that it will produce and sell, sm all state of charge. This m ode of operation isown k nas at about half the price of the R oadster, a ive- pass enger BEV , charge sustaining ( CS ) . The P H EV is ex pected videto pro 2 California

A ir R esources Board ( 2 0 0 9 ) , available t http:/ / awww. 4 S ee http:/ / news. cnet. com / tesla- m otors- ceodriveclean. ca. gov. is-mcheaperodel- s-than3 Tesla M otors ( 2 0 0 9 ) , available at http:/ / m www. otors. tesla com / display_ it- look s/ . data/ teslaroadster_ specsheet. pdf; IEEE V ehicular chnology, Te M arch 2 0 1 0 . 5 S ee http:/ / www. nissanusa. com / leaf- electric-r.car/ jsp#tou / details.

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F IGU R E 6 . 5 V olum etric and gravim etric ies energy of different densit energy storage m echanism s. S OU F Rushik CE: i and W im m er ( 2 0 0 7 ) . R eprinted with perm ission.

F IGU R E 6 . 6 Energy capacity, state- of- charge on, variati and relative power density to energy density ratios for batteries applicable to fullhybrid ( H EV ) , plug- in hybrid ( P H EV ) , icand ( EV all- electr ) vehicles. The units of P / E are k W / k W h. S OU R CE: A m ine ( 2 0 0 7 ) .

som e degree of electric- only range. Its battery mt therefore us contain suficient energy to provide this range. The battery m ay be allowed to ex pend all of its stored energy o achieve t this range goal, in which case the battery is saidto be operated in the charge- depleting ( CD ) m ode. The power eq uirer m ent of this battery is not m uch different fromt oftha the

H EV battery, but because of the higher energy req remui ent, the P / E ratio is sm aller. The BEV req uires an higher evenenergy capacity battery than the P H EV , the valuending depe on the desired driving range. S ince the BEV has noengine, IC its battery cannot be charged during driving, and therefore it cannot operate in a CS m ode. In all cases the S ariation OC v

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ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

is lim ited to a speciied range by the vehicle m anuf acturer to preserve battery cycle life. F igure 6 . 6 shows al typic ranges for the H EV , P H EV , and ThusBEV the usable . energy is less than the battery rated ( or “nam eplate”) capacity. D espite substantial im provem ents in the pack and aging perform ance of lead- acid batteries, their energydan power densities are still considerably inferior to those of NiM H . A nd while other chem istries, lik e L i- air, have retically theo better perform ance than L i- ion, their developms not entati a stage where one could envision them in practical au tom otive applications within the tim eline of this study. The refore the com m ittee considers only NiM H and L i- ion as rieschem of interest here.

shown in Table 6 . 1 . The colum n heads denote the- com m on abbreviation for the different chem istries: NCA ( nick el- cobalt- alum inum ) , L F P ( lithiumate)- iron, phosph M S ( m anganese- spinel) , M NS ( m anganese) , nick el- spin and M N ( m anganese- nick el) . The irst entry gives the detailed com position of the anode and cathode m ials, ater with the positive ( cathode) m aterial shown irst.e Th second entry gives the gravim etric energy density of thehem c istry in m illiam pere- hours/ gram ( m A h/ g) , the shows third entry the open- circuit term inal voltage when the cell 5is 0 percent depleted ( 5 0 percent state of charge) , and fourth the entry ist gives the area speciic im pedance ( A S I) as sured m ea during a 1 0 - second pulse at the 5 C rate, whichndicais i tive of the battery’s ability to provide power necessary for acceleration. The relative safety of the differentchem istries NiMH Batteries is given in the ifth entry. The safety of using L ion i- batThe highest- perform ance battery currently available in teries has received considerable attention since the 2 0 0 6 com m ercially signiicant q uantities for H EV s and V sP H recall E of L i- ion batteries used in laptops. In som e of the uses NiM H chem istry. D espite signiicant im provem s in ent chem istries, particularly those using a cobalt ( Co) - based lifetim e and pack aging, these batteries are still x pensive, e cathode, failure can occur due to overheating or separator heavy, and in application are restricted to a S OCange r of failure. This problem is well k nown, and safetya is charabout 2 0 percent to preserve battery cycle life. cause Be acteriz ing param eter com m on to all the L i system S om s. e of their relatively poor charge/ discharge eficiency, special m anufacturers believe they can solve the safety pro blem consideration m ust be given to their therm al m anage through careful m onitoring and charge control. R tive ela m ent. The NiM H chem istry also ex hibits a high of ratecost am ong the different L i chem istries is shown thein self- discharge. seventh entry, although at this tim e the absoluteost c of all The m ost technically advanced NiM H battery used the in is considerably higher than the cost for NiM H . The last Toyota P rius has a weight of 4 5 k g and an energy pacity ca of entry in Table 6 . 1 indicates the state of the techn ology. P ilot 1 . 3 1 k W h. This results in a usable energy ofimapprox ately scale indicates that cells are currently being m anu factured 0 . 2 6 2 k W h when applied with a S OC variation ercent. of 2 0 pin suficient q uantities for testing in vehicle leets of lim ited siz e. D evelopm ent m eans that the chem istryconis well trolled, but the production of practical cells is anticipated Li-Ion Batteries and under developm ent. R esearch indicates just —the that The m ost prom ising battery technologies are those chem istry is still a subject of research, and theroduction p em ploying various L i- ion chem istries. Characteristi cs of of cells using the chem istry has not been dem onstra ted to the m ore com m on lithium - based cell com positionsanare ex tent suficient to anticipate their use.

TA BL E 6 . 1

Com parative Characteristics and Mof Laturity ithium - Ion Battery Chem istries Battery S ystem NCA - Graphite

Electrodes P ositive Negative Capacity, m A h/ g P ositive Negative V oltage, 5 0 % state of charge A S I for 1 0 - s, S afety L ife potential Cost S tatus

L F P - Graphite

M S - TiO

M NS - TiO

M N- Graphite

L iNi 0 .Co 8 0 . 1A5 0l . 0O52 Graphite

L iF eP4 O Graphite

L iM2On4 L 4iTi5O1 2

L iM1 .Ni n5 0 .O 54 L 4iTi5O1 2

L 1i .M 2 0 n.Ni 6 0 .O 22 Graphite

1 5 5 2 9 0 3 .6

1 6 2 2 9 0 3 .3 5

1 0 0 1 7 0

1 3 0 1 7 0

2 7 5 2 9 0

2 5 F air Good M oderate P ilot scale

2 5 Good Good M oderate P ilot scale

2 .5 2 9 .2 Ex cellent Ex cellent L ow D evelop.

3 .1 4 1 0 0 Ex cellent U nk nown M oderate R esearch

3 .9 2 5 Ex cellent U nk nown M oderate hR esearc

NOTE: NCA , Ni- Co- A l; L F P ,4; LMi- F P O M n( S pinel) - Ti- O; M NS - TiO,i-MO; nS e- TiO, M Ni( N-SGraphite, pinel) - TM n- Ni- Graphite.

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The relative gravim etric energy densities of L i-, ion NiM H , POWER ELECTRONICS and P b- acid are approx im ately 4 , 2 , and 1vely. , respecti A n The term p o w er el ectrorefers nics to the sem iconductor additional advantage of the L i system s is their hhig cell potenswitches and their associated circuitry that are used to tial, approx im ately 3 tim es that of NiM H .s This that 6m6 ean control the power supplied to the electrical m achin es or percent fewer L i- ion cells are req uired to achieve a given batto charge the battery in an H EV or P H EV . F esorofpurpos tery voltage. The ecologically benign m aterials in the L i- ion driving electric m otors these circuits function as an inverter, system s are also an advantage. A disadvantage of - ion L icells changing the battery direct voltage into an alternating voltis that the req uirem ent for cleanliness in the m facturing anu age of controlled am plitude and freq uency. F or ging char environm ent is considerably m ore severe than forMNi H the propulsion battery they function as a controlled recticells ( Z em pachi Ogum i, K yoto U niversity, om personal m u-c ier, changing the ac voltage of the m achine to the dc value nication, D ecem ber 8 , 2 0 0 8 ) . This increases turing m anufac req uired by the battery. The direction of power low is either costs. A nother critical issue is how the perform eanc of L i- ion into or out of the battery, depending on vehicle m deo of batteries is im pacted by low and high tem peratures ( A m ine, operation. P lug- in hybrids also req uire power elect ronic 2 0 0 7 ; R eilly, 2 0 0 7 ; A nderm ann, 2 0 0 7 ) . circuits to convert the ac m ain voltage to a precis e dc voltage The irst three colum ns in Table 6 . 1 —NCA - Graphite, to charge the propulsion battery. L F P - Graphite, and M S - TiO—represent the m ng ost prom isi P ower electronic circuits k nown as dc/ dc converters L i- ion system s currently under developm ent. The- NCA change the propulsion battery dc voltage to the dc voltage apgraphite chem istry is used by J CS / S A F T in its V L 4 1 M propriate to charging the accessory battery ( i. e.the , standard m odule that has undergone dynam om eter testingToyota in a 1 2 V battery retained to power vehicle accessories) . A dc/ dc P rius at A rgonne National L aboratories ( A NL eau ) ( R ouss converter m ay also be used to increase system efici ency et al. , 2 0 0 7 ) . The lithium - iron phosphate tem ( L F isP ) sys by stepping up the propulsion battery voltage before it is currently receiving a great deal of attention because of its supplied to the inverter. The latest Toyota P rius ses u such stability, potentially lower m aterial costs, ands application it a design. in power tools. Its developm ent is being aggressive ly pursued Both inverter and dc/ dc converter technologies are well by A 1 2 3 and Enerdel. The m anganese- spinel-itanate lithium - t developed for industrial and other applications. The special system ( M S - TiO) is the safest of any being because studied problem s for hybrid vehicles are cost, cooling, and pack of the m echanical stability of the spinel structure , but its cell aging. A lthough the am bient environm ent for autom ive ot voltage is considerably lower than those of the NCA and electronics is m uch harsher than that in industrialor com L F P system s. H owever, it has the highest charge/ charge dis m ercial applications, the cost in the autom otive application is eficiency, and it is predicted to be the lowest- cos t system . req uired to be lower. F igure 6 . 7 illustrates provem the im ent To put in perspective the m erits of the L i- ionery battrelaover a 1 0 - year period in the volum etric power densi ty of the tive to NiM H , consider the req uirem ents for ale2all0 -m i m otor drive inverter for Toyota’s hybrid product ne. li The electric range P H EV . A ccording to an A NL lson study et ( Ne signiicant im provem ent after 2 0 0 5 is due ineasure large m al. , 2 0 0 7 ) , which assum ed a 1 0 0 to 1 0ange, percent the S OC r to the increased switching freq uency m ade possible by the req uired battery capacity for its assum ed vehicle s 6i . 7 k W h. higher- speed m otor and higher voltage introduced 2in 0 0 5 . F or an M S - TiO battery the calculated weight isk1g.0 If 0 These changes reduce the physical siz e of m agnetic com an NiM H battery were used, with a S OC range of o 82 0 t ponents and im prove the utiliz ation of silicon devi ces. Both percent and a gravim etric energy density one- halfhatt of these conseq uences result in im proved pack agingsity. den the M S - TiO system , the com m ittee estim would ates that it req uire a capacity of 1 0 . 3 5 k W h and weigh 3 0 0 k g. The needs of H EV s and P H EV s are q uite distinct,ROTATING as ELECTRICAL MACHINES AND shown in F igure 6 . 6 . H EV s need high power density nd aCONTROLLERS long cycle life over a very sm all ex cursion of the S OC. F or W ith the possible ex ception of m icrohybrids, hicles all ve ex am ple the P rius battery has a nom inal rating . 3ofk1 W h use perm anent m agnet alternating current m otors. nce the S i but it uses only 2 6 0 W h−1in 0+ /percent ex cursions around battery capacity is the k ey lim itation for hybridehicles, v 5 0 percent S OC. On the other hand, the larger energ y reelectrical m achine eficiency is of param ount im ance. port q uirem ent of the P H EV argues for a battery with ighera h M ost system s em ploy “buried m agnet” rotating m achine energy rating and the capability of deeper cycling. The V olt, conigurations with ex pensive rare- earth high- streng th m agthe P H EV being developed by GM , uses a 1 6 - ry k W h batte nets. GM and H onda are using lat wire for the arm ure at to m eet its advertised all- electric range of 4 0 es.m This il winding to increase eficiency. A lthough rectangular conducis a substantial challenge to achieve at acceptable weight, tors are com m on for large m achines, their uselatively in re volum e, and cost. The L i- ion chem istry com testocloses sm all m achines shows the ex tent to which m anufactur ers are m eeting it, given the present state of battery deve lopm ent. It going to get better eficiency. R otating m achinehnologies tec should be noted that the V olt is designed to use on ly 8 k W h and designs are well developed, and the autom otive applicaby operating from 8 0 percent to 3 0 percent S OC.

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F IGU R E 6 . 7 sion of Toyota.

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Evolution of hybrid drive inverteretric volum power density. SOU R CE: F ushik i and W im m er ( 2 0 0 7 ) perm . F igure is- used with

tion challenge is to lower their m anufacturing cost . Because achieved by increasing the speed of the electric m tor o in its rotating m achines are such a m ature com ponent, cost theof hybrid vehicles. their m anufacture in high volum es is driven princip ally by Com puters have been used to control em issions and p- o the cost of m aterials. Thus their cost is relativel y unrespontim iz e eficiency of conventional power trains. In ddition a sive to technology developm ents. M ajor im provem in ents to engine control, controllers in hybrid vehicles monitor the volum etric power density can be achieved by increas ing the state of charge of the battery and determ ine power lows to and speed of the m otor. This volum etric im provem ults entinres from the battery and engine. The control task isre mcom o plex m aterials reduction but generally also in increasedlosses. for the P H EV where there is a greater opportunity o optim t iz e H igh- speed m otors also req uire a gear set to mtheatch m ethe tradeoff between electric and IC engine use with respect chanical speed req uired of the drive train. W hile he design t to fuel consum ption. One suggested approach is toave h the of the m otor/ inverter system is an optim iz ation blempro, controller predeterm ine the propulsion proile from ex pected no technology break throughs that would radically improve route data provided by the driver or an off- board wirelessly the state of the art are foreseen. F igure 6 . 8 trates illus the connected server. V ehicle com puters are powerful ough en to im provem ent in volum etric power density that Toyota has handle these task s, and no technical problem s are x pected. e

F IGU R E 6 . 8 Evolution of the volum etric power y ofdensit electric m otors used in Toyota’s hybrid vehicl es. S OU R CE: F ushik i and W im m er ( 2 0 0 7 ) . F igure used with perm ission of Toyota.

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H Y B R ID P OWER TR AINS

COST ESTIMATES

justiication for using an R P E of 1 . 3 3 for hybrids s that the i factory cost estim ates it developed already include engineerThe objective in determ ining costs of new technolog ies is ing costs and other part costs, including labor andoverhead, understanding their factory cost. The factory cost is the direct for integrating the technology. U sing a cost m ultip lier of 1 . 5 cost to the OEM of replacing ex isting productionchnology te would double count these costs. A by technology B. It is determ ined as follows: A s an ex am ple of the process, Table 6 . 2 shows ti- an es m ated break down of the factory cost of a “m ature” rius—a P 1 . Tak e the price B)( that a supplier charges the OEM for P rius- type drive that has beneited from the learnin g curve technology B; and has an annual production volum e in ex cess of 01 ,00 0 0 2 . A dd the engineering cost C) ( to the OEM of integrating units. The additional com ponents and their estim d ate OEM technology B into a vehicle; costs from the supplier are listed. The com m lso itteelists a 3 . A dd the cost D) ( of any parts that the OEM m ak es the cost decrem ent of item s, such as the automtransm atic isin- house to im plem ent the technology ( labor cost us pl sion, that will be rem oved from the baseline vehicle, a Toyota factory overhead, plus am ortiz ation of req uired new Corolla in this case. The net cost increase for them ature P rius investm ent) ; and is then calculated as $ 3 , 3 8 5 . 4 . S ubtract the costA)( of technology A sim ilarly Nex t the com m ittee projects costs for 5 - year ents increm calculated. to 2 0 2 5 , as shown in Table 6 . 3 . P ercentage uctions cost red The facto ry coisstthen B + C + D – A. The cost estim ates have been validated by soliciting a pplied t feedback from a num ber of U . S . and J apanese dOEM TA s anBL E 6 . 2 F actory Cost Estim ation P rocesso A M ature P rius- type H ybrid V ehicle in U . S . D ollars suppliers. The costs presented here are a consensus that the num bers are “about right. ” The costs of hybrid tech nologies F actory Cost vary depending on the degree of hybridiz ation, froma low 2 0 k W (B + C + D − A) cost in the case of the BA S design, to a very high cost for a M otor/ generator/ gears 1 ,1 0 0 series P H EV . It should be noted that the factory st deinico Control electronics + dc/ dc ( 1 . 2 k W ) 1 ,1 0 0 tion used here includes engineering costs and other part costs, Battery ( NiM H 2 1 k W ) 1 ,0 0 0 Electrical accessories 1 0 0 including labor and overhead, for integrating the technology. Electric P S and water pum p 2 0 0 U sing the studies described in Chapter 3 , the comtteemde-i A utom atic transm ission −8 5 0 veloped a different m ark up factor for hybrids that relates he t R egenerative brak es 2 5 0 deinition of factory cost to R P E. A lthough differen t studies Electric A / C 3 0 0 use different deinitions and allocations for item ssuch as Engine downsiz e −1 2 0 proit, vehicle warranty, corporate overhead, transp ortation, S tarter and alternator −9 5 m ark eting, and dealer costs, the com m ittee conclude d that H igh- voltage cables ( M artec 5 0 0 V ) 2 0 0 Body/ chassis/ special com ponents 2 0 0 the factory m ark up for hybrids should be on the ord er of Total 3 ,3 8 5 1 . 3 3 rather than 1 . 5 for factory cost to R PomE. m Theittee’s c

TA BL E 6 . 3

P rojections of the F uture F actory aM Costature of P rius- type H ybrid in U . S . D ollars F actory Cost (B + C + D − A)

2 0 k W

Cost R eductions ( % )

M otor/ generator/ gears 5 Control electronics + dc/ dc ( 1 . 2 k W ) 1 5 Battery ( NiM H 2 1 k W , L i- ion M artec) 1 5 Electrical accessories 5 Electric P S and water pum p 5 A utom atic transm ission 0 R egenerative brak es 5 Electric A / C 1 0 Engine downsiz e 0 S tarter and alternator 0 H igh- voltage cables ( M artec 5 0 0 V ) 1 0 Body/ chassis/ special com ponents 1 0 Total

2 0 0 8

2 0 1 5

2 0 2 0

2 0 2 5

1 ,1 0 0 1 ,0 5 0 9 9 0 9 4 0 1 ,1 0 0 9 4 0 08 0 0 6 8 1 ,0 0 0 8 5 0 7 2 0 7 1 0 0 9 0 9 0 8 5 2 0 0 1 9 0 1 8 0 1 7 0 −8 5 0 −8 5 0 −8 5 0 −8 5 0 2 5 0 2 4 0 2 3 0 2 1 0 3 0 0 2 7 0 2 4 0 2 2 0 −1 2 0 −1 2 0 −1 2 0 −1 2 0 −9 5 −9 5 −9 5 −9 5 2 0 0 1 8 0 1 6 0 1 5 0 2 0 0 1 8 0 1 6 0 1 5 0 3 ,3 8 5 2 ,9 2 5 2 ,5 0 5 2 ,2 6 0

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9 4

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

appropriate for each com ponent are used. F or ex e, am pl FUEL CONSUMPTION BENEFITS OF HYBRID ex pected reductions are on the order of 1 5 percent for each ARCHITECTURES 5 - year period for the battery and control electroni cs, 5 perA s noted earlier, the average fuel consum ptionroducof p cent for the electrical m achines, and no change in cost for tion hybrid H EV s was determ ined from fuel econom ata y d the m ature com ponents such as engine downsiz ing, d the an supplied by Oak R idge National L aboratory and inclu ded as alternator. Table 6 . A . 1 in the annex at the end of this chapter . F or sevA sim ilar analysis has been done for the other hybri d eral speciic m odels, these data were com pared to ta da from classes, and the sum m ary results are shownTable in 6 . 4 . It conventional ( nonhybrid) vehicles of approx im ately sim ilar should be noted that future costs for P H EV s and EV are s perform ance and physical speciications, and the res ults highly uncertain due to the uncertainties in future battery are shown in Table 6 . 5 . A s m entioned earlier, niicant a sig chem istries and tradeoffs between power and energy. L i- ion contribution to the fuel consum ption beneit of hybr id vebatteries for consum er electronics are a com m ercial techhicles is due to m odiications to the engine, body, and tires. nology, and costs have gone down along the learningcurve. F or ex am ple, the fuel econom y of the P riusicantly is signi H owever, m any OEM s and battery suppliers are ing ex pect inluenced by engine im provem ents and optim iz ed ating oper large cost reductions for L i- ion batteries with inc reasing area. The 2 0 0 7 m odel- year version of the S aturn hybrid, V ue applications in vehicles. A m ong its provisions ted relato which used a BA S design, ex hibits a 2 5 percent im provem ent fuel econom y, the Energy Independence and S ecurity A ct of in fuel econom y on the F TP cycle, but approx imhalfately of 2 0 0 7 req uires periodic assessm ents by the National R esearch that im provem ent is due to vehicle m odiications, cluding in Council of autom obile vehicle fuel econom y technolo gies. a m ore aggressive torq ue converter lock up and fuel cutoff Thus, follow- on com m ittees will be responsible respondfor during vehicle deceleration ( D . H ancock , General tors,M o ing to this legislative m andate, including the peri odic evalupersonal com m unications, Novem ber 3 0 , 2 0 0 7 ) . ation of P H EV s, EV s, and other technologies and these how The Oak R idge data did not include inform ationhe on t technologies can help m eet new fuel econom y standar ds. H onda A ccord, which was discontinued in 2 0 0A7 ccord . The has a m otor/ generator of 1 5 k W in m otoring m a ode and slightly higher 1 5 . 5 k W in regenerative m ode rm ( an, J . Ge H onda, personal com m unication, F ebruary 2 8The , 2 0 0 8 ). m otor generator has high- energy- density m agnets an intein TA BL E 6 . 4 R etail P rice Estim ates for V arious of Types rior coniguration. It also has lat wire windings that provide H ybrids P rojected to 2 0 2 5 ( using an R P E of 1 . 3 3 ) better pack ing density com pared to round wire. The NiM H 2 0 0 9 2 0 1 5 2 0 2 02 0 2 5 battery has 1 3 2 cells with a nom inal voltage and ergyenof V ehicle ($ ) ($ ) ($ ) ($ ) 1 4 4 V and 0 . 8 7 k W h, respectively ( Iijim nda calls a, 2 0 0 6 ) . H P rius- type power split 4 ,5 0 0 3 ,9 0 0 3 , 3 0 0the system 3 , 0 0 0 an integrated m otor assist. BA S / 1 2 V BA S / 4 2 V IS G 1 2 k W / 1 4 P rius- type P H EV S eries P H EV 4 0 H EV crossover ( V L arge S U V / pick

6 7 0 5 7 0 4 9 0 4 4 0 1 ,5 0 0 1 ,2 0 0 1 ,1 0 0 1 ,0 0 0 4 V 2 ,9 0 0 2 , 5 0 0 Plug-In 2 , 1 0Hybrids 0 2 ,0 0 0 1 0 ( L i- ion battery) 8 ,8 0 0 ,79 , 06 00 0 6 ,5 0 0 5 The fuel econom y ratings to plu g- in ( L i- ion battery) 1 3 ,0 0 0 1 01 0, 0 0 0 9 , 8 rules 0 0 for 8 ,assigning 9 being developed by S A E ( revis ion of 6 ) 6 ,9 0 0 6 ,0 0 0 5 ,hybrids 2 0 0 are 4 , currently 7 0 0 up ( V 8 ) 8 ,7 0 0 7 , 5 0 0 J 61, 47 010 1 )5 . , Thus 7 0 0 the com m ittee cannot predict tim at e what this

TA BL E 6 . 5 Com parison of F uel Econom y, F uel ion,Consum P erformpt ance, and P hysical S peciications rid of H andyb Com parable S I Engine- P owered V ehicles

A rchitecture

V olum e Trunk

P rius P rius/ Corolla 1 .3 3 P rius/ Cam ry 1 .0 7 H onda Civic Civic hybrid/ Civic S I 0 .8 3 Chevy Tahoe 4 W D Tahoe 4 W D H ybrid/ Tahoe 4 W D S I

F uel EP A EP A Test Consum ption Test Car ( m pg, com bined) ( gal/ 1 0 0 m i)

A cceleration Edm und’s ( Consum er R eports, m ph/ sec)M S R P to W 3 0 eight0 to 60 0 4 5 to 6 5 P rice

1 .6 4 2 .0 0

0 .6 1 0 .5 0

1 .1 3 0 .8 7

1 .0 6 1 .0 3

1 .0 7 1 .1 0

1 .0 5 1 .0 3

1 .5 1

0 .6 6

1 .0 0

1 .2 2

1 . 14 65

1 .2 2

N/ A

1 .5 3

0 .6 5

1 7. 0 0

0 . 9 61 . 1 5

1 .13 . 00

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

H Y B R ID P OWER TR AINS

9 5

the oficial fuel econom y rating of a speciic P H EV esign d builders, eq uipm ent suppliers, and governm entnizorga awill be. A t the tim e of this writing only two P Hhave EVbeen s tions, there rem ain signiicant problem s req uiring echnical t announced for production—the GM V olt, which is ex ctedpe and econom ic resolution, including the following: to have a 40- m ile range on battery alone, and the Toyota plug- in P rius, which will have a 1 2 - m ile allic range electr • H igher cost of fuel cells com pared to other ener gy and the ability to cruise at highway speeds under all electric converters, power.6 GM has announced that L G Chem of K orea will be • L ack of a hydrogen distribution infrastructure, supplying the V olt’s L i- ion battery. • Need for a low carbon source of hydrogen ( biom sas or water electrolysis using electricity produced with low em issions) , FUEL CELL VEHICLES • Need to dem onstrate acceptable durability and re liF uel cell vehicles have the potential to signiicant ly reability, and duce greenhouse gas em issions ( depending on how hydrogen • W eight and volum e of an on- board hydrogen storag e is produced) as well as U . S . dependence on im oil ported over tank siz ed for a range of 3 0 0 to 4 0 0 m iles. the long term . H owever, fuel cell vehicle technolog ies have technical challenges that are severe enough to convince the Because of these factors, the com m ittee does not pect ex com m ittee that it is unlik ely such vehicles will deployed be wide use of fuel cell vehicles before 2 0 2 5 . in signiicant num bers within the tim e horiz on is ofstudy. th A recent report ( NR C, 2 0 0 8 ) states that ollowunder the f FINDINGS ing set of very optim istic assum ptions, 2 m uel illion cellf vehicles could be part of the U . S . leet in 2 0 2 0 : Finding 6 .1 The : degree of hybridiz ation can vary from m inor stop- start system s with low increm ental and costs • The technical goals are m et and consum ers readil y m odest reductions in fuel consum ption ( i. e. , the st basic m o accept such vehicles. stop- start system s m ay have a fuel consum ptionitbene of • P olicy instrum ents are in place to drive their introduction. up to about 4 percent at an estim ated increm ental etailrprice • The necessary hydrogen production, supply, distribueq uivalent ( R P E) cost of $ 6 7 0 to $ 1 , 1 e0vehicle 0 ) to com plet tion, and fueling infrastructure is present. redesign ( e. g. , P rius) and downsiz ing of the Soline I gas en• Oil prices are at least $ 1 0 0 / barrel by 2 0 2 0 . gine at a high increm ental R P E cost ( $ 3 , 0 0 0 )toand $ 9 ,0 • F uel cell vehicles are com petitive on the basis of lifewith signiicant reductions in fuel consum ption. A signiicant cycle cost. part of the im proved fuel consum ption of production hybrid vehicles com es from vehicle m odiications such was lo A lthough the com m ittee agrees with that study’s- con rolling- resistance tires, im proved aerodynam ics, d the anuse clusions under these optim istic assum ptions, itieves bel of sm aller, m ore eficient S I engines. that achieving them is unlik ely. A lm ost everyOEM m ajor has a fuel cell vehicle program , and several haveeployed d Finding 6 .2:In the nex t 1 0 to 1 5 years, im provem ents in lim ited leets of ex perim ental vehicles. These leets invarihybrid vehicles will occur prim arily as a result ofreduced ably represent lim ited m ission, localiz ed ex perim ts, cityen costs for hybrid power train com ponents and im prove m ents buses, or postal vehicles, for ex am ple. Through erviews int in battery perform ance such as higher power per m s and as and presentations, the com m ittee can ind littledence evi that volum e, increased num ber of lifetim e charges, ider and w a com m ercially viable fuel cell light- duty vehicle will be allowable state- of- charge ranges. available in signiicant num bers by 2 0 2 0 . These J auto apane industry will not decide to pursue a com m ercial elopm dev ent Finding 6 .3 D: uring the past decade, signiicant advances program until 2 0 1 5 , thus m ak ing a 2 0 2 0date introduction have been m ade in lithium - ion battery technology. henW very dificult. The com m ittee conirm ed this target ecision d the cost and safety issues associated with L i- ionatteries b date with J apan’s NED O, J apanese academ ics, and OEM the s are resolved, they will replace NiM H batteries EV in H s and them selves. A ll current fuel cell vehicle research assum es P H EV s. A num ber of different L i- ion chem being istries are stored hydrogen as the fuel. The m onum ental dificul ty of studied, and it is not yet clear which ones will prove m ost providing the necessary hydrogen distribution infrastructure beneicial. is another factor m itigating against the presencefofuel cell vehicles in signiicant num bers by 2 0 2 0 . Finding 6 .4 Given : the high level of activity in lithium - ion F or fuel cells, in spite of hundreds of m illionsdollars of battery developm ent, plug- in hybrid electric vehicl es will having been devoted to their developm ent by vehicle be com m ercially viable and will soon enter at least lim ited production. H owever, im proving the cost- effectivene ss of P H EV s depends on the cost of fuel and whether icant signi 6 S ee http:/ / www. reuters. com / article/ pressR U elease/ S 2 id3 8 7 4 3 + 0 9 - S epreductions in battery cost are achieved. 2 0 0 9 + P R N2 0 0 9 0 9 0 9 .

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

9 6

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Grewe, T. H . , B. M . Conlon, and A . G. H olmining es. 2the0 General 0 7 . D e M otors 2 - m ode hybrid transm ission. S A E P 1aper - 0 22 07 03 7. -S 0A E International, W arrendale, P a. Iijim a, T. 2 0 0 6 . D evelopm ent of hybrid system 0 0 6 com for 2 pact sedan. S A E P aper 2 0 0 6 - 0 1 - 1 5 0 3 . S A E International, le, P a. W arrenda K alham m er, F . R . , B. M . K opf, D . H . dS M wan, . P V. W . P .alsh. R oan, an 2 0 0 7 . S tatus and P rospects for Z ero Em issions le Technology. V ehic R eport presented to A R B Independent Ex pert P pril anel,1 A 3 , S tate of California A ir R esources Board, S acram ento. Nelson, P . , K . A m ine, and H . Y om oto, lithium 2 0 0 7 - .ion A batteries dvanced for plug- in hybrid- electric vehicles. P aper present ed at 2 3 rd International Electric V ehicle S ym posium , D ecem ber, m , ACalif. nahei NR C ( National R esearch Council) . 2 0 0 8 . Transitions to A lternative TransFinding 6 .6A: lthough there has been signiicant progress in portation Technologies: A F ocus on H ydrogen. The tional Na A cadem ies fuel cell technology, it is the com m ittee’s opinion that fuel P ress, W ashington, D . C. cell vehicles will not represent a signiicant fraction of onR eilly, B. 2 0 0 7 . Battery Technologies. P resentation to the National R esearch road light- duty vehicles within the nex t 1 5 years. Council Com m ittee on the A ssessm ent of Technologies for Im proving L ight- D uty V ehicle F uel Econom y, October 2gton, 5 , W D .ashin C. R icardo, Inc. 2 0 0 8 . A S tudy of P otential essEffectiven of Carbon D iox ide REFERENCES R educing V ehicle Technologies. P repared for the. U Environm .S ental P rotection A gency. EP A 4 2 0 - R - 0 8 - 0 0 4- .C-Contract 0 6 - 0 No. 0 3 EP . A m ine, K . 2 0 0 7 . A dvanced high power chem H EVistries applications. for W ork A ssignm ent No. 1 - 1 4 . A nn A rbor, e atMhttp:/ ich./ www. A vailabl P resentation to the National R esearch Council Comtteemoni the A ssessepa. gov/ om s/ technology/ 4 2 0 r0 8 0 0 4 a. pdf.e 2A 9 ccessed , 2 0 0J un 9 . m ent of Technologies for Im proving L ight- D uty le F V uel ehicEconom y, R ousseau, A . , N. S hidore, R . Carlson, and. P2 . 0Nelson 0 7 . R esearch on Novem ber 2 7 , W ashington, D . C. P H EV battery req uirem ents and evaluation ofrototypes. early p P aper A nderm ann 2 0 0 7 . L ithium - ion batteriesectric for hybrid vehicles: el Opporpresented at the A dvanced A utom otive Battery Confer ence, M ay 1 7 , tunities and Challenges. P resentation to the Nation al R esearch Council L ong Beach, Calif. Com m ittee on the A ssessm ent of Technologies for roving Im Lp ightTate, E. D . , M . O. H arpster, and P . J . S The avagian. electriication 2 0 0 9 of. the D uty V ehicle F uel Econom y, October 2 5 , W D ashington, . C. autom obile: F rom conventional hybrid, to plug-brids, in hy to ex tendedCalifornia A ir R esources Board. 2 0 0 9 . D riveClean. vailable at A http:/ / www. range electric vehicles. S A E International 1 ( A :1 5pril) 6 -1 6 6 . driveclean. ca. gov. A ccessed J une 2 9 , 2 0 0 9 . Tesla M otors, Inc. 2 0 0 9 . Tesla R oadster S Apecvailable S heet.at http:/ / F ushik i, S . , and B. W im m er. 2 0 0 7 . Toyota. P erspectives P resentation from www. teslam otors. com / display_ data/ teslaroadster_ sheet. spec pdf. A cto the National R esearch Council Com m ittee on the ssessm A ent of J une 2 9 , 2 0 0 9 . Technologies for Im proving L ight- D uty V ehicle F uel Econom y, Novem cessed Transm ission Technology International. 2 0 0 8 . htZ speed F eighybrid. ber 2 7 , W ashington, D . C. S eptem ber, p. 1 0 .

Finding 6 .5 The : practicality of full- perform ance battery electric vehicles ( i. e. , with driving range, trunk space, volum e, and acceleration com parable to those ofernal int com bustion- powered vehicles) depends on a battery ostc break through that the com m ittee does not anticipate within the tim e horiz on considered in this study. H owever, it is clear that sm all, lim ited- range, but otherwise full-rm perfo ance battery electric vehicles will be m ark eted within hatt tim e fram e.

Toyota Toyota Toyota Toyota Toyota Toyota Toyota Toyota Toyota F ord F ord F ord F ord F ord F ord S aturn S aturn S aturn S aturn S aturn S aturn H onda H onda Nissan Nissan M az da M az da M az da M az da M az da M az da M ercury M ercury M ercury M ercury M ercury M ercury

M ak e

M odel

D rive

Trunk

City

Com b.

EP A F uel Econom y V olum e( unadjusted m pg) H wy

4 .4 NA NA NA 1 0 .7 1 0 7 .9 NA 9 .4 6 .6 7 .3 1 0 .9 NA NA 1 1 .7 1 0 .1 7 .6 8 .1 NA NA NA 1 0 .7 1 0 7 .9 NA NA NA 1 0 .7 1 0 7 .9

1 0 .6 9 .9 9 .6 1 1 .4 8 .5 9 .6

3 .8 3 .6 3 .7 4 .1 3 .5 3 .7 7 .1 NA NA NA 4 .1 3 .3 3 NA 3 .4 2 .8 4 .2 NA NA 4 .4 3 .6 3 .1 3 .2 NA NA NA 4 .1 .3 3 NA NA NA 4 .1 3 .3 3

8

H Y B R ID P OWER TR AINS co ntinu ed

$ $ 2 9 ,0 5 0 $ 2 2 , $ 1 6 ,1 5 $ 2 0 ,1 9 $ 1 3 , $ 2 6 $ 2 0 ,1 9 $ 2 4 ,2 1 5 NA $ 2 9 ,6 4 NA $ 2 1 ,6 4 5 NA $ 2 4 ,4 6 5 3 9 5 .8 $ 3 1 6 .4 $ 2 3 ,3 9 5 .2 $ 2 6 ,2 1 NA $ 2 6 ,3 2 6 .9 $ 2 2 , 4 .3 $ 2 7 , $ 2 8 ,1 6 0 NA $ 2 3 ,2 8 NA $ 2 6 ,4 3 2 3 , 6 57 0. 3 $ 6 $ 1 6 ,3 $ 2 6 , 6 45 .04 5 $ 1 9 ,9 NA $ 2 8 ,1 7 NA $ 2 1 ,7 9 0 NA $ 2 3 ,0 5 5 9 25 5. 8 $ 2 9 , 6 .4 $ 2 3 ,5 4 5 5 .2 $ 2 4 ,8 0 5 NA 0 $ 3 0 ,0 9 NA $ 2 2 ,6 5 0 NA $ 2 3 ,6 6 0 1 , 8 45 0. 8 $ 3 6 .4 $ 2 4 ,4 0 5 .2 $ 2 5 ,4 1

3 4 , 75 0 0 5 .1 6 .2 5 .9 6 6 .9 1 5 05 . 1 6

P rice

Edm und’s M S R P 4 5 to 6 5 m ph, sec.

8 .2

3

3 .4

0 to 6 0 m ph, sec.

A cceleration ( Consum rts) er R epo

Car W 0eight m ph,0 sec. to 3

EP A Test

P erform ance of P roduction H es from ybrid V2 ehicl 0 0 9 CA F E Certiication D ata

H ighlander H ybrid 4 W D NA 3 5 3 5 3 5 5 0 0 0 H ighlander 4 W D NA 2 1 2 5 3 1 4 7 5 0 S plit P rius F W D 1 6 6 7 6 6 6 5 3 2 5 0 Corolla F W D 1 2 3 5 4 0 4 9 2 8 7 5 Cam ry F W D 1 5 2 7 3 3 4 4 3 7 5 0 Y aris F W D 1 3 3 7 4 2 4 9 2 6 2 5 S plit Cam ry H ybrid F W D 1 1 4 4 4 6 4 8 4 0 0 0 Cam ry F W D 1 5 2 7 3 3 4 4 3 7 5 0 Cam ry F W D 1 5 2 5 43 00 3 8 7 5 3 .3 S plit Escape H ybrid F W D NA 4 5 4 4 4 3 4 0 0 0 Escape F W D NA 2 6 3 0 3 9 3 6 2 5 Escape F W D NA 2 3 2 7 3 6 3 6 2 5 S plit Escape H ybrid 4 W D NA 3 7 3 7 3 7 4 2 5 0 Escape 4 W D NA 2 4 2 8 3 5 3 8 7 5 Escape 4 W D NA 2 2 2 6 3 3 3 8 7 5 P arallel A ura H ybrid F W D 1 6 3 3 3 9 4 8 NA A ura F W D 1 6 2 8 3 4 4 7 4 0 0 0 A ura F W D 1 6 2 1 2 6 3 6 4 0 0 0 V ue H ybrid F W D NA 3 2 3 7 4 5 4 0 0 0 V ue F W D NA 2 4 2 8 3 7 4 0 0 0 V ue F W D NA 2 1 2 5 3 3 4 2 5 0 P arallel Civic H ybrid F W D 1 0 5 5 5 9 6 5 3 1 2 5 Civic F W D 1 2 3 3 3 9 5 1 3 1 2 5 P arallel A ltim a H ybrid F W D 1 0 4 7 4 7 4 7 3 7 5 0 A ltim a F W D 1 5 2 9 3 4 4 3 3 5 0 0 S plit Tribute H ybrid F W D NA 4 5 4 4 4 3 NA Tribute F W D NA 2 6 3 0 3 9 NA Tribute F W D NA 2 3 2 7 3 6 NA S plit Tribute H ybrid 4 W D NA 3 7 3 7 3 7 NA Tribute 4 W D NA 2 4 2 8 3 5 NA 3 Tribute 4 W D NA 2 2 2 6 3 3 NA S plit M ariner H ybrid F W D NA 4 5 4 4 4 3 NA M ariner F W D NA 2 6 3 0 3 9 NA M ariner F W D NA 2 3 2 7 3 6 NA S plit M ariner H ybrid 4 W D NA 3 7 3 7 3 7 NA M ariner 4 W D NA 2 4 2 8 3 5 NA M ariner 4 W D NA 2 2 2 6 3 3 NA

S plit

Type

TA BL E 6 . A . 1

ANNEX

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

9 7

Chevrolet Chevrolet Chevrolet L ex us L ex us L ex us L ex us L ex us L ex us L ex us L ex us L ex us Chevrolet Chevrolet Chevrolet Chevrolet Chevrolet Chevrolet Chevrolet Chevrolet Chevrolet Chevrolet Chevrolet GM C GM C GM C GM C GM C GM C GM C GM C GM C GM C GM C D odge D odge Chrysler Chrysler Cadillac

S plit

S plit

S plit

S plit

S plit

S plit

S plit

S plit

S plit

S plit

S plit S plit

S plit

S plit

D rive

Trunk

City

Com b.

H wy

7 .9 NA NA NA 9 .6 9 NA NA NA NA NA 7 .9 NA 7 .4 NA 7 .4 NA

$ 2 5 ,5 5 5 7 5 .1 NA NA NA 4 .6 NA NA 5 5 0 3 .9 NA NA 4NA5 5 NA NA 5 3 ,52 . 65 0 5 .7 8NA, 0 2 0 NA NA $ 4 1 ,1 7 0 NA 5 .1 NA NA NA 5 .5 5 .7 NA NA NA NA NA 5 .1 NA 5 .2 NA 5 .2 NA1 3 5

$ 2 1 ,6 0 NA NA $ 3 7 NA NA $ 3 9

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

$ 2 6 ,9 1 5 $ 4 1 ,5 4 NA $ 3 0 ,0 $ 4 5 ,0 4 NA $ 4 5 ,2 7 0 NA $ 7 3 ,

$ 3 0 ,0 6 $ 5 0 ,9 P rem ium $ 3 9 ,9 7 0 $ 5 3 , $ 4 1 ,7 6 $ 3 8 ,3 9

$ 2 6 ,9 1 5

$ $ 4 5 , $ 1 $ 5 0 , P rem ium $ 3 9 ,3 1 5 $ $ 4 1 ,0 2 5 $ 3

P rice

Edm und’s M S R P 4 5 to 6 5 m ph, sec.

6 .9 1 0 . 9 .4 8 .1 NA NA NA 7 .4 NA 4 .8 5 .9 NA NA NA NA NA 9 .6 9 NA NANA NA

0 to 6 0 m ph, sec.

A cceleration ( Consum rts) er R epo

Car W 0eight m ph,0 sec. to 3

EP A Test

9 8

S plit

M odel

Type

P arallel

M ak e

Oficial EP A V olum e( unadjusted m pg)

M alibu H ybrid F W D 1 5 3 3 3 9 4 8 3 8 7 5 3 4 .1 M alibu F W D 1 5 2 7 3 3 4 3 3 7 5 0 3 .4 M alibu F W D 1 5 2 3 2 8 4 0 NA 3 R X 4 0 0 h H ybrid 2 W D NA NA NA NA NA NA R X 3 5 0 2 W D NA 2 0 2 2 2 5 4 2 5 0 NA R X 3 5 0 2 W D NA 2 0 2 2 2 5 NA NA R X 4 0 0 h H ybrid 4 W D NA NA NA NA NA 2 .9 R X 3 5 0 4 W D NA 2 2 2 6 3 2 4 5 0 0 NA R X 3 5 0 4 W D NA 2 2 3 2 2 6 NA 2 .7 7 .3 GS 4 5 0 h H ybrid R W D 9 2 8 3 1 3 5 4 5 0 0 2 .5 GS 3 5 0 R W D 1 3 2 4 2 8 3 7 4 0 0 0 NA L S 6 0 0 hL A W D 1 2 2 5 2 7 3 0 5 5 0 0 NA Tahoe H ybrid R W D NA 2 7 2 8 3 0 6 0 0 0 NA Tahoe R W D NA 1 5 1 9 2 7 6 0 0 0 NA Tahoe R W D NA 1 7 2 0 2 7 5 5 0 0 NA Tahoe H ybrid 4 W D NA 2 7 2 8 3 0 6 0 0 0 3 .9 Tahoe 4 W D NA 1 5 1 8 2 6 6 0 0 0 3 .4 S ilverado H ybrid R W D NA 2 7 2 8 3 0 NA NA S ilverado R W D NA 1 7 2 1 2 7 5 5 0 0 NA S ilverado R W D NA 1 8 2 1 2 7 5 0 0 0 NA S ilverado H ybrid 4 W D NA 2 7 2 8 3 0 NA S ilverado 4 W D NA 1 7 2 0 2 7 5 5 0 0 S ilverado 4 W D NA 1 8 2 1 2 7 5 2 5 0 3 Y uk on H ybrid R W D NA 2 7 2 8 3 0 NA NA Y uk on R W D NA 1 5 1 9 2 7 NA NA Y uk on R W D NA 1 7 2 0 2 7 NA NA Y uk on H ybrid 4 W D NA 2 7 2 8 3 0 NA 3 .9 Y uk on 4 W D NA 1 7 2 0 2 7 NA 3 .4 S ierra H ybrid R W D NA 2 7 2 8 3 0 NA NA S ierra R W D NA 1 7 2 1 5 5 20 70 NA NA S ierra R W D NA 1 8 2 1 2 8 NA NA S ierra H ybrid 4 W D NA 2 7 2 8 3 0 NA NA S ierra 4 W D NA 1 7 2 0 2 7 NA NA S ierra 4 W D NA 1 8 2 1 2 7 6 0 0 0 3 D urango H ybrid 4 W D NA 2 5 2 7 3 0 NA NA D urango 4 W D NA 1 7 2 0 2 6 NA 2 .8 A spen H ybrid 4 W D NA 2 5 2 7 3 0 NA NA A spen 4 W D NA 1 7 2 0 2 6 NA 2 .8 Escalade H ybrid 2 W D NA 2 7 2 8 3 0 NA NA

Continued

TA BL E 6 . A . 1

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

7 Non-Engine Technologies

INTRODUCTION This chapter focuses on reducing fuel consum ption iwth non- power- train technologies. These technologies fect af engine perform ance either directly or indirectly in a m anner that reduces fuel consum ption. F or ex am ple, icant a signi portion of this chapter discusses the state of readiness, cost, and im pact of reducing vehicle m ass. R educing m ass reduces the energy necessary to m ove a vehicle, and thus reduces fuel consum ption. The com plex ity of substit uting advanced, lightweight m aterials affects the redesig n of a part or a subsystem , com ponent m anufacturing d( inclu ing tooling and production costs) , and joining, andraises interface issues that m ix ing different m aterials n pose. ca The term material su b stitu tio oversim n pliies the com plex ity of introducing advanced m aterials, because seldom does one part change without changing others around it. A dvanced lightweight m aterials show great prom or ise f reducing m ass throughout a vehicle’s body structureand interior. L ow- rolling- resistance tires and reductio n of aerodynam ic drag are also discussed as technologiesthat can lower tractive force and result in reduced fuel consum ption. Im provem ents in energy- drawing devices such s aira conditioner com pressors and power steering can redu ce fuel consum ption either by electriication or by im provin g their eficiency. New transm issions with m ore gears ort tha are continuously variable im prove power train eficiency . A ll these options either reduce the dem and for power om fr the engine or enable operating the engine at a m ore efi cient point to reduce fuel consum ption.

cost- effective reductions in fuel consum ption. Thes e will be considered in som e detail below. Aerodynamics

A s discussed in Chapter 2 , the force req uired ercom to ov e drag is represented by the product of the drag coeficient, the frontal area, and the sq uare of speed. The actu al form ula is F = ½ Cd A V 2 where A is the vehicle frontal , V area is velocity, and Cd is the drag coeficient. Cd typically ranges from about 0 . 2 5 to 0 . 3 8 on production vehicles depends and on several factors with the prim ary inluence com ing from vehicle shape and sm aller inluences from other ors, fact such as ex ternal m irrors, rear spoilers, frontal inlet reas, a wheel well covers, and the vehicle underside. V ehiclesth wihigher Cd values ( greater than . 3 0 ) m ay be able to reduce the Cd by up to 1 0 percent at low cost without affecting the vehicle’s interior volum e. In trying to reduce fuel consumon,pticertain vehicles achieved very low drag coeficients, for exam ple, GM ’s EV 1 had a Cd of 0 . 1 9 , and the third- generation P rius has a Cd of 0 . 21 5In. the com m ittee’s judgm ent a Cd of less than 0 . 2 5 would req uire signiicant changes t could tha include the elim ination of outside rear view m irror s, total enclosure of the car underbody, and other m odiicati ons that m ay be very costly. V ehicles that ex ist today with a low Cd ( below 0 . 2 5 ) are usually specialty vehicles ( e. g. , sports cars and high- m ileage vehicles lik e the Ps) riu . The 2 0 1 0 M ercedes E- class is the only productione with vehicl a Cd as low as 0 . 2 5 . H owever, this is a lux suryvehicle clas and retails for $ 5 0 , 0 0 0 ( or m ore) . S om ncurred e costs are i from incorporating aerodynam ic features such as the integrated front spoiler, an option that m ay not be pos sible for NON-ENGINE TECHNOLOGIES CONSIDERED IN THIS lowercost vehicle classes. F urther reducing Cd for lowerSTUDY cost vehicles is ex pensive and perhaps beyond a point of The com m ittee considers car body design ( aerodynam cs i dim inishing returns. V ehicles with higher Cd ( truck e. g. , s, and m ass) , vehicle interior m aterials ( m ass) , vehicle , tires accessories ( power steering and heating, ventilatio n, and v1 - electricgm - e car. air conditioning [ H V A C] system s) , and transm as issions1 S ee http:/ / www. greencar. com / articles/ 2 0 - truthsphp and http:/ / pressroom . toyota. com / pr/ tm s/ ll-toyota/ new- priusa reveal. areas of signiicant opportunity for achieving near-term , aspx , respectively.

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vans, and box - lik e vehicles such as the S cion and lex F) can reduce Cd, although vehicle functionality is dim ini shed. If the functionality is com prom ised, then the vehicle’ s appeal to the consum er would be reduced. A s noted above, the aerodynam ic drag is the product of the drag coeficient Cd, the vehicle frontal area, nad speed. R eduction in the frontal area, reducing vehicle siz e, and lower speed lim its would also im prove fuel consum ion;pt however, ex ploring these options is outside the com m ittee’s statem ent of task . Car Body Design and Interiors

ex am ple, for som e non- structural applications, l becom stee es cost com petitive vis- à- vis plastic at around 5 0 units. ,0 0 0 Two k ey strategies for achieving m ass reduction are changing the design to req uire less m aterial, orbstituting su lighter- weight m aterials for heavier m aterials.um A ing ss that the car siz e is essentially ix ed, there are design techniq ues that can reduce m ass. S everal different body architectures are described below. M aterial substitution relies onplacing re a heavier m aterial with a lighter one while m aintaini ng perform ance ( safety and stiffness) . F or ex am ple, strength highsteel can be substituted for m ild steel ( and theref ore a thinner gauge can be used) , alum inum can be substitutedsteel, for plastic can be substituted for alum inum , and m ium agnescan be substituted for alum inum . It is often a m isnom to refer er to this as m aterial substitution. The part ( or subs ystem ) often has to be redesigned, and the fabrication process may change and the assem bly process m ay be different. In fact, the m aterial cost differential m ay be insigniicant relative to the costs associated with the changes in fabrication and assem bly.

Optim iz ed car body design focuses on a balance betw een structural stiffness, noise/ vibration/ harshness ( NV H ) , safety ( crashworthiness) , com fort ( space) , and m ass. ’s priToday ority of reducing fuel consum ption places an em phas is on m ass reduction, with the assum ption that other orm perf ance criteria will not be unduly com prom ised. V ehicle ss can m a be reduced without com prom ising siz e, crashworthine ss, and NV H , although counterm easures are often req d touire Body Design and Material Selection restore NV H perform ance when m ass is reduced. The m ajority of vehicle m ass can be attributedhe to body t The great m ajority of vehicles produced today are niu structure, closure panels ( doors, hood, and deckd) li, interior body design. The unibody design is a construction techniq ue seating and trim com ponents, glass, power trainponents com that uses the internal parts as the principal load-bearing ( engine, transm ission, etc. ) , and the chassiss,( ax wheels, le structure. W hile the closure panels ( doors, hood, nd deck a brak es, suspension, etc. ) . S teel, cast iron, einforced iber/ r lid) provide im portant structural integrity to the body of the com posites, glass, and alum inum have been the ant dom in vehicle, the outer sk in panels, deined as the m etal outer m aterials for these com ponents, with steel accounti ng for panels on the entire autom obile that are painted an d visthe m ajority of m ass. Estim ates for the am ount heseof t ible to the consum er, do not. This design has repla ced the m aterials in today’s average, high- volum e vehicles are listed traditional body- on- fram e design prim arily because it is a in Table 7 . 1 ( Carpenter, 2 0 0 8 ) . The typical e vehicle baselin lighter. Body- on- fram e designs, where an independen t body used for com parison is described as a 3 , 6 0 0 - llb year m ode structure ( with its own structural integrity) sitson top of a 2 0 0 9 com parable to a Toyota Cam ry or Chevrolet bu. M aliseparate fram e ( with its own structural integrity) still , prevail H igh- volum e vehicle m anufacturing is generally ci-asso on som e heavier vehicles such as pick up truck s and larger ated with the production of m ore than about 1 0 0 vehicles ,0 0 0 S U V s because of its overall superior strength and tiffness. s per year ( although som e m ight say 5 0 , 0 0 0 )m. Le owAvolu nother design, the space fram e, was recently devel oped m ight be under 2 5 , 0 0 0 vehicles per year. This portant is im to accom m odate alum inum . The form ing and joining of because different m aterials becom e cost com petitive at alum inum cannot easily or cheaply be replicatedainsteel different volum es. H igher- cost m aterials ( com s, aluposite unibody design. A typical space fram e is com posed f ex om inum , and m agnesium ) becom e m ore cost atcom petitive truded m etal connected at the ends, which are refer red to as lower volum es because the form ing tools in m ost es cas have nodes. Both the unibody and the space fram e have ang“h on” a lower investm ent cost offsetting the higher m ial atercost. panels where the sk in panels have little to no structural load. S teel req uires high- cost form ing tools but haswer a lom ateA inal design architecture, the m onocoq ue, relies n theo rials cost, m ak ing steel com petitive at highermvolu es. F or outer sk in surface as a principal load- bearing surf ace. The

TA BL E 7 . 1 M aterial

D istribution of M aterials in Typical cle ( e.Vg.ehi , Toyota Cam ry and Chevrolet M alibu) Com m ents

A pprox im ate Content in Cars Today, by W eight ( percent)

Iron and m ild steel U nder 4 8 0 M pa 5 5 H igh- strength steel ≥ 4 8 0 M pa ( in body structure) 1 5 A lum inum No alum inum closure panels; alum inum block engine and head and wheels 1 0 P lastic M iscellaneous parts, m ostly interior ight trim lenses, , l facia, instrum ent panel 1 0 Other ( m agnesium , titanium , rubber, etc. ) Mousiscellane parts 1 0

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m onocoq ue is seen in very low volum es because there are few applications where it is structurally and econom ically viable. Generally, these three designs are associated with the following m aterials:

10 1 hydro- form ed sheet m etal. The use of tubes andr lase blank s can m ak e m ore optim al use of m etal ( steel or alum inum ) and result in less m ass in the structure without com prom ising design criteria. These m sethod m ay increase or decrease costs depending on the application.

• U nib o—steeldy based structure ( m ostly steel stam pings) usually with steel sk in panels but som etim es plastic or alum inum sk in panels. This design has high M ost steel and m ix ed- m aterial vehicles ( e.and g. , steel investm ent ( engineering and tooling) costs and is e- d alum inum ) today are unibody, and alum inum - intensive signed for high volum e. vehicles tend to be space fram e designs, but these are low • Sp ace frame—usually an alum inum - based structure volum e due to cost. The unibody design was develope d ( alum inum castings, ex trusions, and sheet) .sign This de prim arily for steel, and the conventional vehicleoday t is is less com plex than the unibody and has lower inve stcom posed of about 6 5 percent steel ( both m ildigh and h m ent costs, which are typically offset by higher m terial a strength) . V arious com ponents of a unibody can have altercosts. Because of the high m aterial costs ( that are varinative lightweight m aterials, including high- streng th steel, able with volum e) , this is typically a low- volum esign. ed polym ers/ com posites, and alum inum directly uted substit on • Mo no co —reinforced q u e resin/ com posite body struc- a part- by- part basis to help reduce m ass on a lim ed basis. it ture using the sk in to bear loads. Today, this arch itecS heet m olding com pound ( S M C plastic) bodyepanels ar ture is uncom m on for passenger autom obiles and m ore som etim es used for fenders or ex terior closure ls pane to com m on for aircraft or ships. save weight, and in the case of low- volum e vehicles , to save costs. The ability to substitute alternative m ateri als, however, The space fram e and m onocoq ue structures are associ can be lim ited because of form ing ( part shape)ning, , joi and ated today with niche vehicle m ark ets, whereas unibody the interface issues between m ix ed m aterials. S teel bodyuni with its steel- based structure is com m on ( perhaps oundf in designs can accom m odate polym er/ com posite orum alum in m ore than 9 9 percent of today’s autom obiles) .design These closure panels because these parts can be easily isolated from approaches differ from the body- on- fram e design t istha the rem ainder of the structure since they are fastened onto the well suited for heavier “work ing” vehicles lik e tru ck s and structure. M any unibody steel- based vehicles m nade North i S U V s. Body- on- fram e readily achieves all the desired design A m erica have alum inum hoods and deck lids, but steel doors. criteria, ex cept that it is heavy because of the rge la fram e H oods and deck lids are sim pler designs than doors ( they are com ponents. latter and have fewer parts, and therefore are lessex pensive and less com plex to switch over to alum inum ) doors . S teel could also be converted to alum inum in m any cases, as is Reducing Mass Using Alternative Materials often done in Europe, but in North A m erica their z esiand There are several m ethods to m ak e steel structures lighter, geom etry would m ak e this conversion relatively nsive. ex pe regardless of their design construction: The m ass savings by introducing high- strength steel results from the ability to down- gauge the thick ness over m ild • S ubstitute higher- strength steel for lower- stren gth steel while m aintaining the sam e strength as theickth er steel. H igher- strength steel can be down- gauged ( m adem ild steel part. D own- gauging reduces stiffness, d soanthis thinner) . There are, however, form ing and joining is not a solution in som e cases where stiffness is im portant. issues with higher- strength steel that lim it where it can A lso, as the strength of steel increases, its abili ty to be be applied, and down- gauging can reduce the abilityto form ed into different shapes is reduced ( its allowa ble percent m eet stiffness criteria. elongation is reduced) . This reduced form abilitysoallim its • S ubstitute sandwich m etal m aterial for conventio nal where high- strength steel can be applied. The outsi de panels steel. S andwich m aterial has layers of steel ormalui( sk in panels) on a unibody are predom inantly nonructural st num ( usually three) , often with the internal layer in and subject to dents, thus also lim iting the abilit y to downthe form of honeycom b or foam . Other layered m ategauge these panels. The tools that form high- streng th steel rials can include bonded steel with plastic/ polym s.er parts cost m ore, req uire greater m aintenance becaus e they This cladding m aterial can achieve high stiffnessnd a are subject to wear, and req uire greater form ingessures pr strength levels with low m ass. S andwich m aterial is in production. In m ost cases, high- strength steel artsp cost light, is very stiff, and can be form ed for m any rts.pa m ore than com parable m ild steel parts. New, advance d highOn the downside, joining it to other parts can be difistrength steels are being developed to give high- strength cult, its availability is lim ited today, and itex is pensive steel greater form ability and weldability. These vanced ad to produce. high- strength steels, ex pected to be available with in a few • Introduce new steel designs that are available, such as years, can reduce m ass on som e com patible parts around by with laser welded blank s and hydro- form ed tubes or 3 5 percent. This is achieved by using high- strength steel to

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reduce part thick ness by 3 5 percent ( e. g. , replacin g 1 . 8 - m m greater supply of the base m aterial of P M C. One ertex stated p thick m ild steel with 1 . 2- m m - thick high-eel) strength . that st carbon iber will see wider use in the future, but prim arF actors such as part geom etry and subsystem stiffne ss can ily on lower- volum e ( fewer than 1 0 0 , 0 0 0 rvehicles year) , pe lim it viable applications of high- strength steel or constrain higher- perform ance vehicles ( Carpenter, 2 0 0 8 ) . the reduction in thick ness. The cost differential ( by pound) varies signiicantl y for A n aggressive approach to introducing alum inum into alternative m aterials. H igh- strength steel m st ight double co the structure m ay dictate a totally different bodydesign the price of m ild steel ( $ 0 . 8 0 versus $ 0 .nd) 4 0, and per pou approach, such as shifting from a unibody to a spac e fram e alum inum m ight cost four or ive tim es that of( per steel structure. The space fram e design has been developed pound) . Other m aterials such as m agnesium and iumtitanare recently for alum inum - intensive structures. The ucture str also ex pensive and have volatile price luctuations. is com posed of alum inum castings, ex trusions,heet. and s It is im portant to recogniz e that the com parison differof This design is lighter than a com parable steel desi gn and ent m aterials is com plicated by m any factors, gma cost ak in is in production today, but is used only on lower- ovlum e, analysis dificult. Tooling costs and parts fabrication costs higher- end vehicles because of its high cost. Intro ducing an differ signiicantly for different m aterials. alum inum - intensive structure would necessitate m a coplete vehicle redesign, req uiring several years at ex trem ely high • The am ount of m aterial ( pounds) needed by ghtthe li developm ent costs ( see the product developm ent ess proc weight m aterial is different from the incum bent terial. m a discussion in the section “Tim ing Considerations fo r Intro• Because of part fabrication, the optim al design with ducing New Technologies” below in this chapter) . the lightweight m aterial m ay be very different from P olym er- m atrix com posites ( P M Cs) are beginning the to design of the original part. F or ex am ple, som e be introduced into higher- volum e vehicles. V iable ptions o steel parts cannot be form ed ex actly the sam e out f o for P M C are for it to be reinforced with glass iber s, natualum inum because of form ability constraints. A lso, ral ibers, or carbon iber to give it strength. Glass- and if you substitute a m aterial that is cast ( m agnesiu m ) natural- iber- reinforced P M Cs are lower cost than rbon ca instead of stam ped ( steel) , the form ing cost and e th iber, but they have less strength. S ince they incur lower cost, part design are different. it is lik ely that these applications will be seen on higher• The tooling to form the alternative m ateriallikis ely to volum e vehicles before there is signiicant use ofarbon c iber be different than the tooling for the incum bent me- at com posites. Carbon iber is a prom ising lightweight m aterial rial, and m ay cost m ore or less. for m any autom otive com ponents. M uch lik P e plastic, M C • The processing ( part fabrication) process willikl ely can be m olded into com plex shapes, thus integrating several run differently, and m ay operate m uch slower than steel or alum inum parts into a single P M C part reduces that that for the incum bent m aterial ( e. g. , m olding uch is m com plex ity and tooling costs. Conservative estim ates are that slower than stam ping, som etim es by a factor of 1 0 ) . carbon iber P M C can reduce the m ass of a steelcture stru by 4 0 to 5 0 percent ( P owers, 2 0 0 0 ) . Both th anditsitsstreng U S CA R and the U . S . D epartm ent of Energy continue t stiffness can ex ceed that of steel, m ak ing it to easy substitute research reducing body m ass by substituting new merials, at for steel or alum inum while offering eq ual or rbette structural such as high- strength steel, advanced high- strength steel, perform ance. The greatest challenges with P M C ost are c alum inum , m agnesium , and com posites for current erials. m at and carbon iber availability. A lso challenging isonnectc The m aterial industries also conduct signiicant res earch to ing com posite parts with fasteners, which has delay ed the advance new m aterials ( for ex am ple, through the o- A S teel ut introduction of the latest Boeing 7 8 7 J et. P artnership, the A m erican Iron and S teel Institute, the A luThe price of carbon iber is ex trem ely volatile, hwit m atem inum A ssociation, and the A m erican Chem il) istry . Counc rial cost typically in ex cess of $ 1 0 / lb. Carbon r ex ibeceeds Increased costs for lighter and stronger parts result from the cost of steel and alum inum by approx im ately fold2and 0 higher m aterial costs and higher costs for com ponen t fabrica7 - fold, respectively. S teel and alum inum can e form also bed tion and joining. Estim ates for the body- m ass reduc tion that with high- speed stam ping, which is m uch less costly than can be achieved in the near term vary from 1 0 ntperce ( with form ing P M C, which typically involves a fairly autoslow m ostly conventional and high- strength steels) to percent 5 0 clave process. R esearch at Oak R idge National Latory abor ( with a m ostly alum inum / com posite structure) greater . Even ( OR NL ) is aim ed at developing lignin- based carbon ber to i reductions are feasible, but these req uire very exensive p and help reduce m aterial cost and im prove supply ( Com re etpe aggressive use of alum inum , m agnesium , and com e posit al. , 2 0 0 1 ) . This research in conjunction with F reedom the Car structures involving m aterials such as carbon iber. program at the U nited S tates Council for A utomR otive esearch ( U S CA R ) indicates that the price of carbon ber hasi Non-Body Mass Reduction to fall to $ 5 to $ 7 per pound ( about 5 0 percent) fore it can be be cost com petitive for high- volum e autom obiles ( Carpenter, V ehicle interiors also offer opportunities to reduce vehicle 2 0 0 8 ) . L ignin- based carbon iber will also help re aensu m ass. S om e opportunities can be im plem ented tle for lit

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cost, whereas others entail signiicant costs. F orx eam ple, num bers, ” and so original eq uipm ent tires tend ave tolower h com posite- intensive instrum ent panels, recycledting sea rolling resistance than consum er- replaced tires bec ause m aterials, and lighter- weight trim panels can reduc e m ass typical values for the coeficient of rolling resistance ( or) by tens of pounds at virtually no cost. H owever, lik un e the values differ between them ( NR C, 2 0 0 6 ) . ents Thisan repres car body for which the consum er cannot easily detec t what interesting value tradeoff. The OEM s are m ore ested inter in m aterials are used, the interior is aestheticallyritical c and getting low- rolling- resistance tires to show im prov ed fuel closely scrutiniz ed by the consum er. Costs m ayncurred be i econom y, and people buying replacem ent tires arerem o by covering over the appearance of som e parts.There are interested in low cost and durability. Therefore the total opq uality concerns, such as it- up of panels, part ture, tex and portunity for fuel consum ption reduction is deinedby the appearance issues that constrain interior cock pit design alfraction of the tires on the road that falls into each category. ternatives. S om e isolated com ponents can havereduced m ass Education of the public on the subject of low- rolling- resiswith m aterial substitution such as headlam ps ( with new tance tires for replacem ent tires and the continued introducresins) and wheels ( with new alum inum grades)actuthat tion of tire pressure m onitoring system s, which discussed is ally enhance aesthetics but often increase cost. Non- visual below, m ay help im prove in- use perform ance of fortires fuel parts, however, also present an opportunity, suchsaseat belt consum ption reduction. reinforcem ents, seating fram es/ brack ets, andllire panels. wa There are perform ance tradeoffs involving tires tha t tire M ost non- structural applications that can be lightweighted m anufacturers consider during design and m anufactur ing. with plastic already have been. Glass- reinforced sh eet m oldThese tradeoff variables include, for ex am ple, dtrea com ing com pound ( S M C) is low cost and inex pensive orm tobut f pound, tread and undertread design, bead/ sidewall,belts, lack s suficient strength to replace m ost structural applicacasing, and tire m ass. Im portant tire perform riteria ance c tions responsible for m uch of the weight. affected by design and m anufacturing include rollin g resisIsolated com ponents on the vehicles are also candid ates tance, tire wear, stopping distance ( stopping dista nce or grip for alum inum , m agnesium , or advanced high-steel strength can be evaluated over different surfaces, such as wet or dry) , substitution, such as wheels, engine cylinder heads, susand cornering grip. W ear and grip are closely corre lated to pension arm s, transm ission cases, brak e calipers, teerings tread pattern, tread com pound ( e. g. , softer comdspoun grip k nuck les, and engine block s, although m any OEM e s hav better but wear faster) , and footprint shape. already m ade these substitutions, especially in cyl inder The im pact of em phasiz ing one perform ance objective block s and heads. A lum inum heads are m ore com an m on ( such th as low rolling resistance) over other perform ance alum inum block s because of perform ance issues e block in th , criteria is inconclusive. S om e studies have shown hat ttires but other m aterials including hybrid m aterials (h bot alum iwith low rolling resistance do not appear to com pro m ise num and cast iron) are being applied to the blockA s. n even traction, but m ay wear faster than conventional es. tir A nm ore aggressive approach to introducing alum inum into the other study in 2 0 0 8 by Consum ers U nion and sum ed m ariz structure itself will lik ely involve alum inum -sive intensubby Au to mo tive New ( A s utom otive News, 2 0 0 8 ) concluded structures ( e. g. , ax le assem blies, engine com nt,partm etc. ) e, that there m ay be a reduction in traction, because of lowand such com ponents are also now starting to penetr ate the rolling- resistance tires, that increases stopping idstance. new- vehicle population. The study is not rigorously controlled, and other inluCar glass ( windshield, side windows, rear window, ences m ay confound the results. The response by one tire m irrors, and sun roofs) is also heavy, and there re oppora m anufacturer, M ichelin ( Barrand and Bok ar, argues 2 0 0 8 ), tunities to reduce m ass by substituting polycarbona te. that low- rolling- resistance tires can be achievedwithout P olycarbonate can be coated to provide a durable in ish, and sacriicing perform ance factors by balancing the des ign and this has been applied to non- windshield glass panels where m anufacturing process variables. Tire m ak ers are ntinuing co scratching is less a concern. to research how to get optim al perform ance ( includi ng fuel econom y) without sacriicing other criteria such as safety or wear. Goodyear points out that perform ance trade offs Rolling Resistance between rolling resistance, traction, and tread wear can be Tire rolling resistance is one of m any forces that m ust be m ade based on m aterials and process adjustm ents, ich wh overcom e in order for a vehicle to m ove ( see discus sion in also affect cost ( Goodyear Tire & R ubber Com pany, 0 0 92 ) . Chapter 2 ) . W hen rolling, a tire is continuously form de ed by The increm ental cost for low- resistance tires m ot aybe n sigthe load ex erted on it ( from the vehicle m ass)repeated . The niicant, but the cost- beneit tradeoff with increase d stopping deform ation during rotation causes energy loss k now n as distance, wear, and possibly noise, vibration, and harshness rolling resistance. R olling resistance is affectedby tire issues are im portant for the consum er. design ( for ex am ple, m aterials, shape, andesign) tread dand R olling resistance can also be affected by brak es. L owinlation. U nderinlated tires increase rolling resis tance. The drag brak es reduce the sliding friction of disc brak e pads opportunity to im prove fuel econom y by reducingling rol on rotors when the brak es are not engaged because he t resistance is already used by OEM s to obtain better “EP A brak e pads are pulled away from the rotating rotor. M ost

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new vehicles have low- drag brak es.The im pact over conthis m ay increase com fort, it is not clear whether this will ventional brak es m ay be about a 1 percent reduction of fuel signiicantly im prove fuel econom y ( R ugh et al. 7 ,) 2. 0 0 consum ption. • Exhau st heat reco very R . ecent im provem ents in therm oR olling resistance is also affected by tire inlatio n, and electric m aterials for H V A C and ex haust energy veryreco so any technology that affects inlation levels can also afappear prom ising. R esearch is directed prim arily newatm afect fuel econom y. R educing tire inlation levels creases in terials with higher “therm oelectric igure of m erit” ( H erem ans rolling resistance, which in turn increases fuel consum pet al. , 2 0 0 8 ; H ussain et al. , 2 0 0 9 ) . lished This isbyaccom p tion. A tire pressure m onitoring system ( TP M be set S ) canincreasing the therm oelectric effect ( S eebeck coefi cient) to different pressure thresholds, and the average deviation and reducing the therm al conductivity. Good results have from the recom m ended inlation level would be 1e / 2 th been obtained with nanom aterial processing, but this at tim e threshold level. F or ex am ple, if the threshold et at is 1s 0 psi, these are costly. Im provem ents in potentially lowost bulk c the average deviation from the recom m ended level uldwo m aterials are needed for autom otive applications. M BW has be 5 psi. M ichelin believes that an accurate TP with M an S announced a planned introduction on production vehicles in appropriately set threshold could reduce fuel consum ption the 2 0 1 2 / 2 0 1 3 m2 Itodel presented year. a m odel of an ap3 and in the press.4 by up to 0 . 7 percent ( J . Barrand, personal com ation, m unic plication at the 2 0 0 6 D EER Conference M ay 1 2 , 2 0 0 9 ) . A D OE presentation gave m ore inform ation onhicle this ve 5 and presented a rather optim istic view of energy covery. re In the view of the com m ittee signiicant im provem s need ent Vehicle Accessories to be m ade in the perform ance of bulk m aterials in and the S om e autom ak ers are beginning to introduce electricprocessing of nanom aterials before therm oelectric eathredevices ( such as m otors and actuators) that can uce red the covery from the ex haust can be applied in m ass uction. prod m echanical load on the engine, reduce weight, and ptim o iz e The com m ittee think s that this will not happen hein1 t 0 - year perform ance, resulting in reduced fuel consum ption. Of horiz on considered here. course, the electrical power used by these devices m ust be furnished by the engine driving the alternator. Thus the m ost Transmission Technologies advantageous opportunities for converting m echanica l devices to electrical are devices that operate only interm ittently, Transm ission technologies can reduce fuel consum on pti such as power steering and air- conditioning com pres sor. The in two ways, irst by m oving engine operation to me efor beneits from electric and/ or electro- hydraulic powe r steericient regions of the engine m ap ( cf. F igure 2 Chap. 3 in ing and greater eficiency in air- conditioning ( A /are C) not ter 2 ) and second by continued reduction of the m hanical ec credited by current EP A fuel econom y tests ( since eithern losses within transm issions. Of these two, m oving ngine e operates during the test) , and so m anufacturers are reluctant operation to m ore eficient regions of the engine mp (ae. g. , to im plem ent them because of added costs. W new ith the higher torq ue ( or brak e m ean effective pressure;EPBM ) and EP A test procedures, som e of the beneits willlected be re in lower speeds) offers the largest potential gains. T he m ajor the “stick er, ” and im provem ents in these areas relatively are approaches to achieving this m ovem ent are by increa sing “low hanging fruit. ” the num ber of speeds in the transm ission ( whether anual, m autom atic, or continuously variable) and lowering nali drive • H eating , ventil ating , and air- co nditio ning . A ( H V ratio. AC) m ore eficient system starts with ( larger) heathangers ex c F ive- speed autom atic transm issions are already andard a st that transfer high heat m ore effectively and a ther m al ex - for m any vehicles; 6 - , 7 - , and 8 - speed autom ansm atic is- tr pansion valve that controls the evaporator tem perat ure. sions have been available on lux ury cars and are penetrating The com pressor uses the m ajority of the energythe of A / C into the non- lux ury m ark et. This new wave of autom tic a system , and variable displacem ent piston com pressor s are transm issions has been enabled by new power low con iguavailable and in use that signiicantly reduce fuel use over rations and im proved controls capability that are nabling e ix ed displacem ent com pressors. There are m any techother larger num bers of speeds to be achieved at a lowercost innologies, such as increased use of recirculated air, elevation crem ent over 4 - speed autom atics than would bease thefor c of evaporator tem perature, use of pulse- width m ated odul adding speeds to previous autom atic transm issionsigns. de blower speed controllers, and internal heat ex chang ers, that can further reduce fuel usage. 2 S ee http:/ / www. m otorward. com / 2 0 0 9 / 0 2 / -newnex detailston F urther reductions in fuel use can be achieved by edcreasgeneration- bm w- 5 - series/ . 3 S ee http:/ / www1 . eere. energy. gov/ vehiclesandfuels/ ing A / C load through the use of low- transm issivity glaz ing fs/ deer_ pd 2 0 0 6 / ( reducing both heat and ultraviolet penetration) , elective r session6 / 2 0 0 6 _ deer_ lagrandeur. pdf. 4 S ee http:/ / www. autobloggreen. com / 2 0 0 8 / 0 9 s/ 2k 5oglobe/ bm w- win “cool” paint, and cabin ventilation while park ed. uppliers S 2 0 0 8 - award- for- therm oelectric- generator/ . are investigating the use of directly cooling the seat either 5 S ee http:/ / www1 . eere. energy. gov/ vehiclesandfuels/ fs/ deer_ pd 2 0 0 6 / through ducting or by therm oelectric m aterials. hough A lt session6 / 2 0 0 6 _ deer_ fairbank s. pdf.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

NON- ENGINE TECH NOLOGIES

10 5

This cost im provem ent resulted from transm ission ar train ge m ark et, but recent trends suggest that their usage m ay not synthesis optim iz ation studies using com putational tools grow further due to higher than ex pected costs andlower than that uncovered gear trains req uiring fewer discreteelem ents ex pected internal eficiencies ( EP A , 2 0 0 8 ) . because som e of the elem ents ( e. g. , planetarytrains) gear The issues discussed above generally apply to both S I and are utiliz ed for m ultiple speeds. H owever, increasi ng the CI engines. H owever, the effects of m oving engine perato num ber of speeds always adds som e com ponents and eir th ing points to lower- speed and higher- torq ue regions of the associated cost. A long with higher num bers of trans m ission engine m ap are m ore beneicial for S I engines than or CIf speeds, which allow operating engines in m ore efici ent parts engines because intak e throttling losses are reduced for S I of their fuel consum ption m ap, transm ission interna l losses engines, whereas CI engines are not throttled. Nonetheless, are also being reduced, thus further im proving powe r train for both CI and S I engines, fuel consum ption is uced red eficiencies. by m oving to higher- torq ue and lower- speed regions of the In addition to planetary- based autom atic transm ons, issi engine m aps because the relative effect of engineriction f advanced versions of m anual transm issions are also e- b losses is reduced. ing introduced that can be m ore eficient than autom atics A nother im portant transm ission issue difference ween bet since torq ue converters are replaced by com puter-ntrolled co S I and CI engines is their peak torq ue. A s noted Chapter in 5 , clutches, which slip less than torq ue converters. hese T new CI engines produce higher m ax im um torq ues than I en-do S clutches not only are used to launch the vehicle from a stop gines. M ax im um torq ue capacity is one of the m m portant ost i but also enable rapid autom ated shifting of the m ual angears criteria for durable transm ission design, and so CI engines since one clutch can start engagem ent before the ot her clutch generally are m ated with different, higher- torq apacity ue- c has com pletely released. This class of m anuals is called dual- transm issions than S I engines even in the sam ecle vehi platclutch autom ated m anual transm issions ( D6 WCTs) ith. this form . S om etim es, a given transm ission used ngines for S I e concept, new- design m anual transm issions are arrang ed with can be upgraded to higher torq ue capacity by m ore x etensive two parallel gear trains, one for odd- num bered spee ds and and m ore ex pensive heat treating of the gears andlutch c the other for even- num bered speeds: for a 6 - speed CT,Done upgrading, but freq uently, different transm issions origi nally gear train would contain the irst, third, and ifthspeed gears designed for higher m ax im um torq ue capacity m usedust be while the other gear train would include the second, fourth, with CI engines, thus increasing cost, weight, andto som e and six th speed gears. D CTs are then coupled to the engine ex tent internal losses. through two clutches integrated into the transm issi on, one A nother transm ission- related technology that is liapp link ing the odd- speed gear train to the engine and the other cable to both S I and CI engines is called idle- stop . This techclutch link ing the even- speed gear train to the eng ine. F inally, nology is useful prim arily for operation in cities and involves the clutches are actuated with electro- hydraulic system s caliturning off the engine at idle. Beneits from idletops involve brated to provide sm ooth launch and rapid and sm hoot shiftelim inating m ost of the idle fuel consum ptiongdurin the idleing, m ak ing them autom atic in their interface e driver. to th In stop period. S ince idle fuel consum ption is relativ ely large m ost of the current im plem entations of these clutch es, they for S I engines due to throttling losses and the useof ignition are im m ersed in transm ission oil, thus providing e cooling th retard for sm ooth operation when accessories turn on and off, necessary for acceptable durability. D ry- clutch sions ver are F C reductions on the F ederal Test P rocedure ( F riving TP ) d now also being developed for vehicles with lower torq ue cycle range from 3 to 5 percent. The real- world n for gai req uirem ents, m ak ing oil cooling unnecessary.lutch D ry- c congested city driving ( e. g. , New Y ork City) be could as high D CT designs are ex pected to be less costly to produ ce and as 1 0 percent since engines would be idled m uch emthan or lighter than their wet- clutch counterparts. In addi tion, dryon the F TP test cycle. A ll idle fuel consum ption sses are lo clutch D CTs will be m ore eficient through elim on inati of not elim inated since som e accessories m ay need perated to o the hydraulic pum p work to cool the wet clutches. while the engine is stopped ( e. g. , A / C in hot clim tes) , awhich Both autom atic and D CT transm issions feature arete disc not only consum es som e fuel but also increases com onentp num ber of gear ratios that determ ines the ratio engine of cost by the necessity of replacing belt- driven accessories speed to vehicle speed. In contrast, a continuouslyvariable with electrically driven ones. F or the CI diesel ve hicle, idletransm ission ( CV T) offers a theoretically ininite hoicec of stop beneits are sm aller than those attained withdlei stop for ratios between ix ed lim its, which allows engine rating ope S I gasoline vehicles because diesel engines have mchulower conditions to be optim iz ed for m inim iz ing fuel um cons ption. idle F C than their gasoline counterparts. The estim ated gain CV T technology has tended to be used in lower- horse power on the U . S . cycle for CI vehicles is about 1 percen t, although vehicles because of m ax im um - torq ue lim itations the withthe real- world gain for congested city driving ( e.. g, in New m ost com m on m etal- belt design. A few OEM ss offerYCV orkT City) could be m uch higher. that utiliz e other drive schem es allowing usage wit h larger Other studies of vehicle fuel consum ption ( e. g. , C,NR engines. CV Ts have achieved som e penetration into e th 2 0 0 2 ) have generally considered potential gains m fro transm ission technologies in a separate category from gine en eficiency technologies. In the present study, poten t ial gains 6 S ee http:/ / www. dctfacts. com / hm S tory1 b. asp.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

10 6

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

from transm ission technologies are considered toget her with directly proportional reduction of fuel consum ption because those for engines. This choice was m ade for the following of ( 1 ) the accessory load and ( 2 ) the possibility hat the t reasons. F or S I engines, the m ajor opportunity reducing for power train m ay then operate at worse eficiency poi nts. To fuel consum ption ( as is discussed ex tensively in Chapter 4 ) istak e care of the power train eficiency it is necessary, at the reducing pum ping losses. M any of the technologysures m ea sam e tim e, to downsiz e the engine and/ or change nsmtraisdiscussed in Chapter 4 reduce pum ping losses in one way or sion shift points, because with a lighter load, theeficiency another. A s noted above, the m ajor im pact of ission transm of the power train is reduced, especially with S Ingines e that technologies toward reducing fuel consum ption is tom ove will then operate with m ore throttling. U nfortunate ly, m any the operation of the engine toward higher torq ue (roBM EP ) studies on the im pact of reducing mFand Fa do not change and lower speeds at which pum ping losses will be re duced. the engine operating points. F or ex am ple, Barrand andarBok A s a result, there are signiicant interactions betw een engine ( 2 0 0 8 ) do an ex cellent job of investigatingect theofeff rolltechnologies that reduce pum ping losses ( e. g. , evalv event ing coeficient by changing tires without changing the power m odulation) and transm ission changes that also mengine ove train. Only an OEM designing a vehicle with low-lingrol operation to lower speeds and loads, such as increasing the resistance tires, for ex am ple, can fully tak e advan tage of 7 A num ber of ratios and the associated ratio spread. good rolling- resistance changes by reoptim iz ing the powe r train. ex am ple of these interactive effects is cylinderactivation, de Theoretically reducing any one of the three com pone nts as discussed in Chapter 4 . W hen cylinder deactivati on is by, say, 1 0 percent should reduce fuel consum ption by used, the beneit of m oving the engine operating poi nt to roughly 3 . 3 percent since, as stated above, each m coponent lower speeds and higher torq ues and higher BM EPreduced is accounts for roughly one- third of the total tractive energy. In com pared to engines not using cylinder deactivation , because fact the siz e of the engine is determ ined by accele ration perthe work ing cylinders are already running at higherBM EP , form ance req uirem ents, as well as the tractivegy. ener Therethereby reducing pum ping losses. Thus the fuel cons um ption fore all that can be said for certain is that reduction of all three reductions possible from increasing the num berransm of t iscom ponents by an am ount ( X say, percent) would result in a sion ratios from 4 to 6 , for ex am ple, would rbeforlowe reduction in fuel consum ption by roughly the sam me aount engines using cylinder deactivation than for those not using (X percent) , assum ing the power train were reoptimd. iz e cylinder deactivation. This dem onstrates how transm issionderived fuel reductions of fuel consum ption cannot readily be Aerodynamics separated from engine- technology- derived fuel consu m ption reductions. This choice is relected in the technology paths A s discussed above, vehicles with higher dCvalues discussed in Chapter 9 . ( over . 3 0 ) m ay be able to haved the reduced C by 5 percent or so ( up to 1 0 percent) at low cost. The associate d im pact on fuel consum ption and fuel econom y could be 1 2 to FUEL CONSUMPTION BENEFITS OF NON-ENGINE percent, and this assum es that the engine operating regim e TECHNOLOGIES is not m odiied. If lower acceleration can be tolera ted and The tractive force that is needed to propel a vehithe engine operates at the sam e eficiency, the imovem pr ent cle can be written sim ply as the sum of three force s: with a 1 0 percent reduction of aerodynam ic dragldcou be as high as 3 percent ( 1 0 percent × 0 . 3 ) . A rgonne calculations FTR = m F + rF+ aF for the im provem ent in fuel consum ption show that ithout w engine m odiications a 1 0 percent reduction in aerod ynam ic where Fm accelerates the m ass, r Fovercom es rolling resisdrag would result in about a 0 . 2 5 percent reduction in fuel tance, and Fa overcom es aerodynam ic drag. The integral consum ption for the urban cycle and a 2 . 1 5 percent change of this force over a given driving cycle gives the am ount of for the highway cycle. energy req uired at the wheels. U sing typical values in Eq uation 2 . 1 one can calculate that for the EP A com d cycle bine Car Body Design and Interiors about one- third of the tractive energy goes into each of these three com ponents ( see Table 2 . 7 ) . H owever, 2as . Table 7 It is well established that a reduction in vehicle m ass reshows for the urban cycle, Fm is around 6 0 percent of the duces fuel consum ption. The speciic relationship tween be total and for the highway cycle, Fa is about half. Before givm ass reduction and fuel consum ption, however, m is coplex ing estim ates of the beneits of fuel- saving technol ogies, it and depends on m any factors: is necessary to m ak e two im portant points. M erely reducing tractive energy does not translate into a • A m ount of m ass reduction, • D riving cycle, 7 R atio spread is deined as the ratio of irst gear di vided by the ratio • Type of engine, and of the top gear. A s an ex am ple, for a typicaled 6 autom - spe atic transm is• S econdary beneits, such as whether or not othervesion, the low- gear ratio would be 4 . 5 8 :1 while of that the six th gear would hicle system s are redesigned to m atch the new vehic le be 0 . 7 5 :1 . The ratio spread would then be 4 . ,5 which 8 / 0 eq . 7 uals 5 6 .1 .

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

10 7

NON- ENGINE TECH NOLOGIES

m ass, as with, for ex am ple, engine downsiz ing, ned retu fuel econom y im pact; Table 7 . 3 shows the range m pact of i transm ission, and reduced com ponents for crash m an-on fuel econom y for all types. agem ent, brak ing, fuel storage, and so on. Table 7 . 3 shows the results of the R icardo, Inc. im ,ulation s calculating the potential im pact on fuel consum ptio n from A m idsiz e car body structure with closure panels o ( n reduction of m ass. The range shown in the resultss due i to trim or glass) can weigh approx im ately 8 00 pounds about ( sum m ariz ing a com posite of sim ulation runserent for diff 25 percent of the vehicle’s total curb weight) . Suld hothe vehicle m odels and power trains. This discrepancyrange ( m ass reduction be signiicant, a secondary beneit nca of fuel econom y im pact) in fuel econom y im provem inent accrue from reducing the siz e of the needed power rain, t creases for different vehicle types as the reduction in m ass brak ing system s, and crash m anagem ent structures. These increases from 5 to 2 0 percent. H owever, ifine theiseng secondary beneits are dificult to estim ate but canpotenresiz ed to m atch each level of m ass reduction (aintain to m tially approach an additional 3 0 percent reduction in m ass, original vehicle perform ance) , the range of fuelonom ec y and these secondary beneits can help offset the cost of the im provem ent across the vehicle classes is fairlyall. sm This initial effort ( IBIS A ssociates, 2 0 0 8 ) . observation points to the im portance of m atchinggine en A basic estim ate of the relationship between fuel cone perform ance to vehicle m ass. F or sm all ( under cent) 5 per om y and m ass is provided by the D epartm ent ofy Energchanges in m ass, resiz ing the engine m ay not be tiied, jus but ( Carpenter, 2 0 0 8 ) and also by the L aboratory nergy forand E as the reduction in m ass increases ( greater than 1percent) 0 , Environm ent at the M assachusetts Institute of Techn ology it becom es m ore im portant for certain vehicles esiz to re the ( Cheah et al. , 2 0 0 7 ) . A rule of thum b ercent is a 6 im to 8- p engine and seek secondary m ass reduction opportunit ies. provem ent in fuel econom y ( or, eq uivalently, ction a redu of P hysical vehicle testing has conirm ed the reduction s 5 . 7 to 7 . 4 percent in fuel consum ption) for0 every percent 1 in fuel consum ption associated with reductions in ehicle v drop in weight when secondary beneits are included that m ass. F or an internal com bustion engine, the of effect m ass indirectly accrued from having lower m ass. reduction is greater with a city driving cycle versus a highIn a study conducted by R icardo, Inc. ( 2 0 0 7pon) , and s way cycle because of the freq uent acceleration/ dece leration sored by the A lum inum A ssociation, this relationshi p was of m ass. F or ex am ple, vehicles ( com binationact, of com p sim ulated for several vehicles loaded with from o25 t pasm idsiz e, and S U V classes) powered by internal stion com bu sengers. The gasoline- powered vehicles sim ulatede ar listed engines can reduce fuel consum ption approx im ately s fola in Table 7 . 2 . lows ( P agerit et al. , 2 0 0 6 ) : 0 . 1 gallon es perdriven 1 0 0 m il Two scenarios for these vehicles were sim ulated. Th e can be saved with, approx im ately, irst scenario evaluated the im pact on fuel econom when y everything about the vehicle rem ained unchanged exeptc • 1 9 0 pounds m ass reduction—city cycle, and for a reduction in vehicle m ass. The second scenari o re• 2 8 5 pounds m ass reduction—highway cycle. siz ed the engine to relect com parable vehicle perfo rm ance ( the beneits of other reductions in m ass such assm a aller A s discussed in P agerit et al. ( 2 0 0 6 ) and upported further by s gas tank , sm aller brak es, etc. were not included) In this . the R icardo, Inc. , study, the im provem ent gained om reducfr scenario, the engine req uired less power because ofthe tion of m ass ( ex pressed as fuel consum ption andmnot iles reduction in m ass, and therefore, fuel econom yfurther was per gallon) is the sam e regardless of the weight the of vehicle. im proved. The vehicle type was not a m ajor differen tiator of U nlik e changes in rolling resistance and aerodynam ics, re-

TA BL E 7 . 2 V ehicle M ass A ssum ptions for . (R2 icardo, 0 0 7 Inc ) S tudy to A ssess Effects of M assonRF eduction uel Econom y Type of V ehicle S m all car M idsiz e car S m all S U V L arge S U V

Initial W eight ( lb) 2 ,8 7 5 3 ,6 2 5 4 ,2 5 0 5 ,2 5 0

L oad W eight ( lb)%

R eduction 5 ( lb)

3 0 0 4 5 0 5 5 0 7 5 0

1 0 %

3 ,0 3 1 3 ,8 9 4 4 ,5 8 8 5 ,7 3 8

R eduction ( lb) 2 ,8 8 8 3 ,7 1 3 4 ,7 3 5 5 ,4 7 5

2 0 % )

R eduction ( lb 2 ,6 0 0 3 ,3 5 0 3 ,9 5 0 4 ,9 5 0

NOTE: The 5 percent, 1 0 percent, and 2 0 percent s reduction m as applies to the initial vehicle weight and not the load.

TA BL E 7 . 3

Im pact on F uel Consum ption D on ue to of R M educti ass in S tudy by R icardo, Inc. ( 2 0 0 7 )

V ehicle M ass R eduction from M ass reduction only M ass reduction and resiz ed engine

Baseline V ehicle

5R %eduction M ass 1 -2 % 3 - 3 .5 %

1 0 %

M ass R eduction

3 -4 % 6 -7 %

2 0 %

M ass R eduction

6 -8 % 1 1 -1 3 %

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

10 8

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Vehicle Accessories

ducing m ass not only reduces the am ount of tractive energy needed but also perm its a reduction in power train( engine downsiz ed or transm ission shift changes) withoutversely ad affecting perform ance ( acceleration) . A 1 0 percent reduction in m ass and power for the reference vehicle shouldreduce fuel consum ption by about 5 . 7 to 7 . 4 percent to ( or 7 6 percent) . In a conventional vehicle, the energy use d to accelerate the m ass is m ostly dissipated in the brak s, whereas e in a hybrid, a signiicant fraction of this brak ingenergy is recovered, sent back to the battery, and reused. Thus, m ass reduction in hybrid vehicles is less im portant than in conventional vehicles. The com plex ity of m ass reduction ncreases i when a conventional vehicle is com pared with eithera hybrid ( which incurs additional battery m ass) or a engine CI ( which has greater power train m ass) . W hile reducin g m ass will always provide a fuel econom y beneit, changing technology pathways ( between S I, CI, or hybrid designs) has to recogniz e the im pact that the new technology has on m ass. Rolling Resistance A report on tires and fuel econom y ( NR C, 2 0m 0 ates 6 ) that a 1 0 percent reduction in rolling resistanceill w reduce fuel consum ption by 1 to 2 percent. This reduction, however, is without changes in the power train. If the power train could be adjusted to give the sam e perform ance, then beneit the of a 1 0 percent reduction would be on the order of as m uch as 3 percent. U nderinlated tires that are 2 0 percen t below recom m ended inlation pressure ( say, 3 5 psi)e rolling increas resistance by 1 0 percent, and thus increase fuelnsum co ption by 1 to 2 percent ( Goodyear Tire & R ubber Com2 0pany, 0 9 A gain as discussed above under “A erodynam ics,re” if a duction in rolling resistance is com bined with a re duction in aerodynam ics and m ass, the power train can be signi icantly m odiied to im prove eficiency. A s indicated in er Chapt 2 , rolling resistance accounts for about a third of the energy going to the wheels for the city as well as the highway cycles. R educing m ass, aerodynam ics, and rolling resistance by 1 0 percent reduces fuel consum ption by about 1 0 percen t with power train resiz ing and other drive train adjustmntse ( e. g. , changes in transm ission shift points, ax le ratios) A .s noted earlier, vehicle m ass reduction for a hybrid is not as effective since som e of the energy going to the brak es is overed. rec

TA BL E 7 . 4 V ehicle A ccessory

Transmission Technologies F uel consum ption reductions generally increase with additional transm ission speed ratios, although inte raction effects between engine technologies that reduce pumping losses and increase the num ber of transm ission spee ds are im portant, as noted earlier. H owever, since the ts cos also increase and the m arginal gain for each additionalspeed gets sm aller, there are dim inishing returns. Table 7 . 5 lists the transm ission technologies and estim ated reducti ons in fuel consum ption. The basis of this table is baseli ne engines

P otential R eduction of F uel Consum ith theption U se w of V ehicle A ccessories R eduction in F uel Consum ption ( % )

V ariable- strok e H V A C com pressor L ow- transm issivity glaz ing, cool paint, ~ 1 park ed- vehicle ventilation Electrohydraulic power steering 4 Electric power steering

The opportunity m ay ex ist to decrease fuel consumionpt ( in gallons per 1 0 0 m iles driven) by about ercent 3 to 4with p a variable- strok e H V A C com pressor and better l ofcontro the am ount of cooling and heating used to reduce um h idity ( Table 7 . 4 ) . Estim ates for further reductions canthat be achieved by decreasing air conditioner load through the use of low- transm issivity glaz ing, relective “cool”nt,paiand cabin ventilation while park ed have not been determined. A ccording to a D eutsche Bank report, electro- hydrau lic power steering ( EH P S ) would reduce fuel consumbyption 4 percent with an increm ental cost of $ 7 0 , while tricelec power steering could im prove 5 percent with an increm l enta cost of $ 1 2 0 , but there is little inform ation on how s estim thi ate was obtained ( D eutsche Bank , 2 0 0 8 ) . A TR essat, W study ( G 2 0 0 showed 7 ) that while a conventional hydraulic power steering system consum ed 0 . 3 5 L / 1 0 0 k m W , the best T electro- hydraulic steering system consum ed 0 .d0 an 7 an electric power steering system 0 . 0 2 . These igures re relative a to a sm all vehicle with a 1 . 6 - L engine. Inyitsofstud CO2reducing technologies for the EP A ( EP A , 2 0ardo, 0 8 ) , R ic esti Inc. , found that electric power steering ( EP S ) ced redu com bined fuel consum ption by about 3 percent based on F S S calculations. F rom this and the estim ates provided in recent regulatory activities by NH TS A and EP A , the ee com m itt estim ated that EP S reduces com bines fuel consum n by ptio about 1 to 3 percent on the EP A 5 5 / 4 5 com e, which bined cycl is the basis for the CA F E standard. H owever, m the co m ittee recogniz es that the reduction of fuel consum ptionould c be as high as 5 percent under in- use driving condition s. ).

1 -5

3 -4

Com m ents Im heating, proved cooling, and hum idity control L ower heat buildup in vehicle decreases air- condi tioning load Com bined electric ndahydraulic power for m idsiz e to larger vehicles educes r continuous load on engine Electric power steering or fsm aller vehicles reduces continuous load on engi ne— sm aller beneits ( 1 - 3 % ) estim ated for the F TP

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

10 9

NON- ENGINE TECH NOLOGIES

without signiicant valve event m odulation technolog ies or cylinder deactivation.

A utom obile m anufacturers differ signiicantly ir inapthe proach to introducing new products. M anufacturersased b in A sia, for ex am ple, are k nown for having shorter ductpro life cycles but often im plem enting lower levels of engin eering TIMING CONSIDERATIONS FOR INTRODUCING NEW redesign at changeover. M anufacturers based in Euro pe and TECHNOLOGIES North A m erican have traditionally had longer produc t cycles The tim ing for introducing new fuel consum ptionhnoltec with a greater am ount of engineering applied at cha ngeover. ogies can signiicantly inluence cost and risk . Them aturity There are always ex ceptions to these generalities veen within of a technology affects its cost and reliability. Autom obile a m anufacturer, depending on the vehicle m odel. stratThe com panies have sophisticated p ro du ct and p ro cess val idatio egy n to im plem ent engineering changes on a regional vehicle p ro cedu res that m ust be adhered to before products can be ( e. g. , North A m erica only) versus a global platform can scaled up for m ass production, or they ex pose them elvessto greatly im pact tim ing and cost. Entire tex tbook ve sbeen ha large warranty or product liability concerns. M any vehicle written around product tim ing for m anufacturers,d so an a changes are tim ed for im plem entation around the duct pro discussion here can at best only introduce the inherent issues developm ent process to m inim iz e cost and q uality ncerns. co that affect cost and tim ing for any m anufacturer. L ower- volum e and higher- end vehicles often havetechnew Generally, 2 to 3 years is considered the q uicktim est e nologies applied irst for several reasons. The lower volum es fram e for bringing a new vehicle to m ark et. Aicant signi m itigate the ex posure to risk , and the higher- ehicles end v am ount of carryover technology and engineering from other can bear the higher initial early cost of a new technology. m odels ( or previous vehicle m odels) is usuallyired req tou D uring this period, com petition brings the technolo gy cost launch a new vehicle this q uick ly. In som e cases, o m s uch down while the supply chain develops for higher volum es of the vehicle is replicated that the new vehicle is considin the future. ered a “freshened” or “re- sk inned” m odel. The ty abili to A n im portant consideration for introducing new technolo- signiicantly inluence vehicle perform ance ( e. g. rough , th gies that have broad im pact concerns the product de veloplight- weighting, changing power trains, etc. ) isnim m i al bem ent process of new vehicles. A ggressive use ofhtweight lig cause so m uch of the vehicle is unchanged. M orestantial sub m aterials to obtain secondary beneits; power train m odichanges to the vehicle occur over longer periods of tim e. ications; and body shape m odiications ( to im prove ero- a Newly styled, engineered, and redesigned vehicles acn tak e dynam ics) , for ex am ple, m ay have to be tim uture ed with f from 4 to 8 years, each with an increasing am fount newo product developm ent phases. A lthough m aterialitution subst content. for com ponents can occur throughout the life cycle of a car A utom obile producers generally have product develop in m any cases, the m ass saved in this way is relati vely m inor. m ent program s ( P D P s) spanning at least 1 5P years. s P D Considering how to reduce m ass to achieve greaternergy e are ex trem ely irm for 3 to 5 years due to the forneed longsavings req uires a broad system s evaluation and ngineerree lead- tim e item s such as tooling or supplier develop m ent ing of the vehicle. Once a vehicle has been validated and req uirem ents, and the need for ex tensive testingmofajor tooled for a speciic design and production has begun, new item s such as those req uired for fuel econom y, sions, em is developm ent costs are planned for future m odel chan ges. and safety regulations, and conirm ation of reliabil ity and M ost signiicant m odiications have to occur around arious v durability. In general, m odel changeovers can be tegoca phases of the vehicle’s production life. riz ed into ive areas ( freshen, re- sk in, restyle, engineer, re

TA BL E 7 . 5 Transm ission Technologies and Estim eductions ated Rin F uel Consum ption Technology F ive- speed autom atic transm issions S ix - speed autom atic transm issions S even- speed autom atic transm issions Eight- speed autom atic transm issions D ual- clutch autom ated m anual transm issions ( 6 - speed) ( D CT) Continuously variable transm issions

F uel Consum ption a( % ) R eduction 2 -3 3 -5 5 -7 6 -8 6 -9

1 -7

Com m ents Technology also im can prove vehicle perform ance

Original autom atic transm issions with convention al m anual transm issions supplem ented with electro- hydraulic clutch and shif t actuators have been replaced with D CTs S om eelated issuestor differences in feel and engine noise; im rovem p ents depend on engine siz e

NOTE: V alues based on EEA ( 2 0 0 7 ) with adjustm o relect ents range t of values lik ely to occur. aIm provem ents are over a 2 0 0 7 naturally aspirated - engine S vehicle I with 4 - speed autom atic transm of ission sim ilar perform ance characteristics.

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over a 1 5 - year life cycle can be substanti al, and and redesign; see Au to mo tive New J uly s, 1 4, 2008 , p. 28 )nologies . the perform ance im provem ent for fuel consum ption n be ca These ive categories and their potential for effecting fuel consum ption im provem ents are described in Table . It7 . 6 substantial with a new power train. The estim ates in Table 7 . 6 are based on business usual. as is not accurate to say that every vehicle progresses through The “freq uency” is the tim e from concept through oto-pr every one of these phases. It is possible to sk ip rea sk in and typing, production vehicle design, tooling release,veriicajum p to a restyle, for ex am ple. A lso, not every icle will veh tion testing on preproduction vehicles, and start of full- scale be redesigned in 6 to 8 years because m any factors affect especif this tim ing ( m ark et dem and, inances, etc. )ential . The pot production. S horter tim e fram es are possible, ially st for im pacting fuel consum ption is only a rough appr ox im a- m ore vehicle content is carried over between P D o Preduce engineering, testing, etc. , but this lim its theree degof m odel tion, and none of these estim ates consider the incl usion of , sm g. aller hybrid or alternative power trains. The estim ates for reducing changeover. U rgency to introduce new vehicles ( e. and m ore fuel eficient vehicles) can accelerate the nom inal fuel consum ption shown in Table 7 . 6 are not additive ( from duration of each P D P phase, but the investm ent willcost grow. previous changeover phases) . F uel consum ption estim ates M odest im provem ents in fuel consum ption caneved be achi also assum e com parable vehicles of the sam e siz d pere an early in the P D P cycle ( e. g. , freshen and retages) sk inby s form ance ( including crash worthiness, electronicntent, co introducing m ore aerodynam ic designs and low- rollin gand other factors that are often adjusted with new vehicles) . resistance tires. A greater im pact on reducing fuel consum pThe engine developm ent process often follows a path tion can com e from changes in engine, transm ission, and m ass separate from those of other parts of the vehicle.Engines reduction later in the P D P when the vehicle isesigned red or have longer product lives, req uire greater capital investm ent, reengineered. R estyled vehicles allow for m aterial substituand are not as critical to the consum er in differen tiating one vehicle from another as are other aspects of the ca r. A lso, tion on a part- by- part basis, but without changingentire subassem bly structures. Often, the substitution m ht be ig for a consum er- driven changes for styling change faster han t the higher- strength m etal with a thinner gage in place of the curneed to introduce new power train technologies. Thepower ay b train developm ent process evolves over closer to 1a 5 - year rent m aterial. Tooling and assem bly processes me altered som ewhat to accom m odate the new m aterial. A neered reengi cycle, although reinem ents and new technologies wil l be vehicle allows for changing the design of m ajor sub assem blies im plem ented throughout this period. A lso, because f the o ( engine com partm ent, closure panels, body sides, c. ) , etthus com plex ity, costs, and resources req uired to launch a new allowing for entirely new approaches to reducing m ss. a R epower train, it is unusual to launch a new engine- elated r engineered vehicles norm ally req uire crashworthines s testing transm ission sim ultaneously. The developm ent oftechnew

TA BL E 7 . 6 V ehicle P roduct D evelopm ent Ppower rocess train) ( nonand Tim ing Im plications to Effect FEconom uel y Changes Type of M odel F req uency Change ( Y ears) F reshen

R e- sk in

2 -3

3 -5

R e- style

4 -8

R e- engineer

4 -8

R edesign A

6 -8

D escription

F uel Consum ption Opportunities to Im pact F uel R eduction Consum ption

S heet m etal untouched, m ay include new L ittle to none grille, fascia, headlights, taillights, etc. (≤3 % )

Investm ent Cost

M inor im pact on m ass; possible L im pact with aerodynam ics and tires M inor changes to sheet m etal Le ittle to non S am e as above and vehicle M (≤5 % ) accessories Ex tensive changes to ex terior and or interi M inim al S om e im pact on m ass ( m ostly H (5 -8 % ) interior com ponents) ; possible im pact with aerodynam ics, tires, and vehicle accessories Ex tensive m ak eover of vehicle’s orm platf , M oderate M ass reduction opportunity with V chassis, and com ponents to reduce noise, (7 -1 4 % ) part- by- part m aterial substitution vibration, and harshness and im prove ( e. g. , alum inum or high- strength q ualities such as ride, handling, brak ing, steel) ; possible im pact with and steering ( this degree of change or the aerodynam ics, tires, and vehicle nex t m ay req uire recertiication and crash accessories testing) , body restyling often concurrent with this phase New platform , new interior and r ex terioS igniicant Entire vehicle structure—opportunity V styling; engine and transm ission carried (1 3 -1 8 % ) to introduce lightweight m aterials over; som e structural subsystem s possibly throughout entire vehicle; im pact reengineered from aerodynam ics, tires, and vehicle accessories

ow

odest igh

ery high

ery high

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and incur signiicant additional costs because of the reengineered designs. The redesigned vehicles start with a “clean sheet” affording the beneits of a reengineered vehicle, along with m ore optim al m atching of the power traine to lighterth weight structure. In general, a redesign results ina new vehicle platform that in m any cases replaces ex isting vehic les.

as carbon iber will need signiicant cost reduction and supply chain developm ent over the nex t 1 5 years. e com Th m ittee does not ex pect to see signiicant inroads in this tim e fram e by this technology ex cept in low- volum eializ ( spec ed applications) , high- perform ance vehicles. Otherym pol er/ reinforced com posites, etc. will continue to m nroads ak e i in the vehicle interior where steel or alum inum is used currently for strength. F or ex am ple, all- polym er/ reinforced om posite c Aerodynamics instrum ent panels ( without rear steel reinforcem s)entare R eductions of drag coeficient Cd by 5 percent or (soup lik ely to m ak e it to production soon. to 1 0 percent) have been tak ing place and will inue. cont A A s production processes continue to be developed, 5 percent reduction in aerodynam ics can be achieved with broader application of both m agnesium and titanium can m inim al cost through vehicle design, and largeructions red be ex pected, such as for m agnesium engine block at s th can be achieved by sealing the undercarriage and installing weigh approx im ately 3 0 pounds less than alum inum es on covers/ shields ( e. g. , in the wheel well areas and nderbody) u . ( see Table 7 . 7 ) . M agnesium will lik ely m ak for e inroads Elim ination of outside rear view m irrors will req uire changes com ponent parts such as suspension arm s and interio r dash in safety regulations and im provem ent in vision tem sys s. panels and seating brack ets. Titanium will continue to ind S ince these changes can be costly, they are unliky elto be application in suspension springs, valve springs, valves, im plem ented soon ex cept on high- end vehicles.e longer In th connecting rods, and ex haust system s, resulting3 in5 to 4 0 term ( about 1 0 years) , 5 to 1 0 percent reductions n aero- i percent savings in m ass over steel com ponents. dynam ic drag are plausible, but this m ay com esom with e com prom ise in vehicle functionality. Rolling Resistance L ow- rolling- resistance tires are already used by OE M s. The com m ittee does not ex pect signiicant additional im R eductions in weight have been tak ing place and wil l provem ents without sacriicing perform ance. S ince placere continue in the near term with reductions from 1ercent 0 p m ent tires are on m ost vehicles on the road today, a cam paign ( with m ostly conventional and high- strength steels) to 2 5 to educate purchasers of replacem ent tires of theossibility p percent ( with high- strength steel structures, alum numi cloof fuel savings is a good way to reduce fuel consumption. sure panels, and body/ interior com ponents m ade from variM ore vehicles today are being offered with low- tire - pressure ous lightweight m aterials) . Table 7 . 7 provides an overview ofm onitors to warn the driver of underinlated tiresorf safety the tim elines for the introduction of new m aterials for variand fuel econom y. ous vehicle com ponents. Today’s new vehicles alread y are com posed of upward of 4 0 to 5 0 percent high-hstrengt steel Vehicle Accessories ( over 4 8 0 M P a yield strength) , but higher-steels strength ( advanced high- strength steels) are being developed (puto 1 , 0 0 0 V ariable strok e com pressors and reduction of subcoo ling M P a) that could replace even the current high- gth stren steel. are being developed and should appear in vehicles in the nex t V arious vehicle com ponents for which isolated mialater sub3 to 5 years. Because the current duty cycle m easur ing fuel stitution can tak e place will also be the norm . Fex oram ple, consum ption does not recogniz e H V A C systemis no s, there F ord recently indicated that alum inum calipersaced replsteel m otivation to introduce these system s because they incur ones, thus saving 7 . 5 pounds per vehicle. A lso, m alu inum additional costs. H owever, the proposed new EP At procetes wheels replaced steel wheels, resulting in 2 2 pound s saved dure m ay cause new interest in introducing this tec hnology. per vehicle. M ore aggressive application of alum minu to car doors can also save another 2 0 pounds per door, but at a COSTS OF NON-ENGINE TECHNOLOGIES higher cost. S ubstitution of m aterial in other com onents p can also be ex pected, including the wiring harness. Sstituting ub Aerodynamics copper- clad alum inum wiring for all copper wiring an save c 1 0 or m ore pounds per vehicle, but usually at her a higcost. A 5 percent reduction in aerodynam ics can be achiev ed M ore aggressive reduction of m ass is feasible at gher hi with m inim al cost through vehicle design. S lightly m ore cost if aggressive targets of greater than 2 5 perce nt are set. aggressive reductions can be achieved by sealing the underR eduction of m ass at the 5 0 percent level cantained be at in carriage and installing covers/ shields ( e. g. , ine th wheel well the body with a m ostly alum inum structure ( probably using areas and underbody) costing in the tens of dollars. A 1 0 a space fram e design) , but this approach will bestcoprohibipercent reduction in aerodynam ics m ay be aggressive , calltive under m ost conditions for high- volum e vehicles . ing for wind delectors ( spoilers) and possibly elim ination of The use of com posite structures involving m aterials such rear view m irrors, which would cost a few hundredollars. d Car Body Design and Interiors

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TA BL E 7 . 7 Tim ing

Estim ated Tim eline for Introduction w Mof aterials Ne by Type of Com ponent

H igh- S trength S teel

A lum inum

M agnesium

Current or near Body rails, door sills, B- pillar, H ood, deck lid, engine block Instrum ent panel, term ( 3 - 5 side roof rails, underbody, and cylinder lining, front seat com ponents years) front suspension subfram e, suspension subfram e, bum per Brack ets bum per beam s, crossbeam s, rear suspension Crash structures m em bers, brack ets and k nuck les, steering hanger Intak e m anifold reinforcem ents, ex terior beam , power train com ponents body panels, body side ring, ( castings) , condenser/ radiator longitudinal rails, wheels wiring harness F uture S am e as above, only with D oors, ex terior body panels D oor, inner ( 5 - 1 0 years) higher- strength steels ( fender, roof) Engine block

L ong term New steels with greater ( > 1 0 years) form ability allowing application to m ore com plex part shapes and ex terior panels; less steel overall in the vehicle

Car Body Design and Interiors

Increased applications L ( depending on m aterial cost) ; subassem blies such as engine com partm ent, chassis, instrum ent panels; overall, m ore alum inum in the vehicle

im ited increase in applications; possibly transm ission parts

and P olym P lastics er—Com posites

Truck box Outer sk in panels ( doors, fenders, etc. ) Instrum ent panel Bum pers Trim Engine parts ( intak e m anifold, cover, etc. ) Body side ring R oof S ide pillar ( B or C) U nderbody S eat com ponents S ound dam pening Glass ( polycarbonate) New m aterials will be developed with higher strength, allowing them to be applied to m ore structural parts. M ix ed- m aterial bonding will be developed. Overall, m ore plastics/ polym ers will be in the vehicle.

m any incum bent steel parts or assem blies, and tructural the s com ponents that are am ong the heaviest parts offeri ng the The term “m aterial substitution” often m isrepresent s greatest opportunity will be targeted. P lastics, m co posites, the com plex ity and cost com parison when one m l ateria is and other m etals ( m agnesium and titanium ) sed willon be u substituted for another one. The cost to change m erials at in a som ewhat lim ited basis because of cost. the vehicle, from an incum bent m aterial to ar-lighte weight In recent years, reductions in m ass have been reali z ed m aterial, is a function of capital and variable cos ts: in the body, interior, and power train by introducing new m aterials such as high- strength ( and advanced high- strength) F ix ed Costs ( up- front investm ent costs) steels, plastics ( not including carbon iber) , andlum a inum . • D esign and engineering M agnesium has also been used to reduce m ass, abut m touch • P rototype developm ent and testing lesser ex tent. In the near future ( 5 years) , the m co m ittee ex • Tooling: fabrication, dim ensional m easurem ent, pects continued m ass reduction following the sam attern; ep and assem bly through continued introduction of m ore and higher-trength s steels, alum inum , plastics/ polym ers, and tor aexlesse tent V ariable Costs ( a function of the volum e of product ion) other m aterials such as m agnesium . • P roduction and assem bly labor cost A lthough there are research and developm ent costs o t • P roduction eq uipm ent develop new high- strength steels and new m anufactur ing • M aterial processes for them , once developed they have m inim l net a • J oining ( welding, adhesive, sealing, riveting, etc. ) long- term increm ental cost over m ild steel. Tooling , fabrication, and joining costs tend to be higher for thesem aterials beA n added com plex ity results with m aterial substitut ion cause of the m aterial strength, which has to be add ed to the net because part design is m aterial dependent, and the redesigned cost difference. A lthough the cost per pound of high- stren gth part m ay provide ( and often does) different functio nality steel is higher than m ild steel, less of it is need ed. H ence, a than the original part. F or ex am ple, a m olded ic part plast 1 0 or 2 0 percent m aterial cost prem ium will et bybeusoffs can tak e on m ore com plex ity than a form ed steel t, andpar ing 1 0 to 2 0 percent thinner steel. A s high-h strengt steels are so the direct com parison should also tak e the diffe rence in introduced, their net increm ental cost approachesero z after a functionality into account. A lso, two or m ore parts m ay get period of m aturity. The D OE estim ates that, on age,aver subintegrated into a single part with one m aterial ver sus that of stituting high- strength steel for m ild steel result s in about a net another, and so the subsystem of parts has to be aluated ev increase in m aterial cost of 1 0 percent ( see Carpen ter, 2 0 0 8 ) . for a cost and perform ance com parison. The cost to reduce m ass ( cost per pound of m assuced) red M ost cost- effective m aterials today for reducing ssm are a increases as the am ount of reduced m ass increases. The “low high- strength steel and alum inum . Both m aterials n replace ca

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hanging fruit” of m ass reduction using high- strengt h steel in these com ponents have been light- weighted already ith w basic applications can result in less than a 1 0 percent cost high- strength steel and alum inum where practical. ne nex O t prem ium . H owever, increasingly aggressive reduction of step would be to transition to m ore m agnesium , which com es m ass req uires m ore dificult parts and m aterials se who cost with a cost prem ium of perhaps 5 0 percent or m ver ore thato ex ceeds the 1 0 percent prem ium . F or ex am rcent ple, a 1 for pe alum inum . reduction in m ass can generally be achieved at a mltiplier u of 1 . 0 to 1 . 1 . M ore aggressive applications likuire elymreqore Secondary Savings Beneits ex pensive m aterials or m ore ex pensive fabrication nd joina ing m ethods, or affect the costs of other parts the in vehicle. A n im portant consideration with m ass reduction hatisitst A s the aggressiveness increases ( to 5 percent, ercent, 1 0 p or effects on fuel consum ption can cascade. A s the smof aasveeven 20 percent) , m ore m aterials and processing ions optneed hicle is reduced in, say, the body or interior, oth er com ponents to be considered that further increase cost. The com m ittee of the vehicle can be reduced in siz e as a conseq nce. ue F or believes that a 1 0 percent reduction in m ass isievable ach ex am ple, brak es, fuel system , power train, and crasheven with a m ix of m aterials ( high- strength steels,inum alum, m anagem ent structures can all be downsiz ed for a lighter com posites, and other m etals) for approx im ately 0 0 $per2 . vehicle. In the study conducted by R icardo, Inc.2 , 0( 0 7 ) for pound of m ass elim inated ( see Table 7 . 8 ) . Messive ore aggr the A lum inum A ssociation, the rule of thum ed b generat was reductions will cost m ore than $ 2 . 0 0 per pound. that for every pound elim inated in the vehicle stru cture, an adA lum inum costs m ore than steel and has som e formditional ing 0 . 3 0 lb ( 3 0 percent) of m ass could cedbe in redu other and joining lim itations that prevent its use in som e applicaareas of the vehicle. If this rule of thum b is appl ied and m ass tions. A n increm ental cost of alum inum overody steel b reduction com es at a cost of $ 1 . 6 5 / lb, thendditional at an a parts in the range of 3 0 to 1 0 0 percent has been tim esated 3 0 percent of secondary m ass savings ( 0 . 3 et lb)cost theper n ( Carpenter, 2 0 0 8 ; Bull, 2 0 0 8 ) . The A lum tion inum pound A ssocia becom es $ 1 . 6 5 / 1 . 3 lb, which becom Ites is $ 1 . 2 7 / l estim ates that the average increm ent is 3 0 percent at the low im portant to note that achieving secondary savings typically end ( prem ium cost per pound of m ass elim inated) the . A req t uires reengineering one or m ore system s on ehicle, the v m id- point of this range, the increm ental cost.is6 $5 1/ pound and this would lik ely be perform ed according to the product of m ass elim inated. H igher costs will be incurred approach( developm ent tim ing plan ( see above the section “Tim ing ing $ 2 . 0 0 / lb cost prem ium ) as m ore aggressive tion of reducConsiderations for Introducing New Technologies”) .S o the m ass reduction is attem pted. 3 0 percent secondary beneit is achieved in the long term and The body of a baseline vehicle ( m ostly steel) weigh s apnot necessarily when the initial reduction in m ass is achieved. prox im ately 8 0 0 pounds. A n alum inum - intensive weighs body approx im ately 4 5 percent less, or 4 4 0 pounds. stim The atede Rolling Resistance cost for this savings in weight is in the range of $ 4 6 8 ( $ 1 . 3 0 / lb) to $ 5 9 4 ( $ 1 . 6 5 / lb) . M ass reduction in system other vehicle s The increm ental cost for low- rolling- resistanceestiris essuch as power train, wheels, chassis, and interior would typitim ated to be $ 2 to $ 5 per tire, but there is evidence som e that cally com e at sim ilar or slightly higher increm l cost enta per suggests that these tires m ay slightly com prom topping ise s pound saved. V ehicle interiors ( including seats, ordotrim , distance. One tire m anufacturer suggested that tire s that do headliners, instrum ent panel com ponents, etc. )titute consapnot com prom ise stopping distance or tread wear coul d cost prox im ately one- third of the vehicle m ass ( 1 , 0 0 0 pounds 1 0in ato 2 0 percent m ore than conventional tires. e: The ( Not 3 , 0 0 0 - pound vehicle) . By using lightweight m s, Byron aterial uncertainty about low- rolling- resistance tires withrespect to F oster at J ohnson Controls plans to elim inate 3rcent 0 pe of the increased tread wear and stopping distance is the reason for interior m ass ( F orbes, 2 0 0 8 ) . If the samal ecost increm used ent increasing the estim ated cost beyond the $ 1 . 0 tire 0 per cost for the body is assum ed, approx im ately 3 0 0 lim pounds inated e cited in NR C ( 2 0 0 6 ) . The NR C ( 2 0 0 6 )d study that recogniz e would cost $ 3 9 0 ( $ 1 . 3 0 / lb) to $ 4 9 5 ( $ 1 . 6 5 an / lb)acceptable . increase in tread wear and stopping distance Other opportunistic com ponents in the vehicle inclu de m ight occur. H owever, to elim inate this increase, dditional a the power train, chassis, and wheel com ponents. M y ofan costs can be ex pected over the $ 1 . 0 0 estim ate. )

TA BL E 7 . 8

Com m ittee’s Estim ate of Cost tohicle R educe M ass V ( ebased on 3 , 6 0 0 - lb vehicle)

M ass R eduction L ow Cost/ lb (% ) ($ ) 1 2 5 1 0

1 .2 8 1 .3 3 1 .5 0 1 .8 0

H igh Cost/ lb ($ ) 1 .5 4 1 .6 0 1 .8 0 2 .1 6

A verage Cost/ lb ($ ) 1 .4 1 1 .4 6 1 .6 5 1 .9 8

M ass S aved ( lb) 3 6 7 2 1 8 0 3 6 0

L ow Total Cost ($ )

H igh Total Cost ($ ) 4 6 .0 8 9 5 .7 6 2 7 0 .0 0 6 4 8 .0 0

5 5 .3 0 1 1 4 .9 1 3 2 4 .0 0 7 7 7 .6 0

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ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Vehicle Accessories

a transm ission. A s a result, the num ber of cost im est ates available to the com m ittee was lim ited. W hen onaladditi inTable 7 . 9 shows the com m ittee’s estim atessts of the for co form ation was sought by the com m ittee, the results relected vehicle accessories that could im prove the fuel con sum ption the still- em erging k nowledge base about this transm ission of light- duty vehicles. type. One estim ate, based on a detailed teardownudy st conducted by F EV , Inc. , for the EP A , estim cost ated the Transmission Technologies of 6 - speed D CTs with 3 5 0 N- m torq ue capacity t and we clutches at over $ 1 4 7 less than that for a 6 - autom speed atic The estim ated retail price eq uivalent for each tran sm is( K olwich, 2 0 1 0 ) . H owever, OEM s considering up tooling sion technology is provided in Table 7 . 1 0 . A shewas case t their own eq uivalent units had also m ade carefultim es ates of for the engine technology chapters ( e. g. , Chapters 4 and 5 ) , the high- volum e piece cost increase of D CT6 s. These OEM the baseline for transm ission costs is the 4 - speed autom atic estim ates were that high- volum e D CT6 s would arly cost ne typical of 2 0 0 7 m odel- year vehicles. Cost estim are from ates $ 2 0 0 m ore than 6 - speed autom atics. Thus, the range between the two sources considered ( EEA , 2 0 0 7 ; M artec , Inc.Group , estim ates was approx im ately $ 3 5 0 . A t the m present e, in- ti 2 0 0 8 ) . A s can be seen from Table 7 . 1 0im, the atescost for est suficient inform ation is available to narrow this iwde range. the 5 - , 6 - , 7 - , and 8 - speed autom atic transm replace-ission m ents for the baseline 4 - speed autom atic havesiderable a con num erical range. In addition to the cost estim ates, Table 7 . 1 0 SUMMARY also includes cost estim ates converted to R P E using the R P E There is a range of non- engine technologies with varying m ultiplier of 1 . 5 . Besides the estim ates for, 57 -- ,, 6and costs and im pacts to consider. M any of these techno logies 8 - speed autom atic transm ission replacem ents,tesestim are a are continually being introduced to new vehicle m ode ls also included for D CTs and CV Ts. The D CT estim relect ates based on the tim ing of the product developm ent proc ess. an even wider num erical range than those for the au tom atics. Coordinating the introduction of m any technologieswith F or ex am ple, the 6 - speed autom atic cost estim ange ates r the product developm ent process is critical to m max iz i ing from $ 1 3 3 to $ 2 1 5 , whereas the estim tates clutch, for the we their im pact and m inim iz ing their cost. R elatively m inor 3 5 0 N- m torq ue capacity range from $ 1 4 0 to $ 4 0 0 . changes that do not involve reengineering the vehicle can A lthough D CT units have been in high- volum e producbe im plem ented within a 2 - to 4 - year tim e fram is e. Th tion for a num ber of years, until recently only the V W - A udi could include efforts such as aim ing for m inor redu ctions group, work ing closely with one supplier, has produ ced such

TA BL E 7 . 9

Estim ated Increm ental Costs forccessories V ehicle A That Im prove F uel Consum ption

D escription

S ource of Cost Estim ate

H V A C—variable strok e, increased eficiency ( hum control, iditypaint, glass, etc. ) Electric and electric- hydraulic power steering Therm oelectric energy recovery

a $ 7 0 -$ 9 0 U . S . Environm ental P rotection A gency D eutsche Bank $ 7 0 -$ 1 2 0 S everal hundred dollars

Estim ate

aThe U . S . EP A has estim ated the cost associated im with proving the energy eficiency of the A / C system nd reducing a refrigerant leak age from the system at less than $ 1 1 0 to the consum er ( A NP R - H - Q 0 3- 1OA8 ;RF - R2 0L 0 88 6 9 4 - 2 ) . W ith an R the P E original of 1 . eq 7 5uipm the cost ent to m anufacturer would be just over $ 6 0 .

TA BL E 7 . 1 0 Transm issions

Estim ates of R eplacem ent Costs m ission for Trans Technologies R elative to 2 0 0 7 4 - S peed atic A utom $ Cost ( EEA , 2 0 0 7 )

Transm ission Type 5 - speed autom atic 6 - speed autom atic 7 - speed autom atic 8 - speed autom atic D CT ( dry clutch, 2 5 D CT ( wet clutch, 3 5 CV T ( engine < 2 . 8 CV T ( engine > 2 . 8

1 3 3 1 3 3 1 7 0 — 0 N- m ) 0 N- m ) liter) liter)

— 1 4 0 1 6 0 2 5 3

NOTE: R P E values were determ ined using a cost m plierulti of 1 . 5 .

$ R P E ( EEA , 2 0 0 7 )

$ Cost $ R P E ( M artec, 2 0 0 8 ) ( M artec, 2 0 0 8 )

2 0 0 2 0 5 2 5 5 —

— 2 1 5 —

— 3 2 3 — 6 3 8

4 2 5 — 2 1 0 2 4 0 3 8 0

3 0 0

4 5 0 4 0 0

— —

6 0 0 — —

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

115

NON- ENGINE TECH NOLOGIES

in m ass ( m aterial substitution) , im proving aerodyna m ics, or switching to low- rolling- resistance tires. M substanore tive changes req uire longer- term coordination with the P D P because reengineering and integration with other subsystem s are necessary. This could include resiz ing the power train/ transm ission or aggressively reducing m ass ( e.hanging g. , c the body structure) . S ubstantive changes lik e this will tak e 4 to 8 years to adopt. The cost estim ates provided in this chapter all assum e coordination with the P D P pto contain hel costs and achieve m ax im um im pact. Two im portant technologies im pacting fuel consum on pti addressed in this chapter are light- weighting and rtansm issions. L ight- weighting has alm ost unlim ited al potenti because vehicles can be m ade very light with ex otic m ateria ls, albeit at potentially high cost. The increm ental cost to redu ce a pound of m ass from a vehicle tends to increase as thealtot am ount of reduced m ass increases, leading to a curve with dim inishing returns. A bout 1 0 percent of vehicle m ass can imbe inated el at a cost of roughly $ 7 0 0 ( or about $ 2 . 0 able 0 / lb; 7 .see 1 1T ) If the aggressiveness to reduce m ass increases m uch beyond 1 0 percent, it is necessary to begin addressing bod y structure design ( such as considering an alum inum - intensive ar) , cand the cost per pound increases. A 1 0 percent reductio n in m ass

over the nex t 5 to 1 0 years appears to be within achrefor the typical autom obile, considering the current baselin e. Transm ission technology has signiicantly im proved nd,a lik e other vehicle technologies, shows a sim ilarrve cu of dim inishing returns. P lanetary- based autom atic smtran issions can have ive, six , seven and eight speeds, tbu with increm ental costs increasing faster than their im ctpa on fuel consum ption. Continuously variable transm issions veha been available on the m ark et for a num ber of years,their but rate of im plem entation seem s to have lattened out, sting sugge that future new im plem entations will be lim ited num in ber. D CTs are in production by som e vehicle OEM s V ( e.W g. , / A udi D S G) , and new D CT production capacity has an-been nounced by other vehicle OEM s and suppliers. Ittherefore is ex pected that the predom inant trend in transm ission design will be conversion both to 6 - to 8 - speed planetarybased autom atics and to D CT autom ated m anuals, with CV Ts rem aining a niche application. Because of the close link age . between the effects of fuel- consum ption- reducinggine en technologies and those of transm ission technologies , the present study has considered prim arily the com bined effect of engines and transm ission com binations rather than otential p separate effects.

TA BL E 7 . 1 1 S um m ary of the Com m ittee’s he Costs F indings and Im on tpacts of Technologies for R educing ightL D uty V ehicle F uel Consum ption F uel Consum ption Technology

D escription and A pprox im ate M anufacturing Cost

M ass reduction 1 ( assum e 3 , 6 0 0 5pound vehicle) 1 2 Transm ission

A erodynam ics R olling resistance

Electrical accessories

aW

% ( % ( 0 % 0 %

3 1 ( (

6 8 3 7

lb) ; $ 4 0 lb) ; $ 6 0 lb) ; 2 0 lb) ;

6 2 $ $

-$ 5 5 7 0 -$ 3 2 4 6 4 8 -$ 7 7 8 1 ,6 0 0 +

Com m ents

0 .2 5 M aterial substitution M aterial substitution 3 - 3a . 5 A ggressive m aterial substitution 6 -a7 R edesigned body with alum inum and com posite1 1 -a1 3 intensive structures F ive- speed autom atic transm issions; 3 $ 1 3 2 -3 Can also im prove vehicle perform ance S ix - speed autom atic transm issions; $ 1 3 3 - $ 2 1 5 3 - 5also im prove vehicle Can perform ance S even- speed autom atic transm issions; $ 1 7 0 - $ 3 0 0 5 - n7 also im prove vehicle Ca perform ance Eight- speed autom atic transm issions; $ 4 2 5 6 -8 o im Can provealsvehicle perform ance D ual- clutch autom ated ( D CT) m anual transm 6issions -9 D CTs have replaced original autom ated m anual ( 6 / 7 speed) ; $ 3 0 0 ( dry clutch) , –$ 1 4 - $ 4 0 0 ( wet transm issions clutch < 3 5 0 N- m ) Continuously variable transm issions; $ 1 5 0 ( < 2 1. 8- 7L ) , P ossible engine noise; not applicable to large ngines e $ 2 6 3 ( > 2 .8 L ) 5 to 1 0 % reduction in C of drag) ; 1 -2 W heel well and underbody covers, body shape, d ( coeficient $ 4 0 -$ 5 0 m irrors, etc. ; bigger im pact on highway drive cycle L ow- rolling- resistance tires;rox appim ately $ 1 0 1 -b2 S topping distance and durability can be com prom ised apiece ( $ 3 0 - $ 4 0 ) with inferior m aterials; optim al m aterials drive up costs Tire- inlation m onitor; becom ing standard eq uipm . ent 7 0 D epends on m onitor settings and driver behavior L ow- drag brak es; becom ing standard eq uipm ent 1 ars eq M uipped ost c already today H V A C—variable strok e, ed increas eficiency 3 -4 Current F TP does not capture beneit ( beneits ucedred ( hum idity control, paint, glass, etc. ) ; $ 7 0 - $ 9 0 to 0 . 5 - 1 . 5 % within Table 9 . 1 ) Electric and electric- hydraulic power steering; 1 -5 Electric for sm all cars, electric- hydraulic bigger for $ 7 0 -$ 1 2 0 cars—beneits for the F TP are sm aller ( 1 - 3 % ) .

ith resiz ed power train. percent m ay be feasible with resiz ed powerain. tr

bThree

Im pact on F uel Consum ption (% )

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

116

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

A ccessories are also being introduced to new vehicl es a signiicant increase in costs. The uncertainty andinstabilto reduce the power load on the engine. H igher- efic iency ity of com m odity prices ( e. g. , for carbon iber, ins, res and air- conditioning system s are available that m ore timop ally alum inum versus steel) increase the risk to the icleveh m anum atch cooling with occupant com fort. This includes, for facturer of adopting these new m aterials. ex am ple, hum idity control, air recirculation,ncreased and i com pressor eficiency using a variable- strok e comssor. pre Finding 7 .3 Transmissio : ns.A nother prom ising technology Electric and electric- hydraulic power steering alsoreduces for reducing vehicle fuel consum ption is transm ons issi with the load on the engine by dem anding power ( electric ) only an increased ratio spread between the low and the high gears when the operator turns the wheel, whereas the older technol( e. g. , 6 - 8 speeds) and dual- clutch transm at issions elim thiogy relied on hydraulic power supplied by the engine all the nate torq ue converters. tim e. A n im portant m otivating factor affecting introducthe tion of these accessories is whether or not their im pact is Finding 7 .4 Lo : w er- energ y - l o ss accesso A ries. collecm easured during the oficial CA F E certiication .tests The tion of relatively low- cost vehicle technologies can have a certiication test currently does not tak e the air ocnditioner positive im pact on reducing fuel consum ption. L ollingow- r into account, and so there is little m otivation to im prove its resistance tires, im provem ents to vehicle aerodynam ics, and eficiency and incur added cost; however, this situa tion m ay electric power steering can all cost less than $ 2 0in0total change with newly proposed test procedures. while reducing fuel consum ption by about 1 0 percent , if Estim ates for these technologies and several othersare H V A C is included as a com ponent of real- world ng. drivi sum m ariz ed in Table 7 . 1 1 . The fuel consumm ption ates estiOther technologies that can yield increm ental redu ctions assum e ideal conditions, and there are im portant teraction in in fuel consum ption are increased H V A C com fipressor e effects am ong different technologies. Generally,isitnot posciency, ultraviolet filtering, glaz ing, and cool/flecting re sible to apply two or m ore of the technologies inable T 7 . 1 1 paints, but these technologies are not currently pursued and algebraically add the im pacts on fuel consum on. pti The very aggressively because they are not tak en account of typical im pact from m ultiple technologies will essbethan l in the oficial CA F E certiication tests. It would ak te m ore the sum of their individual fuel consum ption estim tes. a than the addition of H V A C in one of the ive test hedules sc used to report fuel econom y on the vehicle stick to erhave a signiicant im pact on the penetration of these techn ologies.

FINDINGS

Finding 7 .1 R: efresh/ redesig Wn. ith respect to reducing fuel REFERENCES consum ption, recognition of product developm entcess pro tiresrolli ( but watch tim ing is im portant for m inim iz ing the costem of im ent-pl A utom otive News. 2 0 0 8 . A big fuel saver:ngEasy brak ing) . J uly 2 1 . ing m any new vehicle technologies. Only relatively m odest Barrand, J . , and J . Bok ar. R educing tire rolling sistance re to save fuel changes can be m ade when vehicles are restyled, and and lower em issions. S A E P aper 2 0 0 8 - 0 1 -ternational, 0 1 5 4 . S A E secondary beneits from m ass reduction are unlik The ely. W arrendale, P a. reengineering or redesign phases of product developm ent Bull, M . 2 0 0 8 . Eficacy, cost, and applicability lightweight of structures to fuel econom y. P resentation to the Com m ittee the A for ssessm ent of offer the greatest opportunity for im plem enting new fuelTechnologies for Im proving L ight- D uty V ehicle Econom F uel y, J une 3 , saving technologies, and this can occur from 4 toyears 8 W ashington, D . C. after initial introduction. S igniicant changes toower p train Carpenter, J r. , J . , U . S . D epartm ent of Energy, ington, D W . ash C. 2 0 0 8 . Chaland vehicle structure and m aterials can be m ade m e easily or lenges to autom otive com posites. P resentation to erican A mChem istry at this tim e. Council, P lastics D ivision, A rlington, V irginia, y 2 0M . a Finding 7 .2:Mass redu ctio n. R eduction of m ass offers the greatest potential to reduce vehicle fuel consum pti on. To reduce m ass, vehicles will continue to evolve with a broad m ix of replacem ent m aterials that include highngthstre steels, alum inum , m agnesium , and reinforced s. These plastic m aterials will be introduced on a com ponent- by- com onent p basis as com panies m ove up the learning curve and ontinue c to design for them . M ore aggressive efforts to ce redu m ass ( by, say, 5 to 1 0 percent) will req uire system tions solu ( as opposed to m aterial substitution solutions) . A chiev ing a m ass reduction of greater than 1 0 percent ( as high as percent) 2 0 will req uire a signiicant change in vehicle design( such as a shift to an alum inum - intensive body or aggressive use of other higher- cost m aterials lik e carbon iber) and ill incur w

Cheah, L . , C. Evans, A . Bandivadek ar, and J ood. . B. H2 0eyw 0 7 . F actor of Two: H alving the F uel Consum ption of New U tom . S . obiles A u by 2 0 3 5 . L aboratory for Energy and Environm ent,husetts M assac Institute of Technology, October. Com pere, A . L . , W . L . Grifith, C. F . Letrovan. eitten, 2and 0 S 0 1. P. Im proving the F undam ental P roperties of L ignin- BasedonCarb F iber for Transportation A pplications. Oak R idge Nationaloratory. L ab A vailable at http:/ / www. ornl. gov/ ~ webwork s/ cppr/ y2 0 00 11 / 4pres/ 5 . 1pdf. 2 D eutsche Bank . 2 0 0 8 . Electric cars: P lugged tsche in. Bank D eu Global M ark ets R esearch R eport. J une 9 . EEA ( Energy and Environm ental A nalysis, Inc.. ) U. 2pdate 0 0 for 7 A dvanced Technologies to Im prove F uel Econom y of L ightVD ehicles—F uty inal R eport. P repared for U . S . D epartm ent of ober. Energy. Oct EP A ( U . S . Environm ental P rotection A gency) P A . 2S 0taff 0 8Techni. E cal R eport: Cost and Effectiveness Estim ates of Tec hnologies U sed to R educe L ight- D uty V ehicle Carbon D iox ide ns.Em EP issio A 4 2 0 R - 0 8 - 0 0 8 . A nn A rbor, M ich. F orbes. 2 0 0 8 . A utom ak ers’ natural appeal, gazF ine, orbes SM eptem a ber 2 6 .

In

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

NON- ENGINE TECH NOLOGIES

117

Gessat, J . 2007 . Electrically powered hydraulicering ste system s for light M artec Group, Inc. 2 0 0 8 . V ariable Costs ofnom F uely Eco Technologies. com m ercial vehicles. S A E P aper 2007 - 01 - 41ternational, 9 7 . S A E In P repared for A lliance of A utom obile M anufacturers. J une 1 ; am ended W arrendale, P a. S eptem ber 2 6 and D ecem ber 1 0 . Goodyear Tire & R ubber Com pany. 2 0 0 9 . L etter fromnley,D onaldNR S taC ( National R esearch Council) . 2 0 0 2 . Effectivenes s and Im pact of CorV ice P resident, P roduct Q uality and P lant Technolog y, A pril 1 3 , 2 0 0 9 ; porate A verage F uel Econom y ( CA F E) S tandards. ngton,WD ashi . C. : e- m ail ex changes with D onald S tanley, J anuary, 2 0 02 98 ,, and F ebruNational A cadem y P ress. ary 2 5 , 2 0 0 9 . NR C. 2 0 0 6 . Tires and P assenger V ehicle F uel : Inform EconomingyConH erem ans, J . P . , V . J ovovic, E. S . Toberer, t, KA . .KS urosak aram ai, A . sum ers, Im proving P erform ance—S pecial R eport ashington, 2 8 6 . W Charoenphak dee, S . Y am anak a, and G. J . S. nyder. Enhancem 2 0 0ent8 of D . C. : The National A cadem ies P ress. therm oelectric eficiency in P bTe by distortion of he telectronic density P agerit, S . , A . R ousseau, and P . S harer.econom 2 0 0 6y .sensitivity F uel to of states. S cience 3 2 1 :5 5 4 . vehicle m ass for advanced vehicle powertrains. S A P aper E 2 0 0 6 -0 1 H ussain, Q . , C. M aranville, and D . Brigham herm. 2oelectric 0 0 9 .exT haust 0 6 6 5 . S A E International, W arrendale, P a. heat recovery for hybrid vehicles. S A E P aper 2 10 -01 93 - 20 7 . S A E InterP owers, W . 2 0 0 0 . A utom otive m aterials entury. in theA2 dvanced 1 st c national, W arrendale, P a. M aterials and P rocesses, M ay. IBIS A ssociates. 2 0 0 8 . Beneit A nalysis: U inum se of AS tructures lum in R icardo, Inc. 2 0 0 7 . Im pact of V ehicle W ion eight on FR uel educt Econom y Conjunction with A lternative P ower Train Technologies in A utom obiles. for V arious V ehicle A rchitectures. P repared A for lum the inum A ssociaIBIS , W altham , M ass. tion, Inc. K olwich, G. 2 0 1 0 . L ight- D uty Technology Cost is—RA eport nalyson R ugh, J . P . , L . Chaney, J . L usbader, J . ustagi, M eyeer, K .M Olson, . R and R . A dditional Case S tudies. P repared for U . S . Environm ental P rotection K ogler. 2 0 0 7 . R eduction in vehicle tem peratures fuel useand from cabin A gency. F EV , Inc. , A uburn H ills, M ich. ventilation, solar- relective paint, and a new solar - relective glaz ing. S A E P aper 2 0 0 7 - 0 1 - 1 1 9 4 . S A E International, le, P a. W arrenda

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

8 Modeling Improvements in Vehicle Fuel Consumption

INTRODUCTION

2 0 0 9 ) , are P D A m odels that use data on osts technology c and fuel consum ption im pacts from a variety ofces, sour The potential of technology to reduce fuel consum pt ion including F S S m odels. can be estim ated in three basic ways. One approach involves This chapter evaluates m ethods of estim ating thetenpo constructing an actual prototype vehicle with the technolotial to decrease autom otive fuel consum ption by nging cha gies in q uestion, perform ing the Environm entalection P rot vehicle design and technology. It begins with som gene A gency ( EP A ) city and highway dynam om eter eattests rep eral observations on m odeling technologies’ potenti al for edly, and then m easuring the fuel consum ption. ough A lth reducing fuel consum ption. Because of the technolog ical there is som e variability from test to test, this ethod m is the com plex ities of vehicle system s, predicting howbinacom m ost accurate but is also prohibitively ex pensive. A second tions of technologies m ight perform in new vehicle designs approach is to construct a com puter m odel that repr esents involves uncertainty. The present com m ittee sum m ariz es and all of a vehicle’s com ponents and their interaction s, includdiscusses the m ethod used by the National R esearch Council ing representations of the technologies for reducing fuel ( NR C) Com m ittee on the Effectiveness and Im Corpact of consum ption, and to sim ulate the behavior of thehicle ve porate A verage F uel Econom y ( CA F E) S tandards 2 0 0in2its over the federal test procedures. This m ethod, whic h the report ( NR C, 2 0 0 2 ) . It then goes on to comevaluate pare and com m ittee refers to as full system sim ulation, (isFnow S S ) the two m ost widely used approaches to estim ating he techt the state of the art throughout the autom otive indu stry for nological potential for reducing fuel consum ption—P D A and m odeling fuel consum ption. A lthough it is lessnsive, ex pe F S S . Both m ethods are described in detail, and ications appl F S S still req uires very large ex penditures ofand timm eoney of the two m ethods to various types and coniguratio ns of if it is used to calibrate m odels to the 1 , 0 0 o0 different or s vehicles are com pared. A lthough it was able to museful ak e vehicle conigurations offered for sale in the U nite d S tates com parisons between m odeling m ethods, the com m ittee each m odel- year and to test all relevant com binatio ns of techfound that inform ation com paring the results ofher eit the nologies. The third alternative is to construct an algorithm F S S or the P D A m ethod to real- world vehicles rce. The is sca that adds discrete technologies to the set of base-year vehicle com m ittee also com m ents briely on the m ethodology sed u conigurations and that then calculates their cum ula tive im by the NH TS A in its 2 0 1 1 F inal R ule. pact while attem pting to account for interactions etween b R ecogniz ing the lim itations of all m odeling approac hes, them by m eans of adjustm ent factors. The com refers m ittee the com m ittee considers the F S S m ethod toate beof the st to this third m ethod as partial discrete approx im ion at (P D A ). the art and therefore the preferred m ethod for esti m ating The sim plicity of the third approach allows fuel consum ption the potential of technologies to reduce fuel consumption. im pacts to be calculated for thousands of vehiclesand tens H owever, given the cost of F S S m odeling at present, the of thousands of technology com binations. The k eyestion q u com m ittee believes that the P D A m ethod, ecuted properly ex is whether the third m ethod can be ex ecuted withficient su and supplem ented with estim ates of technology inter action accuracy to support fuel econom y regulation. The V lpeo effects developed by F S S or lum ped param eterng, m can odeli M odel ( V an S chalk wyk et al. , 2 0 0 9 ) , ional used by the Nat be a reasonably accurate m ethod for assessing theotential p H ighway Trafic S afety A dm inistration ( NH TS A ) in its for reducing light- duty vehicle fuel consum ption er ova tim e rulem ak ing analyses, and the EP A ’s OM EGA m d odel, use horiz on on the order of 1 0 years. by the EP A in its rulem ak ing analysis ( EP A and A ,NH TS

118

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

MODELING IMP R OV EMENTS IN V EH ICLE F U EL CONSU MP TION

CHALLENGES IN MODELING VEHICLE FUEL CONSUMPTION

119

1 . D ifferences between the attributes of the repre sentative or typical vehicle being analyz ed and the actual vehicles it represents; 2 . Inaccuracies in the characteriz ation of the bas e vehicle, especially its energy lows; 3 . Inaccurate assessm ent of technology im pacts, clud-in ing the inability to fully represent the physics of a new technology in F S S m odeling; 4 . D ifferences in the im plem entation of a given chnol-te ogy from vehicle to vehicle; 5 . Changes in the nature of a technology over tim; and e 6 . Inaccurate estim ation of the synergies am ong ch- te nologies and how they contribute to the overall end 1 result of their com bined application.

A long with the m any potential beneits of using com uter p m odels to understand vehicle system s com e limns itatio as well. In addition to enabling insight into how an overall vehicle system m ight operate, vehicle system m ng can odeli also help m easure the interactions between vehicula r subsystem s and how they affect overall vehicle perform ance. A n understanding of the physics underlying these interactions is im portant when trying to estim ate how future vehicl es m ight perform with different com binations of technologies . A ll m odels are inherently sim pliications of reality;e physics th of real processes will always be considerably m ore com plicated than that relected in a m odel. In the end, pacts im can only be k nown with certainty when a technological ocncept In general, rigorous, q uantitative assessm ents hese of t is realiz ed in a real vehicle, and even then realiz ations of potential sources of error and their im pacts on the potential the sam e technological concept can differ from one vehicle to reduce vehicle fuel consum ption are scarce. to another. The m eaningful q uestion is whether any given In this chapter com parisons of the results of F S nd S a m odel or m ethodology has suficient idelity to com tentpe P D A ( with lum ped param eter m odeling) areInpresented. ex ecutions of the technological concept to achievethe goals addition, the com m ittee contracted with R icardo, c. , to In for which the m odel has been developed. perform a statistical analysis of F S S m odeling. goalThe W ith even the m ost com plex and com prehensive s, m odel was to determ ine whether a lim ited num ber of F nsS S ru there are challenges when m odeling ak no w vehicle n could be used to generate accurate data on the m aineffects coniguration, and even greater challenges when trying to of technologies and their interactions, which could then be predict the behavior of future vehicles using new com binaused as basic input data for P D A m odeling. The lts of resu tions of technologies. W hen m odeling a k nown sting or ex i the analysis support the feasibility of this concept. U nfortuvehicle the principal problem s are in capturing the desired nately, scientiic data about the accuracy of eitherm odeling dynam ics to a suficient level of detail or idelity, and in colm ethod in com parison to actual vehicles are very m liited. lecting and inputting representative param eters or boundary conditions. The advantage of m odeling a k nown vehic le is METHODOLOGY OF THE 2002 NATIONAL RESEARCH that data on the vehicle’s actual perform ance are sually u COUNCIL REPORT available to the m odeler, and the data can be used to tune or validate the m odel’s perform ance. Even for ex ingist The 2 0 0 2 NR C Effectiveness report and Imp act o f Co rp o vehicles, however, ex perim ental data sets are freqlyuent rate Averag e F u el Eco no my Standards used a type of P D A sparse and m ay not include the precise perform ance situm ethod to estim ate the potential future reductions of fuel ations of interest. consum ption by light- duty vehicles. The 2 0 0 2 tee com m it D etailed com puter m odeling of vehicle system es can b recogniz ed the ex istence of synergies am ong technol ogies very ex pensive. D eveloping suficient data on therforpe applied to reduce fuel consum ption but did not prov ide ex m ance of engines and other com ponents, data that e not ar plicit estim ates of the effects of such interaction s. Technologenerally available in the open literature, is a m jor a source of gies were im plem ented in deined seq uences called ths,pa the ex pense of F S S m odeling. A n autom obile m com ight pany and the im pacts of technologies on fuel consum ption were spend m any tim es the resources available to the com m ittee to adjusted to account for interactions with other technologies develop dynam ic m odels to help answer the k inds q of uespreviously adopted. tions posed to the com m ittee. On the order of 1 different ,0 0 0 vehicle conigurations undergo fuel consum ption test ing each m odel year. F S S m odeling of even the m is-ost prom ing com binations of advanced technologies for such a large 1 In this report the com m ittee chose to use the term sy nerg ies as deined in num ber of vehicles would be ex pensive for federal gencies. a the joint EP A and NH S TA “P roposed R ulem ablish ak ing L toightEst D uty V ehicle Greenhouse Gas Em ission S tandards and Corpo rate A verage F uel P D A m odeling, on the other hand, can be im plem in ented 0 9technologies ) . Two or m o sim pliied algorithm s that can estim ate fuel consum tion p Econom y S tandards” ( EP A and NH TS A , 2 0 re applied together m ight be negatively synergistic, eaning m that the sum of potentials for thousands of vehicles or m ore, consi dering their effects is less than the im pact of the indivi dual technologies ( contribvirtually all logical com binations of technologies. utes less to reducing fuel consum ption, in this cas e) , or m ight be positively There are at least six sources of error in estim ng ati the synergistic, m eaning that the sum of the technologi es’ effects is greater than the im pact of the individual technologies ( in this case, contributes m ore to potential to reduce vehicle fuel consum ption: reducing fuel consum ption) .

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

12 0

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Technology changes m odify the system and hence have com plex effects that are dificult to capture and alyz an e. It is usually possible, however, to estim ate the pacts im of speciic technologies in term s of a percentage savin gs in fuel consum ption for a typical vehicle without a full ex am ination of all the system - level effects. ( NR C, 2 0 0 2 , p. 3 3 )

and possible tradeoffs with other vehicle attributes. R anges were given for costs in order to relect m anufacture r- speciic conditions, m ark et uncertainties, and the potential for evolutionary costs reductions for new technologies. The 2 0 0 2 com m ittee did not specify a conidence interval for the ranges, nor did it ex plicitly address interdependen cies or synergies of perform ance or cost, ex cept via the crem in ental F or each technology assessed, the com m ittee estim ed notat effects of seq uential application in the technology paths. only the increm ental percentage im provem ent inconfuel The increm ental fuel consum ption im provem ent tail and re sum ption . . . but also the increm ental cost pplying that a the price eq uivalent estim ates in Table 8 . 1 are additiv e but only technology would add to the retail price of a vehicle. ( NR C, for a particular technology path. The technologies included 2 0 0 2 , p. 3 5 ) in a path are indicated by an “X ” in the colum nsbeled la 1 , , and 3 . Technologies not contained in a path were not to The 2 0 0 2 NR C com m ittee grouped technologies 2into be added to that path. A range of estim ates is prov ided for three categories: engine technologies, transm ission technoloboth fuel consum ption and cost im pacts. H owever, ly the on gies, and vehicle technologies. V ehicles were group ed into 1 0 m idpoints of those estim ates can be directly accum latedu( as classes. Table 8 . 1 is the 2 0 0 2 com m technologies ittee’s list of illustrated in F igure 8 . 1 ) , since accum ulation ll theofhigha for passenger cars, including ranges for the estim ted a increend or low- end estim ates without adjustm ent would roduce p m ental reductions in fuel consum ption and for incre m ental m isleading results. R P E im pacts. The 2 0 0 2 NR C com m ittee’s m ethod received - som e criti F or each vehicle class three different seq uences of technology im plem entation, called “production developm t en cism for being overly sim plistic. One notable critiq ue ( P atton paths, ” were m apped out. F igure 8 . 1 shows imf the pacts o et al. , 2 0 0 2 ) cited three m ajor issues: technologies included in the three paths for passenger cars, 1 . F ailure to ex am ine system - level effects; as noted in Table 8 . 1 , on the fuel consum ptionmof aidsiz e 2 . Inaccurate fuel consum ption estim ates for idual indiv car. The paths were intended to provide a logical seq uence technologies; and of im plem entation of the various technologies and o ensure t 3 . Overcounting of fuel consum ption reductions. that the increm ental fuel consum ption reductionsomfr a given technology could be estim ated conditional onthe The irst point chiely faulted the 2 0 0 2 com m r ittee fo technologies that had preceded it. P aths 1 and 2m coprised m ultiplying together the im pacts of individual tech nologies proven technologies that could be introduced within the nex t 1 0 years ( from 2 0 0 2 ) , with P ath m 2 including e m ore soas if they were independent. It observed that whentechnologies address different energy- loss m echanism s,r im thei pacts costly technologies than P ath 1 . P ath 3 included ditional ad em erging technologies the 2 0 0 2 com m ittee believed ould wgenerally are independent, but when technologies address the sam e energy- loss m echanism ( e. g. , engine pum sses)ping , lo becom e available within the nex t 1 5 years. The of em list ergthe aggregate effect m ay be m ore com plex . Thettee com m i ing technologies included several technologies that are now believed that it had addressed this issue by estim ting a the in use ( intak e valve throttling, autom ated m anual ransmt isa speciin sion, advanced continuously variable transm issions ( CV Ts) , increm ental effects of technologies im plem ented ied order. H owever, that com m ittee neglected ntify to q ua integrated starter/ generator, electric power steeri ng) and the energy losses addressed by each technology and did not several that are still not available ( cam less valve actuation, gies. variable com pression ratio engine) . In addition,e th 2 0 0 2 separately q uantify the interactions am ong technolo The second critiq ue covered a variety of points including com m ittee judged that the potential for dieselsmto eet tighter the degree of optim ism in studies cited to support the com em issions standards was highly uncertain and alsoxe cluded m ittee’s estim ates and inadeq uate attention todepenthe hybrids from its q uantitative assessm ent due toertainty unc dence of fuel consum ption im pacts on the characteri stics of about their future potential. H owever, both technol ogies are the vehicle to which they are applied. now available on m ass m ark et vehicles in the U Snited tates. In estim ating the potential reduction in fuel consu m pA n ex am ple of this is cylinder deactivation. Aing ccord to tion ( gallons per 1 0 0 m iles) of each technology, e 2 0 th0 2 the report, cylinder deactivation is “applied to rather large com m ittee drew on a variety of sources of informon,ati engines ( > 4 . 0 L ) in V 8 and V 1 2 conigurations. the re- ” Y et from published reports to presentations to the comittee m by port applies the sam e fuel consum ption reduction ctor fa for ex perts and consultations with autom otive m anufactu rers and cylinder deactivation to vehicles with six and fourcylinder suppliers. H aving studied the available inform ation, the 2 0 0 2 engines, where the actual beneit would be sm aller. ( P atton com m ittee used its own ex pertise and judgm ent cide to de on et al. , 2 0 0 2 , p. 1 0 ) ranges of estim ates for each technology. The ranges were intended to relect uncertainties with respect to the technology H owever, the 2 0 0 2 com m ittee applied cylinder va- deacti of the baseline vehicle, effectiveness of the im ple m entation, tion only to large passenger cars, m idsiz e and larg er sport

F uel Consum ption Technology M nger atrixCars : P asse

—

—

3 5

2 1 0 1 0 5 2 1 0

7 0

3 5 0

M T) 0 -2 1 -2 4 -7 1 .5 - 2 .5 3 -4

2 1 0 2 8 0 2 1 0

0

1 4

1 4 0

7 0 1 4 0

7 0 1 1 2 8 4 3 5 0

3 -5

2 -5

3 5 8

3 -6 5 -1 0 2 -6

−3 to −4

1 -2 1 - 1 .5

2 -3 4 -8 1 -3 1 -2

2 -3 1 -2 3 -6 1 -2 5 -7

1 -5 1

1 5 0 3 5 0

2 8 0

8 4 0

4 2 0 5 6 0 4 9 0

0

5 6

2 8 0

1 5 4 3 5 0

1 4 0 2 1 0 2 5 2 1 1 2 5 6 0

3 5 0

2 78 00

1 4 0

7 0

1 0450

1 4 0 1 1

X

1

1

X

X

X

2

X

X

X

X

X

X

X

X

X

X

X X

X

X

X

3

S ubcom pact

X

X

X X

X

X X

X X

X X

X

1

X

X

X

X

X

2

X

X

X

X

X X

X

1

X X

X

X

X

X

X

X

X

2

X

X X

X

X

X

X

X

X

X

1

X

X

X

X

X

X

X

X X

X

X

X

X

X X

X

X

X

X

X

X X X

X

3

M idsiz Le arge

X X

X X

X

X X X

X

X

X X

X

X

X

X

X

X

X

X

X

3

Com pact

X

X

X

X

X

X

X X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

3

X

X

X

X

X

2

MODELING IMP R OV EMENTS IN V EH ICLE F U EL CONSU MP TION

NOTE: A n X m eans the technology is applicableetoparticular th vehicle. S afety weight added ( EP A line base + 3 . 5 % ) to initial average m ileage/ consum values.ption S OU R CE: NR C ( 2 0 0 2 ) , Table 3 . 1 .

P roduction- intent engine technology Engine friction reduction L ow- friction lubricants M ultivalve, overhead cam shaft ( 2 - V vs. 4 - V ) V ariable valve tim ing ( V V T) V ariable valve lift and tim ing Cylinder deactivation Engine accessory im provem ent Engine supercharging and downsiz ing P roduction- intent transm ission technology F ive- speed autom atic transm ission Continuously variable transm ission A utom atic transm ission w/ aggressive shift logic S ix - speed autom atic transm ission P roduction- intent vehicle technology A ero drag reduction Im proved rolling resistance S afety technology S afety weight increase Em erging engine technology Intak e valve throttling Cam less valve actuation V ariable com pression ratio Em erging transm ission technology A utom atic shift/ m anual transm ission ( A S T/ A A dvanced CV Ts—allows high torq ue Em erging vehicle technology 4 2 - V electrical system Integrated starter/ generator ( idle off- restart) Electric power steering V ehicle weight reduction ( 5 % )

R etail P rice Eq uivalent ( $ ) Baseline: overhead cam s, 4 - valve, ix ed tim er ing, inger roll F uel Consum ption follower Im provem ent ( L % ow ) H igh

TA BL E 8 . 1

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

12 1

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

12 2

F IGU R E 8 . 1

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Estim ated cost of fuel consum tion ptioninreduc m odel- year 1 9 9 9 m idsizOU e cars. R CE: S NR C ( 2 0 0 2 ) , F igure 3 . 6 .

utility vehicles ( S U V s) , m inivans, and pick s. Nearly up truck et al. ( 2 0 0 2 ) attributed essentially all of the 2 0 0 2 com m ittee all of these vehicles have engines with six or m ore cylin4 to 8 percent beneit to reduction in pum ping loss ( and even ders. Cylinder deactivation is applied today to six- cylinder added an additional 0 . 5 to 1 . 0 percent to pumossping reducl engines. Nonetheless, the 2 0 0 2 com m ittee’s rizcharacte ation tion that com pensated for reduced transm ission efic iency) . of baseline vehicles was based solely on the typical attributes Only a 0 . 0 to 0 . 5 percent beneit was assignedcreased to in of the 1 0 vehicle classes. U sing the average charac teristics of therm al eficiency, presum ably due to operating engine the 1 0 classes of vehicles will lead to a certain degre e of error if in a m ore eficient portion of the engine m ap m fore theo the resulting estim ates are applied to the vehicles of speciic tim e. L ik ewise, m ost of the beneits of 5 - speed 6 - speed and m anufacturers. autom atic transm issions ( versus 4 - speed) were buted attri to The criticism of inadeq uate attention to individual vereducing pum ping losses with no beneits for engine therm al hicle characteristics can also be leveled at the 2 0 2 NR C eficiency. S im ilarly, 4 . 0 to 6 . 0 percent of m the ittee’s com com m ittee’s costs estim ates. The costs of fuelum cons ption estim ated 5 . 0 to 7 . 0 percent beneits of engine tingboos and technologies in the 2 0 0 2 NR C report were the sam or all e f downsiz ing was attributed to reduced pum ping losses . The vehicle classes. In fact, the costs of m any technol ogies scale 2 0 0 2 com m ittee, on the other hand, judgedtechthat the directly with m easurable vehicle attributes such asweight nology derives m uch of its beneits from increased ngine e or cylinder count. eficiency at light load due to engine downsiz ing and, when The third critiq ue is that the 2 0 0 2 NR C com m ittee’s possible, reduced friction due to reduced cylinder count at estim ates overstated the potential beneits of techn ologies eq uivalent power. The 2 0 0 2 com m ittee asserted the that that prim arily addressed pum ping losses because m the ethenergy eficiency beneits of m ultivalve, overhead m ca shaft odology did not tak e into account the theoretical im l its of engines derived from four different sources: 2 pum ping loss reduction. The application of single and double overhead cam esigns, d U sing their own judgm ents about the allocationhe of bent with two, three or four valves per cylinder, offersthe poteneits of technologies to reduction of pum ping losses , P atton et al. ( 2 0 0 2 ) divided the 2 0 0 2 com m sum ittee’s ption fuel con tial for reduced frictional losses ( reduced m ass danroller followers) , higher speciic power ( hp/ liter) , engine downbeneit estim ates into six categories of energy loss es. P atton 2 P atton et al. ( 2 0 0 2 ) estim ated the theoretical its at between lim a1 3 percent and 1 7 percent reduction in fuel consum n, ptiodepending on the vehicle in q uestion. The U . S . EP A ( 2 0 0 8pum b) estim ping plus ated friction losses at between 1 0 percent and 1 3 percent for ualactvehicles, assum ing a gross indicated engine eficiency of 3 7 percent.

siz ing, som ewhat increased com pression ratios,reduced and pum ping losses. ( NR C, 2 0 0 2 , p. 3 6 )

P atton et al. ( 2 0 0 2 ) disagreed, assigning 20 . 0 to 5 . percent of the com m ittee’s estim ated 2 . 0 tocent 5 . 0 per

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

12 3

MODELING IMP R OV EMENTS IN V EH ICLE F U EL CONSU MP TION

im provem ent to reduced pum ping losses, while adding a MODELING USING PARTIAL DISCRETE 0. 5 to 1 . 0 percent beneit in therm al eficiency, set off by APPROXIMATION METHOD a −0. 5 to −1 . 0 percent eficiency l o ssdue to increased The P D A m ethod increm entally adds discrete fuelfriction. consum ption- reducing technologies to a baseline veh icle W hile the benefits of variable valve tim ing andt lif until certain criteria are m et. The m ethod is som im et es ( V TV+ L ) are largely reductions in pum ping losses, ey th applied to individual vehicles but m ore often assum es that also include im proved power, and the beneits of cyl inder the fuel consum ption im pact and cost of a technolog y will deactivation include increased engine load ( operation in a be approx im ately the sam e for all vehicles within t least a a m ore eficient region of the engine m ap) as well reduced as subset ( or class) of light- duty vehicles. In a pres entation to pum ping losses. Estim ates of the beneits of therem afo enthe com m ittee, K . G. D uleep of Energy and Environm tal en tioned technologies generated by F S S m odels have oduced pr A nalysis, Inc. ( EEA ) identiied three im portant s in area results consistent with the 2 0 0 2 NR C com mtim ittee’s ates. es which the P D A m ethod, and especially its applicatio n in the R ecent estim ates from the D OT/ NH TS A ( 2 0 0 9 ) and the 2 0 0 2 NR C study, had com e under criticism 0( D 0 8uleep, ). 2 EP A ( 2 0 0 8 a) are com pared with the 2 0 0 2 e’sNR C com m itte estim ates in Table 8 . 2 . The chief area of disagreem ent is the 1 . A deq uate deinition of baseline vehicles; beneit of cylinder deactivation applied to m ultival ve, over2 . Order of im plem entation of fuel consum ption h- tec head cam shaft engines with V V T and discrete orinuous cont nologies; and lift control. The NH TS A estim ated a beneit of o 00 ..50 t 3 . A ccounting for synergies am ong fuel consum ption percent, whereas the NR C and the EP A estim ated itsbene technologies. of 3 to 6 percent. The critics of the 2 0 0 2 NR C report’s m ethodology k e m a The chief disadvantage of the P D A m ethod is is that it an im portant and valid point in calling attentionotthe lack entirely em pirically based and therefore does notxe plicitly of a rigorous relation between the estim ates of fue l consum prepresent the interactions am ong any set of technol ogies. tion reduction and the physical energy lows in a vehicle. A s S ynergies am ong technologies are estim ated by engin eering a conseq uence, the plausibility of the 2 0 0 2 NR im Cates est judgm ent or by m eans of sim pliied analytical tools, such relied heavily on the ex pert judgm ent of the com m ittee m em as lum ped param eter m odels of vehicle energy use uleep, (D bers. The 2 0 0 2 NR C study’s m ethod also didicitly not ex pl 2 0 0 8 ; S ovran and Blaser, 2 0 0 3 , 2 0 0 6 sim ) . Com putation account for the current use of the identiied fuel econom y plicity and the ability to q uick ly and econom ically process technologies in ex isting vehicles. P ractitioners the of P D A inform ation on thousands of individual vehicles and doz ens m ethod can and often do account for energy constrai nts usof alternative com binations of technologies are the m ethod’s ing sim pliied m odeling m ethods called “lum pedeter” param chief advantages. m odels, based on m ethods developed by S ovran and hn Bo The m ain steps in the P D A process are the following : ( 1 9 8 1 ) and ex tended by S ovran and Blaser ( 62 )0 and 0 3 , 2 0 0 reviewed in Chapter 2 of this report. F S S m herently odels in 1 . Identify discrete technologies with fuel consum ption account for energy lows and ensure that physical lim its will reduction potential. not be violated.

TA BL E 8 . 2 Com parison of Beneits of V alve Train nologies Techas Estim ated by NR C ( 2 0 0 2 ) , NH R TS ule A for ’s F inal 2 0 1 1 , and the EP A Technology

NR C ( 2 0 0 2 ) ( % )

M ultivalve OH C 2 V ariable valve tim ing 2 V ariable valve lift and tim ing 1 Cylinder deactivation 3 -6 Sub total 3 -6 Intak e valve throttlingb T otal c 5 -1 Cam less valves aNH

-5 -3 -2

0

M idpoint ( %a ()% ) NH TSMA idpoint ( % )

3 .5 2 .5 1 .5 4 .5 1 2 4 .5 1 6 .5 7 .5

1 3 1 0 .0

- 2 .6 -5 .5 - 3 .5 - 0 .5

1 .8 4 2 .5 0 .2 5 8 .5

1 .5 - 3 .5

2 .5 1 1

NA

NA

EP A ( % ) NA 2 -4 5 3 -4 6 1 2.5 1 -2 1 4 5 -1 5

M idpoint ( % ) NA 3 3 . 6 1 .5 1 0

TS A ’s fuel consum ption beneits are path dependent . The path shown here is for dual overhead cam shaft engines. NH TS A ’s term inology IV T is continuously valve variable lift ( CV V L ) and is a substitute for discrete variable valve lift ( D V V L ) . NH TS A argues that cylinder deactivation applied to CV V L has little neit besince pum ping losses have already been greatly reduced. Others argue that this m isses the beneit of increased engine eficiency at higher load when a six - cylinder engine is operated on only three cylinde rs. cEffect of cam less valve actuation is increm entalvariable to valve lift and tim ing not to intak e valve throttling. The two are m utually ex clusive. S OU R CE: Based on data in NR C ( 2 0 0 2 ) , D OT/ 9 )NH , and TSEPA A ( 2( 20 00 0 8 a) . bIn

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

12 4

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

2. D eterm ine the applicability of each technology. select technologies that m eet all of the followingthree 3 . Estim ate each technology’s im pact on fuel consu m pcriteria: tion and cost. 4. D eterm ine im plem entation seq uences based on 1 . Technologies already incorporated in at leastne o m assa. Cost- effectiveness and produced vehicle som ewhere in the world or preprob. Engineering and m anufacturing considerations. duction technologies judged to have a strong lik eli hood 5 . Identify and estim ate synergistic effects of widespread adoption within the nex t decade; a. Based on em pirical data and ex pert judgm ent, 2 . Technologies having no signiicant negative im ct,pa b. U sing a sim pliied m odel of vehicle energys low or a beneicial im pact on attributes that are valuedby ( e. g. , lum ped- param eter m odel) , or consum ers or that are necessary to m eet safety and c. U sing estim ates from F S S m odels. em issions regulations; and 6 . D eterm ine the “optim al” fuel consum ption by level 3 . Technologies whose cost does not far ex ceed the potena. U sing a com puter algorithm that seq uentially applies tial value of fuel savings and other private and social technologies, beneits. b. U sing fuel consum ption cost curves. F or ex am ple, all but a few of the technologiesidered cons by the 2 0 0 2 NR C study were already in m ass on. producti In Identifying Technologies That Reduce Fuel Consumption general, P D A studies are m ost reliable whenethey lim arited The P D A m ethod, lik e the F S S m ethod, ebeginstowith th technologies already in production. H owever, the farther identiication of distinct technologies that have the potential one m ust look into the future the less tenable this constraint to reduce vehicle fuel consum ption at a realisticost. c 3 The becom es. list of all possible technologies with som e potenti al to reduce fuel consum ption could range from lower- rolling-stance resi Determining Applicability tires and im proved engine lubricants to hum an- powered vehicles and the com pressed air engine. W hen the rpose pu Not every technology will be applicable to every vehicle. is regulatory rulem ak ing, not all possible fuel sum con ption Torq ue lim itations, for ex am ple, have so farted preven the technologies should be included. The world record for autouse of CV Ts in the largest, m ost powerful light-y vehicles. dut m otive fuel econom y is held by the P ac Car II,el-a cellfu Engine downsiz ing by reducing the num ber of cylinde rs with powered vehicle that won the 2 0 0 5 S hell Ecom arathon in turbo- charging m ay be considered applicable to six cylinder L adoux , F rance, with a gasoline eq uivalent fuel nom ecoy of engines but less so to four- cylinder engines due tovibration 4 The 1 2 , 6 6 6 m iles per gallon. three- wheel vehicle accom m o- and harshness considerations. A pplicability appears to be dates one sm all passenger, who m ust drive lying n. dow The largely a m atter of ex pert judgm ent, determ ined a caseon 0 . 5 7 - m wide, 0 . 6 1 - m high, 2 . 7 8 - modylong carboniber b The applicability step reduces the ull by- case basis. f set of has no room for cup holders, not to m ention airditioning. con technologies to only those that can be used on the baseline It is a z ero- em ission vehicle, but m eeting safety tandards s vehicle being considered. was not a design consideration. Clearly m uch of the P A C Car II’s fuel econom y was achieved by m ak ing unacce ptEstimating Fuel Economy and Cost Impacts able tradeoffs with other vehicle attributes. The CA F E law req uires that fuel econom y standards m ust be techno logically F uel consum ption im pacts are estim ated for each hnol-tec feasible and econom ically practicable. This is ulti m ately a ogy and each class of vehicles ( or each individualvehicle) m atter of ex pert judgm ent, yet there is rem ark agreem able ent to which it is applicable. P ractitioners of the P Dm Aethod am ong diverse studies on the list of relevant techn ologies. derive their estim ates from a variety of sources.nlik Ue M ost assessm ents assum e no reduction in siz e eror pow toF S S , the P D A m ethod, by itself, is notuce ablefuel to prod weight ratios as a prem ise. consum ption im pact estim ates for individual technol ogies. It In general, studies of fuel consum ption potential ntended i is a m ethod of aggregating the fuel consum ption im acts of p to inform the regulatory process and using the P Dm Aethod various technologies and m ust obtain the individual technology beneit estim ates from other sources. In itsort repto the com m ittee, EEA cited three principal sourcesorm of infation on fuel econom y beneit. 3 The CA F E guidance states that fuel econom y standar ds should be set at the m ax im um feasible level, tak ing into ation consider technological feasibility, econom ic practicability, the effectother of federal m otor vehicle standards on fuel econom y, and the need of the nati on to conserve energy ( M otor V ehicle Inform ation and Cost S aving le A Vct,, Tit Chapter 3 2 9 , S ection 3 2 9 0 2 [ a] ) . 4 D etails about the com petition, the car, and its sign decan be found at http:/ / www. paccar. ethz . ch/ .

F irst, the trade press, engineering journals and chnical te papers presented at engineering society m eetings pr ovide detailed inform ation on the types of technologiesvailable a to im prove fuel econom y and the perform ance, when p- a plied to current vehicles. S econd, m ost of the nologies tech

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

MODELING IMP R OV EMENTS IN V EH ICLE F U EL CONSU MP TION

considered in this report have been introduced in at least a few vehicles sold in the m ark etplace, and actual st te data on fuel econom y can be used.Third, the world’s largest autom anufacturers have research and developm ent staffithw detailed k nowledge of the attributes of each technology, and their inputs in an unconstrained situation can be used to estim ate the beneits of technologies. ( EEA , , 2p.0 90 )7

12 5

autom atic transm ission and a CV T at the sam emtimuste) also be tak en into account. Accounting for Synergies

U ndoubtedly the m ost serious criticism of them P Dethod A is that it does not adeq uately account for synergie s am ong fuel econom y technologies. W hether or not the P D Ach is approa The EP A has provided a sim ilar list of sources nform of i ation. capable of appropriately accounting for synergies is one of the k ey issues addressed by the present com m ittee. These data sources included: vehicle fuel econom yertiic F uel econom y technologies can have both positivedan cation data; peer reviewed or publicly com m ented ports; re negative synergies ( see footnote 1 ) . In addition, he im t pacts peer reviewed technical journal articles and technical papers of technologies applied to vehicle subsystem s could potenavailable in the literature; and conidential data subm issions tially be signiicantly nonlinear, and therefore theeffects of from vehicle m anufacturers and autom otive industry com ponent suppliers. ( EP A , 2 0 0 8 a, p. 2 ) m ultiple technologies m ight not be accurately estim ated by sum m ing the effects of the individual technologies. P ractitioThe EP A considers the vehicle certiication test adatto ners of the P D A m ethod draw on three sourcesorm of infation be an especially reliable source when a directly com parable to estim ate such synergistic effects ( EEA , 2 0 ecause 0 7 ). B vehicle is offered with and without a speciic technology. In m ost of the technologies under consideration are inuse in addition, the NH TS A ’s staff has access to proprieta ry data som e m ass- produced vehicle, it is occasionallyible possto provided by vehicle m anufacturers to directly suppo rt the ind m odels using a com bination of several technolog ies. rulem ak ing process. Com paring the actual fuel consum ption perform ance f these o R ecently, F S S m odels have been ex tensively usedvehicles to to an estim ate based on the sum of their ndividual i estim ate the fuel econom y im pacts of individual hnolotec effects can provide an estim ate of the degree of sy nergy. gies and com binations of technologies ( e. g. , R o,icard Inc. , S econd, sim pliied lum ped param eter m odelseof vehicl 2 0 0 8 a, b; S ierra R esearch, Inc. , 2 0 0 8 ) .byA study done energy use ( e. g. , S ovran and Bohn, 1 9 8 1 ) m provide eans a R icardo, Inc. , for the com m ittee and described ow indibel of avoiding the double counting of energy savings. Given cates that data on technologies’ m ain and synergist ic effects a few k ey param eters, lum ped param eter m odels the allow generated by F S S m odels can be used effectively P D in A q uantiication of sources of energy loss and the components analyses ( R icardo, Inc. , 2 0 0 9 ) . of tractive force req uirem ents for a vehicle. By attributing the im pacts of technologies to speciic energy losses an d tractive force req uirem ents, analysts can check that the seq uential apSequencing Implementation plication of technologies has plausible im pacts on the factors S eq uences for im plem enting fuel econom y technologie s determ ining energy use. A k ey q uestion is whether he uset are usually determ ined by a com bination of costfectiveness ef of a lum ped param eter m odel can suficiently accurat ely acand engineering considerations. A ll else eq ual,would it be count for synergistic effects or whether the F S S thod m m e ust econom ically eficient to im plem ent irst the technol ogy that be used in all cases ( H ancock , 2 0 0 7 ) . A f nthis analysis sub- o offered the greatest reduction in fuel consum ption per dollar ject by R icardo, Inc. ( 2 0 0 9 ) com m issioned by the com m it of cost, followed by the technology with the second largest together with an assessm ent by the EP A considered elow, b ratio, and so on. Engineering considerations m ayctate di a indicates that a reasonably accurate accounting is possible. different seq uence, however. F or ex am ple, V V oth T for b The ability of lum ped param eter m odels to accuratel y intak e and ex haust m ust com e after V V T fornly, intak e predict o vehicle fuel use was irst dem onstrated by S ovran and regardless of cost- effectiveness. Bohn ( 1 9 8 1 ) . In an updated version of the samodology, e m eth F uel consum ption beneits m ust then be converted to S ovran and Blaser ( 2 0 0 3 ) showed that despitechanges m ajor increm ental beneits, given the im plem entation nce. seq ue in autom otive technology, lum ped param eter m till odels s F or ex am ple, the beneit of a 6 - speed transm ust ission be m predicted tractive energy req uirem ents with a high degree of deined as increm ental to that of a 5 - speed transm sion,is accuracy. D evelopm ent of a lum ped param eter egins m odel b even if the base vehicle has a 4 - speed, assum ing at th the with the fundam ental physics eq uations that determ ne the i 5 - speed will be im plem ented before the 6 -5 Obvious speed. energy req uirem ents of vehicles over ix ed driving ycles, c incom patibilities ( e. g. , a vehicle cannot have both a 6 - speed in particular the EP A urban and highway cycles ( ations eq u of the lum ped param eter m odel are presented in Chapter 2 ) . A ny cycle can be divided into three regim es: 5 In

the P D A m ethod a leap from a 4 - speed on transm directly issito a 6 - speed transm ission would be calculated by comngbini the increm ental costs and fuel consum ption effects of the 4 - topeed 5 - stransition and the 5 - to 6 - speed transition.

1 . Tim es when tractive forceTR() Fis req uired from engine;

the

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ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

2. Tim es when deceleration force is greater than rolli ng resistance ( R ) and aerodynam ic drag ( D ) ; and 3 . Tim es when no tractive force is req uired ( le vehic stationary or undergoing deceleration provided by R +D ) .

lows and tractive req uirem ents be m aintained. ch, A sitsu is a powerful tool for q uantifying synergistic effectsor f use in the P D A m ethod. The lum ped param eter m ethod- cannot, how ever, predict the k ind of synergistic effects thatoccur when two or m ore technologies alter each other’s perform ance. W hen tractive force is req uired on either cycle,mit ust This topic is tak en up in detail in the following ection. s eq ual the sum of forces req uired to overcom egrollin resisF S S m odeling m ore com pletely represents such gisticsyner tance, aerodynam ic drag, and inertia. The lum ped rampa eter effects and so it is useful to com pare lum ped param eter and m ethod sim pliies the eq uation for tractive force d other an F S S estim ates to test the adeq uacy of P D Astimsynergy ates. e eq uations for brak ing and idling m odes by integrati ng over The U . S . EP A ( 2 0 0 8 a) used both m ethods the fuel to estim ate the drive cycles, as ex plained in detail in Chapter2 of this econom y beneits of 2 6 technology pack ages applied o ivet report. S ovran and Blaser ( 2 0 0 3 ) found that ped the lum vehicle types. F or m ost pack ages they found close greem a ent param eter m odel deined by Eq uations 2 . 2 and ld 2 . 3 cou between the two types of estim ates ( F igure 8 . 2e EP ). A Th ’s ex plain the tractive energy req uired at the wheels and hence general conclusion was that both m ethods were valua ble and indirectly the engine output of vehicles over either EP A test that the use of lum ped param eter m odeling in P tim D A ation es cycle with an R2 = 0 . 9 9 9 9 . gave reasonable estim ates of synergies. The lum ped param eter m ethod allows changes in pum pBased on this, EP A concludes that the synergies derived from ing losses, engine friction, accessory loads, andther o factors the lum ped param eter approach are generally plausib le ( with to be related in a m anner that can prevent doubleounting c if a few pack ages that garner additional investigation) . ( EP A , done properly. It reduces the lik elihood of overest im ating the 2 0 0 8 b, p. 4 4 ) com bined fuel consum ption im pacts of m ultiple olotechn gies by req uiring that the laws of physics controlling energy

F IGU R E 8 . 2 EP A ’s com parison of full vehicle ion msim odelulat ( R icardo, Inc. ) and lum ped param ) eter P D( LA - Pm odel results. S OU R CE: EP A ( 2 0 0 8 a) , F igure 3 . 3 - 1 .

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In 1 0 cases, signiicant differences were found ( EP, A Determining the “Optimal” Level of Fuel Economy 2008 b) . F or S tandard Car P ack age 1 and S m ck all -M P V P a Calculation of fuel econom y potential and its cost can be age 1 , the lum ped param eter m ethod estim ated er fuel a larg accom plished by algorithm s that decide which techno logies econom y im provem The ent. difference was traced to the to apply and in what order, or by the use of fuel econom y CV T com ponent. The R icardo, Inc. , F S S CVation T represent cost curves. The algorithm ic approach relies on pre deined had a lower eficiency than assum ed in the lum pedram pa eter technology im plem entation seq uences ( decision or trees m odel. Two other cases involved turbo- charging with engine pathways) and is the basis of the D epartm ent ofnsTra downsiz ing. The lum ped param eter m odel estim also ate was portation’s V olpe M odel ( V an S chalk wyk et) al. and , 2 0 0 9 m uch higher in the case of L arge Car P ack age volv6 a, in the Energy Inform ation A dm inistration’s NEM S s m odel’ ing continuously variable valve lift. In the case of L arge M anufacturers’ Technology Choice S ubm odule ( D OE/ , EIA Car P ack age 4 , the lum ped param eter m odel estim a ated 2 0 0 7 ) . The decision tree m ethodology is described elow. b large beneit, but in the case of Truck P ack age the 1 0F , S S Cost curves developed by the NR C ( 2 0 0 2 ) CA and F E study m odel produced the higher beneit estim ate. F orpack the in a num ber of other studies have been reviewed inGreene ages including cylinder deactivation and coordinated cam and D eCicco ( 2 0 0 0 ) . phasing ( L arge Car 1 6 , L arge M P V , and Truck e F S S1 2 ) , th m odeling results were consistently higher. F S Sm esti ates A PDA Algorithm: The NHTSA’s Volpe Model were also higher for the cases involving cam less va lve trains ( L arge Car Y 1 , Truck X 1 ) . The EP A vestigating staff is still in The NH TS A ’s V olpe m odel contains a com pliance a- sim ul reasons for the differences but had identiied at least som e tion algorithm that sim ulates the response of m acturers anuf cases in which the com parison between the two m etho ds led to various form s of fuel econom y standards. D eata putarinto to the discovery of inadvertent errors in the F S Sodeling. m the m odel describing a “CA F E scenario, ” a comonbinati of F or ex am ple, EP A judged that R icardo’s m cylodeling of deinitions of vehicles included in the program , dei nitions inder deactivation and coupled cam phasing was inco rrect of vehicle classes, levels of fuel econom y standard s that because it did not account for cylinder deactivation’s effect m ust be m et each year, and the structure of thendards. sta of approx im ately doubling brak e m ean effectivesure pres The structure com prises several elem ents, the mm athe atical ( BM EP ) in the iring cylinders. The EP A staff tedsugges that form ulation ( e. g. , sales- weighted harm onic mheean) , t conducting both F S S and lum ped param eter analysis as a w functional form ( e. g. , footprint m etric function) the classes , wise strategy since the discrepancies between the two m ethof vehicles to which it applies ( e. g. , foreign orom d estic ods had led to the discovery of correctable errors. m anufacture) , and provisions for trading creditserovtim e Twenty- three of the 2 6 pack ages evaluated by R oicard and am ong irm s. In the description below, the focus is the were also estim ated by EEA , Inc. ( D uleep, 2 com 0 0 8- ) for determ ination of a m anufacturer’s “optim al” fuel onom ec y parison. EEA was not able to estim ate the pack includages level for a given CA F E scenario. ing hom ogeneous charge com pression ignition ( H due CCI) The algorithm begins with a list of vehicles ex pect ed to to the novelty of the technology. The F S S m ethod q uires re be available during the future period being evaluated. This an ex ternally provided representation of the physics of a is typically a narrow window of three to ive m odelyears, device in order to estim ate its im pact on fuel cons um ption. beginning 2 years in the future. V ehicles are disti nguished W hile the F S S m ethod itself cannot characteriz physics e the by m ak e, m odel, engine, and transm ission, EP as in A thetest of technologies, it can produce im pact estim ates vengisuch car list. M any other vehicle attributes are in the vehicles data characteriz ations. The P D A m ethod, on the other d, m han ust base, including sales volum es, prices, and speciications. The be given estim ates of im pacts for novel technologie s. In 1 6 com pliance algorithm applies technologies to each ehicle v of the 2 3 com parisons the two m ethods produced m esti ates in the database individually. In the past, the technologies with relative differences of less than 5 percent. nItwo cases were largely tak en from the NR C 2 0 0 2 report’s tech-three involving CV T transm issions the R icardo estim ate was m uch nology path lists, but for the 2 0 1 1 F uel Econom le, the yR u lower. In the com m ittee’s discussions with R icardo and EEA , NH TS A developed a new technology list with thestance assi it was determ ined that this was due to R icardo’stim es ated of R icardo, Inc. The new list adds diesel and hybr id power eficiency of the CV T being m uch lower than EEA his ’s.inT trains ( including plug- in hybrids) and m aterials bstitution su stance illustrates how both m ethods depend on assum ptions to reduce vehicle weight. It represents other technologies at about the perform ance of k ey technologies. In the emr aining a greater level of detail. It also provides a tableof estim ated ive cases, R icardo’s F S S estim ates were higher therebut appair- wise synergies between technologies. H owever, the peared to be no com m on technology that could exn plai the synergies used in the inal rule appear to be the sam e for differences. One of these cases was again the Truck P ack all vehicles classes. The analysis done for the comm ittee by age 1 0 involving a turbo- charged gasoline directjection in R icardo, Inc. , described below, indicates that syne rgy effects engine: EEA ’s lum ped param eter P D A m ethod a estim ated can vary across applications to different classes of vehicles fuel econom y beneit of 2 6 . 4 percent, whereascardo the R i ( R icardo, Inc. , 2 0 0 9 ) . estim ate was 4 2 percent.

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The algorithm evaluates the applicability of eachecht The algorithm then begins an iterative process of eterd nology to each individual vehicle based on tim ingfoavailm ining a m anufacturer’s com pliance with the CAan-F E st ability and whether or not it is included in decision trees dards. If a m anufacture is not in com pliance, lgorithm the a for that vehicle class. The V olpe m odel’s decision trees are selects the nex t- best technology to add to the vehi cle.6 A analogous to the 2 0 0 2 NR C study’s “paths” exatcept there th technology is selected from the nex t steps on each of the are separate decision trees for internal com bustionengines, applicable decision trees. The single technology that has transm issions, electrical accessories, m aterialstitution, sub the lowest “effective cost” is chosen for im plem ation. ent dynam ic load reduction, aerodynam ic drag reduction, and Effective cost is deined as the total retail price eq uivalent hybrid electric technology. The engine technology decision ( R P E) cost of im plem enting the technology (ge theinchan tree is shown in F igure 8 . 3 . A fter low- friction ricants luband R P E tim es the num ber of vehicles affected) ,y plus change an engine friction reduction are accom plished, the tre e splits in the m anufacturer’s potential CA F E ine, m inus totalthe into three paths depending on cam shaft coniguration . This discounted value of fuel saved by the increase in fuel econallows the NH TS A to tailor the technology seq uencin g to the om y, all divided by the num ber of vehicles affected . F ines base vehicle’s engine attributes. If fuel econom sy pushed i to are calculated so as to tak e account of credits forex ceeding higher levels the three paths then converge on the stoichiostandards on som e vehicles that can be transferredto other m etric, gasoline direct- injection engine. A table f notes o can vehicles. S om e m anufacturers are assum ed not willing to be be used to “override” the algorithm ’s logic and det erm ine to pay ines and so for them that option is rem oved. The curapplicability in special cases ( e. g. , as in Table, 4D OT, 2 0 0 5 rent ) . version of the m odel calculates credits or dei cits ( negaIn the com m ittee’s judgm ent, it is not necessary haveto tive credits) generated by ex ceeding or failing tom eet the separate decision trees for engines and transm issio ns. This standard in any given year. It does not, however, ttem a pt to view is supported by the R icardo, Inc. ( 2 0 0 9 sis, ) analym odel credit trading either within a m anufacturer verotim e which dem onstrates that the im portant across, or ter-in or am ong m anufacturers. The algorithm continues sidercon decision- tree, synergies are between engines and tr ansm ising and im plem enting nex t- best technologies for vehicle all sions ( R icardo, Inc. , 2 0 0 9 ) . These inter-gies treecan syner classes until a m anufacturer either achieves com ance pli with be transform ed to increm ental im provem ents byning com bi the standard, ex hausts all available technologies,or inds engines and transm issions into a single power train decision that paying ines is m ore cost- effective than increa sing fuel tree. Once this has been done, nearly all im portant synergies econom y ( V an S chalk wyk et al. , 2 0 0 9 , p. 2 ) . can be addressed by adjusting technology im pacts to account In a joint EP A and NH TS A ( 2 0 0 9 ) notice of propose for interactions with technologies previously im plem ented in rulem ak ing ( NP R M ) the EP A introduced its on optim iz ati the decision tree, or pathway. m odel for reducing em issions of greenhouse gasesomfr In the V olpe m odel, the cost and fuel econom y tim pac auto m obiles ( OM EGA ) m odel. L ik e the V olpe m od of each technology vary by vehicle class. P reviousl y the OM EGA is based on the P D A m ethod and although ogic the l 1 0 vehicle classes of the 2 0 0 2 NR C report were , butused of the two m odels is fundam entally the sam e, are there som e the 2 0 1 1 rule is based on 1 2 vehicle classes nclude that i4 notable differences. The V olpe m odel operates on dividual in perform ance- based classes: vehicle conigurations ( on the order of 1 , 0 0 0 m m ak odel, e, engine, and transm ission com binations) , tak ing account into 1 . S m all light truck ( including S U V s and pick ups) the ex , isting or planned use of fuel econom y technol ogies 2 . M idsiz e light truck ( including S U V s )and , pick on ups each one. The OM EGA m odel deals with approxly im ate 3 . L arge light truck ( including S U V s andand pick ups 2 0 0 vehicle platform s brok en down by engine P sizAe ( and E full- siz e vans) , NH TS A , 2 0 0 9 ) . F or the purpose of estimogy ating technol 4 . M inivans, im pacts the 2 0 0 + platform s are divided intocle1 types 9 vehi 5 . S ubcom pact cars, that attem pt to distinguish am ong power trains and m ark et 6 . S ubcom pact perform ance cars, intent. Each of the 1 9 vehicle types are groupedtoinive 7 . Com pact cars, vehicle classes ( sm all car, large car, m inivan,ll truck sm a , 8 . Com pact perform ance cars, and large truck ) for the purpose of scaling cost es tim ates. In 9 . M idsiz e cars, general, the EP A ’s baseline vehicle is deined ase on with a 1 0 . M idsiz e perform ance cars, port- fuel- injected, naturally aspirated gasoline en gine with 1 1 . L arge cars, and two intak e and two ex haust valves and ix ed valve m ti ing and 1 2 . L arge perform ance cars. lift, and a 4 - speed autom atic transm ission. FNHor the TS A ’s V olpe m odel the baseline is the actual coniguration of each The seq uence in which the technologies are appliedto any given vehicle is determ ined by an optim iz ation algo6 The V olpe m odel allows m anufacturers to opt for n- com no pliance if rithm . Technologies already in use in a given vehic le are paying a ine is less costly than m issing the standa rds, and if a switch set in “carried over” from the previous year so that theyare not input data iles allows such non- com pliance. Thistion op is not discussed duplicated. here for the sak e of brevity.

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F IGU R E 8 . 3 V olpe m odel engine technology ree. decision t

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−1 vehicle coniguration as it ex ists or is predicted ot ex ist in   the baseline leet. −1 nj  Nk s     The V olpe m odel applies individual technologies one at a  ∑ j  MPG  1 + ∑ ∆    Eq uation 1 j ij tim e in a seq uential algorithm , whereas the OM odel EGA m   j =1 N k   i= 1      ∑ sj  applies predeined pack ages of technologies that hav e been   j =1 rank ed by cost- effectiveness for each vehicle type. H owever, the pack ages are assem bled from individual technolo gy im If the calculation is done in term s of fuel consumtion, p pact estim ates, with synergies between technologies within a or gallons per m ile ( GP M ) , the correspondingoneqforuati pack age incorporated in the technology pack age imct pa estiollowing: f m ates. The EP A used the lum ped param eter mdeterethod to the m anufacturer’s fuel consum ption target is the m ine the adjustm ent factors ( EP A and D OT,1 27 01 0) 9. , p. nj Nk Because neither the V olpe CA F E Com pliance and ctsEffe  sj  Eq uation 2 M odeling S ystem nor the EP A ’s OM EGA m of odel m ak e use ∑ N k GPM j ∏ 1 − δ ij  j =1 i− 1   cost curves but rather em ploy com puter algorithm neither s, sj ∑ j=a NH TS A nor EP A req uire cost curves but rather of fuel a list econom y technologies including cost, applicability, and Eq uations 1 and 2 m ak e two strong assum ptions. t, F irs synergy estim ates. This com m ittee’s m ethod isonbased they assum e that the relative fuel consum ption im ct ofpaa im plem entation pathways that are analogous to the olpe V B m odel’s decision trees and the OM EGA m odel’ses. pack agtechnology will not vary from vehicle to vehicle. ecause im pacts will vary depending on the initial design foeach Therefore, this com m ittee determ ined that it was t necesno vehicle, som e error will be introduced for each veh icle. sary for this study to produce cost curves as such. In addition, it is assum ed that, for a given im entation plem seq uence, any interactions ( synergies) am ong techno loAggregating to Estimate Manufacturers’ Fleet Average gies have already been accounted for in the ∆ or δ term s. Fuel Economy Given inform ation on technology synergies generatedby F S S m odels, eq uations 1 or 2 could be m nclude odiied to i Because fuel econom y standards are enforced on auto m obile m anufacturers, both the F S S and P D A msynergistic ethods effects as each technology is added. S mu m ing relative fuel econom y increases as in eq uation 1oduces pr req uire a m eans of inferring the fuel econom y poten tial a sm aller estim ate than seq uentially m ultiplying e plus on of an OEM from the fuel econom y potential of dual indivi the relative fuel econom y increases. M ost fuel econ om y vehicles or vehicle classes. The F S S m ethod is ciently sufi im pact estim ates have been determ ined with thectation ex pe com putationally intensive that it has not been prac tical that they will be added to obtain the overall fuel econom y to carry out sim ulations for all thousand or so veh icles in beneit. L ik ewise, m ultiplying the term s in eq2 uation will the EP A test car database for all relevant com ions binatof produce a sm aller estim ated change in fuel consum ption than technologies. U sing the P D A m ethod, a m anufacturer’ s fuel adding the δi, which could erroneously lead to negative fuel econom y potential can be calculated using data onndividual i y im or conigurations ( m ak e, m odel, engine, transm . e. ission, , a i consum ption. In either case, adding fuel econom pacts m ultiplying fuel consum ption im pacts is intended produce to single entry in the test car database) or using data on classes that r the of vehicles. The NH TS A ’s V olpe m odel, for calcuex am ple,an approx im ation to the true im pact in a way educes chances of overestim ating fuel consum ption beneits. lates a m anufacturer’s fuel econom y target usingdividual in vehicle data since each vehicle has its own fuel econom y target as a function of its footprint. The m odelso al calculates Aggregation over Vehicles in a Class each m anufacturer’s fuel econom y potential at the test car list The P D A m ethod can be applied to an individual clevehi level of detail. Estim ates based on vehicle classes can also or to a representative vehicle ( e. g. , a m idsiz senger e pas car) . be com puted but they will only be approx im atelyaleqto u F or an individual vehicle, it is necessary to k now the ex isting estim ates based on individual conigurations. technology m ak eup of the vehicle so that incom ilities patib A ssum e that the optim al level of fuel econom single y for a are avoided and technologies are not applied twice. In the vehicle coniguration j has been determ ined to include technologies k = 1 to nj ( given a technology im plem entation se- case of a representative vehicle, it is necessary to k now the m ark et shares of fuel econom y technologies forcles vehiin q uence and fuel econom y im pacts adjusted for imentation plem its class. In general, the ex act distribution of lalcom binaorder and synergies) . The cum ulative fuel economm y pact i is calculated by sum m ing the fractional fuel econom y ( m iles tions of technologies within the vehicle class is not k nown. Instead, the total m ark et shares of each technology are used, per gallon) im provem ents, adding one, and m ng ultiplyi by the in effect assum ing that their distributions are ind ependent. base fuel econom y M 0jP. IfG the sales of vehicle coniguraThis introduces a further elem ent of approx im ation into the tion j are sj, then the fuel econom y for m anufacturer k selling estim ation. conigurations j = 1 N tok is the following:

(

)

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13 1

the vehicle ( m ass, frontal area, drag coeficient, tc. )e , the L etsij, 0 be the initial m ark et share of technology i in the com ponents that com pose the driveline ( engine and rans-t vehicle class j, and let sij, m axbe the m ax im um m ark et share s, etc. ) , for technology i. The estim ated change in fuel econom y m ission, etc. ) , accessories ( pum ps, fans, generator and a speciication of the drive cycle, or vehicle speed trace, ( M P G) by application of the full set of technologie s is given the vehicle is to perform . Com ponents are represent ed by by eq uation 3 : nj com puter m odules and m ay be described by perform e anc m aps represented by tables or eq uations. A ll energy lows D j max = ∑ sij ,max − sij ,0 ∆ ij Eq uation 3 i =1 am ong com ponents are accounted for by eq uations k lin ing the m odules. F S S m odels m ay be back wardor look ing The estim ated change in fuel consum ption by applica tion forward- look ing. Back ward- look ing m odels assum t e tha of the full set of technologies is given by eq uation 4 : the drive cycle’s velocity and acceleration trajectory will be m et, calculate the force req uired at the wheels, and then  nj  work back ward to the resulting engine speed, and eth necesEq uation 4 d j max = GPM  ∏ 1 − sij ,max − sij ,0 δ ij    i =1 sary throttle and brak e com m ands. F orward- look odels ing m choose throttle and brak e com m ands in order toeve achithe The cost of the above fuel econom y increase is calc ulated speciied trace. S om e m odels use a com binationth of bo sim ilarly, where Ci is the cost of technology i in retail price strategies ( see, e. g. , M ark el et al. , 2 0 0 2 ) . eq uivalent: M odeling can have the potential beneit of helpingne o to nj understand these synergies and better predict future perforC j max = ∏ sij ,max − sij ,0 Cij Eq uation 5 m ance, either through the careful analysis of avail able vehii =1 cle data, or through creating dynam ic m odels ofvehicles the and analyz ing the perform ance of these virtual vehi cles. In A lthough eq uation 3 approx im ates the share- weighted addition to the synergies within various subsystem of s the harm onic m ean change in fuel econom y for a class ve-of vehicle, m any subsystem s within the vehicle ex nonhibit hicles with a m ix ture of technologies it does notrecisely p linear behavior. Considering the perform ance of ind ividual eq ual it. Even perform ing the calculations in term of fuel s subsystem s independently, even if this perform ance is well consum ption, as in eq uation 4 , will not produceextheact k nown and understood, can therefore result in m ading isle harm onic m ean fuel econom y, in general. conclusions for the overall system . W hen an underst anding of each subsystem can be represented by a com puter m odel MODELING USING FULL SYSTEM SIMULATION to an appropriate level of detail, and the interconnectivity or physical com m unication between each of these subsys tem s The F S S approach to m odeling vehicle fuel consum pcan also be adeq uately represented, the synergistic and nontion involves capturing the physics or characteristics of linear effects can be included and analyz ed in thebehavior subsystem s of the vehicle in software, assem bling these subof the entire system . Com puter m odeling of vehicle system s system s by passing relevant operational variables etween b these subsystem s, and choosing preferred input variables and is widely used in the industry for this purpose, as well as nder u trajectories to sim ulate desired vehicle operation. The overall to help predict future perform ance or perform ance various conditions. M anufacturers use F S S inoduct the pr goal is to have the subsystem m odels work in a rgistic syne developm ent process to optim iz e factors such as ft shi logic way to relect the actual perform ance of the vehicle in variand inal drive ratio. ous m aneuvers. Because of the com plex ity and nonlin earity F or new technologies not im plem ented in any m assof these vehicle subsystem s, it is often dificult o anticipate t produced vehicle, F S S m odel results are probably e m thost the synergistic effects, especially during transients, and this reliable source of estim ates of synergistic effects . H isapproach usually provides this useful inform ationot som e been for degree of accuracy. F S S m odeling has been used heby t torically, the P D A approach has generally not used estim ating the fuel consum ption im pacts of novel hicle ve autom otive industry since the 1 9 7 0 s, and isena m provethod system s for which there are no actual test data ( eene Gr and of estim ating the im pacts of ex isting and new techn ologies 2 0 0 0 ) . Today F S S m odeling is sed m ore widely u on vehicle system s ( W aters, 1 9 7 2 ; Blum M berg,ore1 9 D 7 6eCicco, ). to estim ate the potential for reducing fuel consumtion p than recently, regulatory agencies and other groups outside the even 5 years ago. A num ber of studies are available that autom otive industry are undertak ing efforts to deve lop and used F S S to estim ate the fuel consum ption cts im of pa utiliz e F S S in their analysis ( NES CCA F , 2 eau, 0 0 4 ; have R ouss advanced technologies ( e. g. , R icardo, Inc. , 2 , 0 20 08 0a,9b ; 2 0 0 7 ; EP A , 2 0 0 8 a) . A lthough m odeling approaches differ, all F S S are m odelsK asseris and H eywood, 2 0 0 7 ; K rom er and H7 ;eywood, 2 0 S ierra R esearch, 2 0 0 8 ) . It should be noted,, that however based on the tim e integration of Newton’s second w la ( i. e. , inF = ⋅a) m over som e driving m aneuver, in this case over e th suficient k nowledge of the technology pack age being vestigated is necessary to allow its representation within the F TP and highway driving cycles. The boundary anditial in m odel to have an acceptable degree of accuracy. F anoragconditions for this integration are based on a description of

(

)

) )

( (

(

)

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13 2

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

gregate technology, this m ay tak e the form ofform a per ance U nfortunately, data on the predictive accuracy ofSF S m ap describing its eficiency over a range of operating condim odels are scarce. In part this is because som e m els od tions. F or a technology described by uniq ue operati on of an and m ore often the representation of their com ponen ts are ex isting subcom ponent, relevant perform ance insight in the proprietary to irm s that use them in their own rese arch or corresponding new regim e of operation would be nece ssary. consulting. The com m ittee is not aware of any rigor ous study It is im portant to note that, although F S S m ave odels h evaluating the accuracy of m odels for various appli cations. the ability to estim ate the absolute im pacts of icle veh The few com parisons the com m ittee has seen indicate that technologies due to their ability to m odel the phys ics of for k nown vehicles, sim ulation m odels can reproduce fuel system com ponents, they have lim ited ability toel m the od consum ption and perform ance with a high degree of ccua dynam ic work ing of individual fuel eficiency techno logies racy. D ata provided by R icardo, Inc. , based on research its and generally rely on a lim ited set of input data.F or novel for the EP A indicated a range of error in predictin g fuel technologies, m any of the input param eters are m assuptions consum ption of 1 to 3 percent for ive vehicles ure ( F 8ig. 4 ) . based on engineering judgm ent and ex perience with elated r F or this m odeling, the EP A chose a speciic represen tative technologies. This em phasiz es the fact stated at the outset vehicle for each of the ive classes: the Toyota Camry for the of this chapter, that one cannot k now with absolute ly acstandard car, the S aturn V ue for the sm all M Chrysler P V , the curacy the im pact of technologies until an actualehicle v is 3 0 0 for the full- siz e car, the D odge Grand Caravan for the constructed and repeatedly tested. large M P V , and the F ord F 1 5 0 for the truck , Inc. . R , icardo ( 2 0 0 8 a) attributed any discrepancies between mtheulasi tion results and the actual vehicle data to the use of generic Model Fidelity input data for that vehicle class instead of actual data for a A n im portant consideration for F S S m odeling dingis deci speciic vehicle. Of course, these are k nown vehicle s so that what level of idelity of the eq uations or look - up ables t is com ponent representations and the overall m odel can be req uired for the problem being addressed. No seteq of uacalibrated. P rediction errors for truly novel techn ologies for tions com pletely relects the detailed physics of th e actual which no vehicle ex ists to calibrate to would presum ably be process, so the choice of idelity should be a conscious choice larger. In any event, it is the change in fuel consum ption from from a continuum of m odels of varying idelity, of which all the im plem entation of a technology that is of minterest. ost represent sim pliications of the actual process. The objective The absolute error of a predicted change can be sm aller when is to achieve an appropriate balance of idelity with m odeling prediction errors sim ilarly ex ist in both the “befo re” and goals, m odeling effort and resources, sim ulation eed,sp and “after” sim ulations ( i. e. , the m odeling errors he of before t available data that speciically characteriz es the ys stem being and after cases are strongly correlated) . S till,lative re errors m odeled. There is always a difference between theims ulafor a predicted change are lik ely to be greater. Th e accuracy tion and actual subsystem operation, k nown as the odeling m of F S S m odels in predicting fuel consum ptionschange in error. The tolerable level of error depends upon the goals of actual vehicles deserves additional study. Note that such an the sim ulation. accuracy study is m ade m ore dificult by the factat ththe

F IGU R E 8 . 4 Com parison of actual vehicle com el econom bined fu ies and R icardo sim ulated fuel economor ive ies fvehicles. S OU R CE: R icardo, Inc. ( 2 0 0 8 a) .

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

MODELING IMP R OV EMENTS IN V EH ICLE F U EL CONSU MP TION

13 3

accuracy of F S S estim ations depends signiicantly theon tions. One set of data can be used to determ ine par am eters ex perience and sk ill of the F S S practitioner. or tune the subsystem m odels, and a separate and stinct di The lex ibility, rigor, and com prehensiveness ofFtheS S set of data can be used to test the predictive capabilities of approach to vehicle m odeling are signiicant advanta ges. the m odel in different situations after it has beentuned or S ubsystem m odels m ay be as sim ple as a single eterparam calibrated. The m odel should not be tested using ethsam e or table based on steady- state operation, or a deta iled, nonset of data that was used to calibrate the m odel. linear, m ultivariable representation of the dynams of ic the subsystem , including transient operation. The choic e of FSS Model Example how to represent each subsystem m odel is not only ased b on m odeling error considerations discussed above,utb also A n ex am ple of an F S S com pression- engine m odel is on balancing idelity between subsystem m odels, rder in o to illustrated in F igure 8 . 5 in order to give the er read a better use com putational resources as effectively as possi ble. One visual idea of a possible subdivision of subsystem within s way of look ing at balancing idelity between subsystem s the overall system m odel, as well as possible choic es of is to consider the iltering properties or bandwidth of these idelity within each subsystem . The overall goal this of m odel subsystem s. If one subsystem m odel has a level delity of i is to represent engine transient perform ance withinthe vethat generates details in an output variable that are iltered hicle power train, including cylinder- by- cylinderotational r out by a subseq uent system , then the effort in gene rating dynam ic effects as well as irst order intak e and haust ex those details is m ostly wasted if the interm ediate variables dynam ics that affect turbocharger transient effectson the between the subsystem s are not of interest. This lance ba of engine. S om e sim ple em ission transient predictive apabil-c idelity within an overall F S S m odel is a judgmall ent thatc ity is included but is not com prehensive for all co nstituents. is typically developed through ex perience or trialand error, This m odel was developed using the M A TL A B/ S im ulink although the effects can be clearly seen by look ingcarem odeling software, and its overall structure is pre sented by fully at the content of the variables that are passed between the block diagram structure of M A TL A B/ S ierim ulink in h subsystem s to see what effects are preserved or eli m inated. archical form . M ost of the subsystem m odelsntiied are ide A n ex am ple of these considerations can be seen xby- e for the reader. The core of the m odel is the engine m ap that am ining a typical system m odel of a turbocharger. n m Iany provides brak e- speciic fuel consum ption as a function of endynam ic system m odels, the characteristics of the both gine speed and load. Num erous other m odules areessary nec turbocharger com pressor and turbine are sim ulated ased b to represent the m any interacting com ponents of engine the on steady- state m aps. H owever, the rotational dynam ics system . M ost of these com ponents m ust be calibrated to the of the rotor is sim ulated based on Newton’s secondlaw speciic engine system of interest. ( i. e. , a differential eq uation relecting dynam transient ic or operation) . The rationale for choosing and com binin g these AN ANALYSIS OF SYNERGISTIC EFFECTS AMONG two different types of m odels is based on the ideathat the TECHNOLOGIES USING FULL SYSTEM SIMULATION tim e constants for the gas dynam ics in the com or press and turbine are considerably shorter ( i. e. , faster) ntha the tim e A t the req uest of the com m ittee, R icardo, 9Inc. ) (2 0 0 constant of the rotor. If m uch m ore detailed dynam c m odels i undertook a study to q uantify the synergistic effec ts captured of the gas dynam ics were included in the m odel when the by F S S m odels. It is im portant to note that dythe is based stu rotational speed of the rotor is the desired output variable, solely on the predictions of R icardo, Inc. ’s F S dels S mando alm ost all of the gas dynam ic effects would be ilte red out therefore can q uantify only the synergies those m els od can by the rotor inertia or rotational bandwidth. This com binarepresent. In its report, R icardo estim ated theuracy acc of its tion of steady- state and dynam ic m odels to represen t the m odels for predicting fuel econom y at 1 percentwellfor turbocharger usually provides an effective dynam icm odel characteriz ed vehicle system s ( system s for which arlyneall of its rotational dynam ics and transient operation in relation m odel subsystem s have been calibrated to the actual com to the rest of the engine. H owever, if the goal to is capture ponents) and 3 percent for novel vehicle system s. owever, H the pulsed gas dynam ics in the turbine or com presso r, this each estim ate of accuracy was based on a single dat a point choice of subsystem m odels m ay not be appropriate for ( and so cannot be considered deinitive. that speciic goal) . The im portant point is that m e detail or R icardo’s approach was to sim ulate the technologies is not necessarily better, but idelity and balance should be contained in ive different pack ages of technologiesit had conscious decisions relecting m odeling goals. previously m odeled for the EP A ( 2 0 0 8 a) as o ive applied t different types of vehicles. The technologies were applied one at a tim e and in com binations according to gorously a ri Model Validation deined design of ex perim ents. The results were then itted by A n effective way of carrying out m odel validation, given a response surface m odel using a neural network m hod.et The available data on the system operation, is to subdi vide the response surface m odel it the data with m ax im ors umof 1err data into at least two sets covering different operating condipercent using term s no higher than second order ( gure F i8 .6 ) .

Controller

cont

mdot_fuel CA_inj

Product

x dot_v eh

Engine Load Torque

Engine eng pow er

Air Filter

flow_comp_out

mdot_table

Conditions

D riv eline and Ambient v ehicle dy namics1 Atmospheric

feedgas

pressures

Intercooler

flow_filt_out

fresh air mass

Selector

fuel kg/cycle

3

airflow To Workspace

state_intake_man

T_wall 6 Cylinder Engine Manifolds

flow_em_out

flow_im_in

state_man

Turbocharger

mair Goto

3

Goto1

rpmeng

Intake Manifold Heat flow

0

mdot_im_in Hdot_im_in phi_im_in

q

state_exhaust_man

P_cyls

2

torq_inds

Phased CAs RPMs

Backpressure 2 Atmospheric Conditions

flow_turb_in

CAs

3

Mux1

Mux

flow_im_in

Intake Manifold

Single Inlet Manifold

state_im

flow_intake_manifold_out

T_exh exhaust flow_im_out co,nox m_exh

Mux

exh temp

T_wall

5

fuel kg/cycle CA_inj

2

CAs RPMs

1

1 N_eng

4 torq_load Rigid Crankshaft

flow_turb_out

P_im T_im phi_im

3

6 Cylinders

torq_cyls

1

P_cyls

2

Q_cyls

torq_cyls1

5

flow_exhaust_manifold_in

flow_em_out

4

state_cylinders

Exhaust manifold

flow_em_in

exhaust composition

6

state_exhaust_manifold

4

state_em

Outlet manifold state calculations

Crank angle-varying inertia calculations

Crankshaft dynamic calculations

Rotor torque and flow calculations

Compressor and turbine data

Turbocharger speed calculations

Dynamic driveline model

After treatment system module

F IGU R E 8 . 5 A n ex am ple structure for aim full system ulation diesel s engine dynam ic m odel. OU SR CE: R eprinted with perm ission from J ohn a, J .PMowertrain osk w Control R esearch L aboratory, U niversity of W isconsin, M adison, W isc.

EGR

Cushioning Manifold

flow_comp_in

After treatment system

0

Intake manifold state calculations

EGR calculations

Intercooler flow and efficiency calculations

Manifold pressure calculations

Air filter flow and pressure drop calculations

starting simulation

double-click before

time

Backpressure Reservoir Conditions

Crankshaft speed

rpm_av g

Engine module

13 4

Load V ehicle S pecific D ata

Clock

0

Ambient Conditions

P ow ertrain S y stem S imulation w ith Cy linder -by -Cy linder M odel Copy right ( c) 1 9 9 9 , All R ights R eserv ed

P ow ertrain Control R esearch Laboratory The U niv ersity of W isconsin -M adison

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

MODELING IMP R OV EMENTS IN V EH ICLE F U EL CONSU MP TION

13 5

fact that when technologies are applied in seq uencethe fuel consum ption im pact of a technology depends on which technologies have been previously applied. F or ex am given ple, a base vehicle with a 4 - speed transm ission, theact im ofpa 6 - speed transm ission will be sm aller if a 5 -ransm speed tission has been previously applied. The P D A m ethod plicitly ex recogniz es this k ind of interaction by ordering tec hnologies for interaction and using only increm ental im pacts, given that ordering, to estim ate the total fuel consum onpti im pact. But increm ental effects, as deined in the R icardo NOV A A , also include true synergistic effects, such as whena 4 2 - volt electrical system is im plem ented together withtric elec accessories ( e. g. , electric power steering) . M ost m P D odelA ers attem pt to tak e such interactions into account, but the F IGU R E 8 . 6 R icardo, Inc. , statistical ( response face m odel sur accuracy with which they do so will depend on the available [ R S M ] ) predictions versus full system sim del ulation predicm o data sources and the engineering judgm ent of the an alyst. tions. SOU R CE: R icardo, Inc. ( 2 0 0 9 ) , F igure 3 - 2 . There are additional synergies of interest that R ic ardo term s “inter- tree” or “true” synergies. These are he tinteractions am ong technologies that are neither second- der or m ain effects nor increm ental effects. P D A m odeling t, in canno This shows that a relatively sim ple 2 nd order regre ssion general, account for this type of synergy. A ccordin g to the m odel provides a very suitable representation of th e m ore results of R icardo’s study, these effects are q uite sm all. F or com plex vehicle sim ulation output with m ax im um R S M ex am ple, adding up the synergy ( intertree) effects for S m all ( R esponse S urface M odel, ed. ) residual errors outof ab M P V P ack age 5 ( allowing positive and negative ts to effec 1 percent, or that higher order effects ( 3 rd order and above) cancel) results in a total synergy effect of −1 . 3 ercent p of account for less than 1 percent of the vehicle simlation u the total fuel econom y im pact of the technology k pac age. output characteristics. ( R icardo, Inc. , 2 0 0 ) 9 , p. 1 3 A dding up the inter- tree synergies produces a posit ive synergy of 4 . 6 percent for S m all M P V P ack itive age 1 5 , a pos This inding is signiicant in that it indicates that im portant synergy of 2 . 8 percent for L arge M P V P ack d age a 1 6 , an synergistic effects ( as represented by the F S S m ls) ode are of positive synergy of 1 0 . 3 percent of the total fuel econom y no higher order than two- way interactions. It is al so generim pact for Truck P ack age 1 1 . These are percentages of the ally consistent with the ability of a m uch sim pler lum ped s due to param eter m odel to accurately estim ate fuel econom over y total fuel econom y change and so suggest that error com pletely ignoring intertree synergies are on the order of the federal test cycles with S ovran and Blaser ( 2 60 ) 0. 1 0 percent or less for the total fuel econom y im t. The pac siz e The nex t step was to carry out an analysis of variance of these effects is roughly consistent with the discrepancies ( A NOV A ) to q uantify the irst- order ( m ain) d- order and secon effects. The A NOV A estim ated that m ain effects ech- of t EP A ( 2 0 0 8 b) found in its com parison of lumeterped param and F S S m odeling. nologies accounted for 8 0 to 8 6 percent of theeconom fuel y R icardo, Inc. ( 2 0 0 9 ) concluded that P D Auchm odeling, s increase. Interaction effects, tak en together, acco unted for as that used in the NH TS A ’s V olpe m odel, ifd inform by e 1 4 to 2 0 percent. R icardo, Inc. , concluded pliied that sim rigorously designed F S S m odeling of the k ind ented repres in m odels that did not properly account for interactio n effects its study, can produce accurate estim ates of fuel consum ption could have estim ation errors of up to 2 0 percent. owever, H 2 0 reduction potential. This conclusion, however, isonditional c percent not only is the upper bound on estim ationrror e but on the accuracy of F S S m odels for predicting EP st cycle A te also assum es that the error in estim ating interacti on effects fuel econom y. Given the scarcity of evidence on thi s subject is 1 0 0 percent ( for ex am ple, if they were all atedestim to and its im portance to validating R icardo’s conclusi on, it be 0 ) . Interaction effects estim ated using lum aram ped p eter m erits further investigation. m odels, for ex am ple, are lik ely to be m uch sm aller. Even m ore im portantly, the interaction effects ude incl second- order m ain effects and increm ental effects. S econdFINDINGS order m ain effects represent the interaction of aechnology t Finding 8 .1 The : state of the art in estim ating the im pacts of with itself and are introduced to account for nonlinear effects fuel econom y technologies on vehicle fuel consum on ptiis in the linear A NOV A m odel. Thus, they do not on depend full system sim ulation ( F S S ) because it is integrabased on the presence or absence of other technologies and so are tion of the eq uations of m otion for the vehicle ried car out not synergies in the sense that is of interest. Increm ental efover the speed- tim e representation of the appropria te drivfects include som e true synergistic effects and som e purely ing or test cycle. D one well, F S S can provide curate an ac increm ental effects. P urely increm ental effects ectrel the

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

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ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

assessm ent ( within −5 + / percent or less) of the im pacts on fuel consum ption of im plem enting one or m orelogies. techno The validity of F S S m odeling depends on the accurac y of representations of system com ponents ( e. g. , engine m aps) . Ex pert judgm ent is also req uired at m any points g. , (detere. m ining engine warm - up rates or engine control egies) strat and is critical to obtaining accurate results.

dem onstrated a practical m ethod for using data gene rated by F S S m odels to accurately assess the fuel consum n potenptio tials of com binations of doz ens of technologies on thousands of vehicle conigurations. A design- of- ex perim tatistical ents s analysis of F S S m odel runs dem onstrated thatffects m ain ande irst- order interaction effects alone could predictF S S m odel outputs with an R2 of better than 0 . 9 9 . U sing such an approach could appropriately com bine the strengths of bothhet F S S and Finding 8 .2:The partial discrete approx im ation ( P D Athe) P D A m odeling m ethods. H owever, in Chapter com -9 the m ethod relies on other sources of data for estim sate of the m ittee recom m ends an alternate approach that would use F S S im pacts of fuel econom y technologies. U nlik eheFP SDS A, t to better assess the contributory effects of technologies applied m ethod cannot be used to generate estim ates of im the pacts for the reduction of vehicle energy losses and to better couple of individual technologies on vehicle fuel consum pt ion. the m odeling of fuel econom y technologies to the sting te of Thus, the P D A m ethod by itself, unlik e F suitable S S , is not such technologies on production vehicles. for estim ating the im pacts on fuel consum ption echnoloof t gies that have not already been tested in actual vehicles or REFERENCES whose fuel consum ption beneits have not been estimtedaby for theAdesign tool and m eans of F S S . L ik ewise, the effects of technology nterac- i Blum berg, P . N. 1 9 7 6 . P owertrain sim ulation: evaluation of engine control strategies in vehicles, S A E Technical P aper tions m ust be determ ined from ex ternal estimapprox ates oriS eries 7 6 0 1 5 8 . S A E International, W arrendale, ebruary 2 3P .a. F m ated by a m ethod such as lum ped param eter m g. odelin D OE/ EIA ( U . S . D epartm ent of Energy/ Energy on AInform dm inistration) ati . Even F S S , however, depends directly on ex ternally enerated g 2 0 0 7 . Transportation sector m odule of the National Energy M odeling inform ation on the perform ance of individual techno logy S ystem : M odel docum entation 2 0 0 7 , D OE/ EIA ) . Ofice - M of 0 7 0 (2 Integrated A nalysis and F orecasting, W ashington, C. D . com ponents.

0 0 7

D OT ( U . S . D epartm ent of Transportation) . 2 com 0 0 5pliance . CA and F E effects m odeling system . V olpe S ystem s Center, ridge, Cam M bass. , Finding 8 .3 Com : parisons of F S S m odeling and P D A J esuly 1 9 . tim ation ( within the range of cases where the P D ethod A m D OT/ NH TS A ( U . S . D epartm ent of Transportation/ al H ighway Nation is applicable) supported by lum ped param eter m ngodeli to Trafic S afety A dm inistration) . 2 0 0 9 . A conom verage fuel y standards, e passenger cars and light truck s, m odel year 2 0 1 1 : F, R inalIN rule 2 1 2 7 elim inate double counting of energy eficiency im vepro A K - 2 9 , D ock et No. NH TS A 2 0 0 9 - 0 ,0 M6 2arch , W2 3ashington, . D m ents have shown that the two m ethods produce sim ar re-il D uleep, K . G. 2 0 0 8 . EEA - ICF analysis update, ation to the P resent Com m itsults when sim ilar assum ptions are used. In somstances, e in tee on Technologies for Im proving L ight- D uty V e Fehicl uel Econom y, com paring the estim ates m ade by the two m ethods has A pril 1 , W ashington, D . C. enhanced the overall validity of estim ated fuel con sum ption EEA ( Energy and Environm ental A nalysis, Inc. .) .Technologies 2 0 0 7 to im prove light- duty vehicle fuel econom y, D raft rt to repo the National im pacts by uncovering inadvertent errors in one or the other R esearch Council Com m ittee on F uel Econom y-of DL uty ight V ehicles, m ethod. In the com m ittee’s judgm ent both m e ethods valu- ar A rlington, V a. , S eptem ber. able, especially when used together, one providinga check EP A ( U . S . Environm ental P rotection A gency) EP A. 2S0 taff 0 8Technia. on the other. H owever, m ore work needs to be done o es- t cal R eport: Cost and Effectiveness Estim ates of Tec hnologies U sed tablish the accuracy of both m ethods relative to ac tual m otor to R educe L ight- D uty V ehicle Carbon D iox ide ns.Em EP issio A 4 2 0 R - 0 8 - 0 0 8 , A nn A rbor, M ich. vehicles. In particular, the accuracy of applying lcass- speciic EP A . 2 0 0 8 b. EP A ’s technical review of Rations, icardoPsim resentation ul to estim ates of fuel consum ption im pacts to individual vehicle the Com m ittee on Technologies for Im proving L uty ightV Dehicle F uel conigurations needs to be investigated. The m agnitu de of the Econom y, M arch 3 1 , 2 0 0 8 , D etroit, M ich. errors produced when such estim ates are aggregatedto calEP A and D OT ( U . S . Environm ental P rotection nd UA . S gency . D a epartm ent culate the potential of individual autom obile m facturers anu of Transportation) . 2 0 0 9 . P roposed R ulem tablish ak ingLtoightEs D uty V ehicle Greenhouse Gas Em ission S tandards and Corpo rate A verage to reduce fuel consum ption should also be analyz ed. F uel Econom y S tandards. A ugust 2 4 . W ashington, D . C. EP A and NH TS A ( U . S . Environm ental P rotection and National A gency Finding 8 .4 The : U . S . D epartm ent of Transportation’s V olpeH ighway Trafic S afety A dm inistration) . 2 0 J0 oint 9 . Technical D raft National Transportation S ystem s Center has develope d a S upport D ocum ent: P roposed R ulem ak ing toLEstablish ight- D uty V em odel for the NH TS A to estim ate how m anufacturers can hicle Greenhouse Gas Em ission S tandards and Corpora te A verage F uel Econom y S tandards, EP A - 4 2 0 - D - 0 9 - 9 0 1 , S eptem ber. com ply with fuel econom y regulations by applyingditional ad Greene, D . L . , and J . D eCicco. 2 0 0 0 . Engineeringnom ic analysis eco of fuel savings technologies to the vehicles they plan to produce. autom otive fuel econom y potential in the U nited tes.S Ata nnual R eview The m odel em ploys a P D A algorithm that includes im atesest of Energy and the Environm ent 2 5 :4 7 7 - 5 3 6 . of the effects of technology synergies. The validity of the H ancock , D . 2 0 0 7 . A ssessing fuel econom ion to y. the P resentat Com m ittee V olpe m odel, and probably also the OM EGA m ldodel, couon F uel Econom y of L ight- D uty V ehicles, National search Council, R e S eptem ber 1 0 , W ashington, D . C. be im proved by m ak ing use of m ain effects and action inter K asseris, E. P . , and J . B. H eywood. 2 0 0 7 analysis . Com ofparative autom otive effects produced by the F S S m ethodology described n thisi powertrain choices for the nex t 2 5 years. S A Eical Techn P aper S eries chapter. In particular, research done for the com ttee m ihas No. 2 0 0 7 - 0 1 - 1 6 0 5 . S A E International, . W arrendale, P a

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

MODELING IMP R OV EMENTS IN V EH ICLE F U EL CONSU MP TION

13 7

K rom er, M . A . , and J . B. H eywood. 2007rtrains: . Electric opportunities powe R icardo, Inc. 2 0 0 9 . A S tudy of Interaction Between EffectsL ight D uty and challenges in the U . S . light- duty vehicle leet. P ublication No. L F EE V ehicle Technologies. P repared for the NR C Come on m Aittessessm ent 2 0 0 7 - 0 2 R P . S loan A utom otive L aboratory, tts Institute M assachuse of of Technologies for Im proving L ight- D uty V ehicle el Econom F u y by Technology, Cam bridge, M ass. R icardo Inc. , V an Buren, M ich. , F ebruary 2 7 . M ark el, T. , A . Brook er, T. H endrick s, V. K . J elly, ohnson, B. KK ram er, R ousseau, A . 2 0 0 7 . D esigning advanced vehicle trains power using P S A T. M . O’K eefe, S . S prik , and K . W ipk e. 2 A 0 0 system 2 . A sD V ISP OR resentation : to the Com m ittee on F uel Economghty ofDL uty i V ehicles, analysis tool for advanced vehicle m odeling. J ourna l of P ower S ources National R esearch Council, S eptem ber 1 0 . 1 1 0 ( 2 ) :2 5 5 - 2 6 6 . S ierra R esearch, Inc. 2 0 0 8 . Technology and riceretail im pplications of H R 6 M osk wa, J . 2 0 0 8 . P owertrain Control R esearch tory, UL niversity abora of CA F E standards based on vehicle sim ulation m odeling ( prelim inary W isconsin, M adison, W isc. results) . P resentation to the com m ittee by J am L yons, es M J . anuary 2 4 . NES CCA F ( Northeast S tates Center for a Cleanture) A ir.F2 u0 0 4 . R educing S ovran, G. , and D . Blaser. 2 0 0 3 . A contribution to understanding autom otive Greenhouse Gas Em issions from L ight- D uty M cles. otor V M ehi arch. fuel econom y and its lim its. S A E P aper 2 0 0. S3 -A0 E1 Interna-2 0 7 0 NR C ( National R esearch Council) . 2 0 0 2 . Effectivenes s and Im pact of tional, W arrendale, P a. Corporate A verage F uel Econom y S tandards. National A cadem y P ress, S ovran, G. , and D . Blaser. 2 0 0 6 . Q uantifying tential im the po pacts of reW ashington, D . C. generative brak ing on a vehicle’s tractive- fuel con sum ption for the U . S . , P atton, K . J . , A . M . S ullivan, R . B. R ask , and M . A . Theobald. 2European, 0 0 2 . AandggregatJ apanese driving schedules. S A E P2 aper 0 0 6 -0 1 -0 6 6 4 . ing technologies for reduced fuel consum ption: A view re of the technical S A E International, W arrendale, P a. content in the 2 0 0 2 National R esearch Council tRonepor CA F E. S A E S ovran, G. , and M . S . Bohn. 1 9 8 1 . F orm ractiveulaeenergy for thereq t uireP aper 2 0 0 2 - 0 1 - 0 6 2 8 . S A E International, P a. W arrendale, m ents of vehicles driving the EP A schedules. S per A 8E 1P 0a 1 8 4 . S A E R icardo, Inc. 2 0 0 8 a. A S tudy of P otential Effectiveness Carbon D ofiox ide International, W arrendale, P a. R educing V ehicle Technologies. P repared for the. U Environm .S ental V an S chalk wyk , J . , W . Gaz da, K . Green, and M D .. PS ick haulov. rell, 2 0 0 9 . P rotection A gency, EP A 4 2 0 - R - 0 8 - 0 0 4- ,C-Contract 0 6 - 0 No. 0 3 EP , Corporate average fuel econom y com pliance and effect s m odeling W ork A ssignm ent No. 1 - 1 4 , A nn A rbor, M ich. system docum entation. D OT H S 8 1 1 0 1 2 nt . U of Trans. S . D epartm e R icardo, Inc. 2 0 0 8 b. A study of potentialness effective of carbon diox ide portation, R esearch and Innovative Technology A dm istration, in Energy reducing vehicle technologies. P resentation to theCom m ittee on Technology D ivision, J ohn A . V olpe National Transpo rtation S ystem s F uel Econom y of L ight- D uty V ehicles, National rch RCouncil, esea Center, Cam bridge, M ass. , A pril. J anuary 2 4 . W aters, W . C. 1 9 7 2 . General purpose automle perform otive vehic ance and econom y sim ulator. S A E P aper 7 2 0 0 4 3 E . JInternational, anuary 1 0 . S A W arrendale, P a.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

9 Application of Vehicle Technologies to Vehicle Classes

INTRODUCTION

DEVELOPING BASELINE VEHICLE CLASSES

In conducting its assessm ent of technology applicab ility to different vehicle classes, the com m ittee wasded guiby the following q uestion included in the statem ent task of : “W hat are the estim ated cost and potential fuel nom eco y beneits of technology that could be applied to im pr ove fuel econom y of future passenger vehicles, given the con straints im posed by vehicle perform ance, functionality, safety and and em ission regulations?Note ” that applying technology to im prove fuel econom y and reduce fuel consum ption ouldsh not be interpreted to m ean sim ply attaching a com nentpoor subsystem that then achieves a subseq uent reduction in fuel consum ption. S uch reductions in fuel consum ption pically ty evolve through an increm ental, evolutionary applica tion of com ponents, subsystem s, and new power train or cle vehi technologies. P revious chapters of this report have provided tech nical sum m aries of current and advanced technologies that are currently being applied to vehicles, or developed forfuture vehicle applications. Other reports from the National R esearch Council ( NR C) have also look ed at the im pacts chnoloof te gies for reducing fuel consum ption—A ppendix H des provi a sum m ary of other recent NR C studies relatedghtto liduty vehicle technologies. M any of these technologies uld, co in principle, be applied to alm ost any vehicle. H ow er, evthe intended use of the vehicle, its price range, consum er characteristics, em issions and safety standards com nce, plia and pack aging constraints inluence which technologies will see m ark et penetration on different vehicle types. M any of the technologies have already seen signiica nt penetration into European or A sian m ark ets where gulare tory and m ark et pressure, including signiicant tax tionathat results in high fuel prices for consum ers, have enc ouraged early adoption. Others, such as turbocharged, direc t- injection gasoline engines, have gained signiicant attention in the U nited S tates because fuel consum ption can be reduc ed with m inim al redesign of the total vehicle system .

The concept of dividing U . S . passenger vehicleso int socalled classes is both an outcom e of regulatory seg m entation for the purpose of varying standards and a m eans wh ereby vehicle sales categories are differentiated by vehicle siz e, geom etry, and intended use. The NR C CA F E report gse m ented U . S . passenger vehicle sales into 1 0 that classes were a subset of the larger num ber of type and weight asses cl that the U . S . EP A uses as part of its vehicle certiicati on process ( NR C, 2 0 0 2 ) . These 1 0 classes are as follows: 1 . S m all S U V , 2 . M edium S U V , 3 . L arge S U V , 4 . M inivans, 5 . S m all pick ups, 6 . L arge pick ups, 7 . S ubcom pact cars, 8 . Com pact cars, 9 . M idsiz e cars, and 1 0 . L arge cars. The statem ent of task directs the current com m toittee evaluate these vehicle classes and update the technology outlook for future m odel introduction. H owever, fts shi in consum er preference and vehicle sales have been sig niicantly inluenced by the recent instability in fuel prices, vehicle inancing costs, U . S . and global econom ic itions, cond and regulatory uncertainty. S igniicant shifts in ve hicle sales between 2 0 0 2 and 2 0 0 7 showed a continuing inincrease S U V sales, with sales of sm all pick ups essentially disappearing ( EP A , 2 0 0 8 a) . H owever, in 2 0 0 8in, fuel large increases price ( above $ 4 per gallon of gasoline) resulteda in greater than 5 0 percent reduction in the sale of m idsizdelarge an S U V s. S ubseq uent U . S . and global instability inancial in the m ark ets, followed by a period of recession, hasulted res in an overall reduction of vehicle sales in the U nitedS tates of m ore than 2 0 percent from 2 0 0 8 to 2 0 0 9 .

13 8

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

AP P LICATION OF V EH ICLE TECH NOLOGIES TO V EH SES ICLE CLAS

Therefore, the choice of vehicle classes for futureconsideration as part of this assessm ent of potential fue l econom y technologies should focus on vehicle siz e, weight,ntei rior passenger volum e, intended use, and the potent ial for im plem entation of nex t- generation power trains, luding inc hybrid electrics. Based on various factors outlinedbelow, the following classiication of light- duty vehicles inthe U nited S tates was determ ined by the com m ittee to beropriate an app basis for future technology developm ent and introdu ction into production. 1

2

3

4

5

13 9

of under 0 . 0 5 5 including crossover vehicles, S U V s, and m inivans. M ost vehicles em ploy front- wheel drive. The average 2 0 0 7 m odel- year vehicle for this class was developed from EP A ( 2 0 0 8 a) and has the following characteristics: a six - cylinder, four- ve, val dual overhead cam engine with intak e cam phasing and a 6 - speed autom atic transm ission. The average vehicle for this class is used as the base vehicle in the estim ation of fuel consum ption reductions for mpleulti technologies as discussed later in this chapter. 6 .U nit- b o dy hig h- p erfo rmance —Crossover tru ck svehi.Tw o - seater co nvertib l es and co —Su mp es all vehicles cles, S U V s, and m inivans with hp/ lb of vehicle ht weig by interior volum e whose function is high- performce an ratios of 0 . 0 5 5 or greater. M ost have rear- ive wheel dr and handling. The average 2 0 0 7 m odel- year vehicle or f ( R W D ) or all- wheel drive ( A W D ) and unibody co this class was developed from EP A ( 2 0 0 8 a) he and has t struction, and m ost are lux ury vehicles. The averag e following characteristics: a six - cylinder, four- ve, val 2 0 0 7 m odel- year vehicle for this class was develope d dual overhead cam engine with intak e cam phasing from EP A ( 2 0 0 8 a) and has the following characterisand a 6 - speed autom atic transm ission. The average tics: a six - cylinder, four- valve, dual overhead cam envehicle for this class is used as the base vehicle in the gine with intak e cam phasing and a 6 - speed autom c ati estim ation of fuel consum ption reductions for mpleulti transm ission. The average vehicle for this class used is technologies as discussed later in this chapter. as the base vehicle in the estim ation of fuel consu m p.Smal l cars —M ini- , sub- , and com pact cars, standard tion reductions for m ultiple technologies as discus sed perform ance, m ostly four- cylinder, m ostly front- wheel later in this chapter. drive ( F W D ) , including sm all station wagons. The 7 .B o dy - o n- frame smal l and midsiz—P e truickck ups s less average 2 0 0 7 m odel- year vehicle for this class de- was than or eq ual to 1 , 5 0 0 lb payload capacity ( CEC s clas veloped from EP A ( 2 0 0 8 a) and has the following char 1 4 ) and S U V s of up to 1 7 5 cubic feet of passenger acteristics: a four- cylinder, four- valve, dual over head volum e plus cargo volum e with R W D or A W D . T cam engine with intak e cam phasing and a 6 - speed average 2 0 0 7 m odel- year vehicle for this class was autom atic transm ission. The average vehicle fors thi developed from EP A ( 2 0 0 8 a) and has the following class is used as the base vehicle in the estim ationof characteristics: a six - cylinder, two- valve, single overfuel consum ption reductions for m ultiple technologi es head cam engine with a 5 - speed autom atic transm isas discussed later in this chapter. sion. The average vehicle for this class is used as the .Intermediate and l arg e cars —S tandard perform ance, base vehicle in the estim ation of fuel consum ption m ostly F W D , m ostly six - cylinder, including largereductions for m ultiple technologies as discussedater l station wagons with less than 0 . 0 7 hp/ lb of vehicle in this chapter. weight. The average 2 0 0 7 m odel- year vehicle s for thi 8 .B o dy - o n- frame l arg —P e truick ck ups s of greater than class was developed from EP A ( 2 0 0 8 a) and has the 1 , 5 0 0 lb payload but less than 1 0 , 0 0 0 lb GV W , following characteristics: a six - cylinder, four- ve, val S U V s with 1 7 5 cubic feet or greater of passenger dual overhead cam engine with intak e cam phasing plus cargo volum e with R W D or A W D , including al and a 4 - speed autom atic transm ission. The average standard vans, cargo and passenger. The average 2 07 0 vehicle for this class is used as the base vehicle in the m odel- year vehicle for this class was developed fro m estim ation of fuel consum ption reductions for mpleulti EP A ( 2 0 0 8 a) and has the following characteristics: technologies as discussed later in this chapter. an eight- cylinder, two- valve, overhead valve engine .H ig h- p erfo rmance sedans —P assenger cars with with a 4 - speed autom atic transm ission. The average greater than or eq ual to 0 . 0 7 hp/ lb of vehiclehtweig vehicle for this class is used as the base vehicle in the that are not two- seaters. The average 2 0 0 7 m arodel- ye estim ation of fuel consum ption reductions for mpleulti vehicle for this class was developed from EP A (a)2 0 0 8 technologies as discussed later in this chapter. and has the following characteristics: a six - cylind er, four- valve, dual overhead cam engine with intak me ca These eight classes allow an evaluation of sim ilarbase phasing and a 6 - speed autom atic transm ission. Thevehicles designs, where the vehicle siz e, baseline chassis average vehicle for this class is used as the base vehicle coniguration, aerodynam ic characteristics, vehicle weight in the estim ation of fuel consum ption reductionsr fo and type of drive train ( F W D , R W D , and Ailar. W D ) are s m ultiple technologies as discussed later in this ch apter. This grouping should result in vehicle classes where sim ilar .U nit- b o dy standard —Nontru ck spick up truck s with calibration criteria are associated with sim ilar ve hicle perunibody construction and hp/ lb of vehicle weight ratios form ance characteristics. A greater num ber ofesclass would

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

14 0

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

also be possible if there was a desire to narrow the variability in vehicle characteristics in each class.

been considered proprietary by autom obile m anufactu rers ( referred to as original eq uipm ent m anufacturers; EM Os) and suppliers, such that only those com panies associated with the design, developm ent, and production of such system have s ESTIMATION OF FUEL CONSUMPTION BENEFITS had the data to conduct such analyses. H owever, par tnerships Increm ental reductions in fuel consum ption through currently ex ist between the autom otive industry and the U . S . the application of technologies were estim ated byhe t governm ent such that m ore com plete ex perim aental will dat com m ittee. A s discussed earlier in this report, ut cam inp e be m ade available in the future. from m any sources including com ponent suppliers, hicleve A nother factor in successfully m odeling full vehicl e sysm anufacturers, and the review of m any publishedlyses ana tem s is the need to understand and capture the trad eoffs that conducted by, or for, the U . S . D epartmTransportation ent of OEM s m ust m ak e in developing inal production calibrations National H ighway Trafic S afety A dm inistration (ANH) , TSof vehicles and their power trains. Calibration isthe process U . S . Environm ental P rotection A gency ( EP nia A ) , Califor of power train and vehicle perform ance optim iz ation that A ir R esources Board ( CA R B) , and other agencies rade or t focuses on achieving predeterm ined perform ance,vabildri associations. The com m ittee also contracted with veral se ity, fuel consum ption, durability, fuel octane sens itivity, and consultants to provide input. m any other param eters while still com plying with atutory st R elative reductions in fuel consum ption can result from req uirem ents such as those for levels of em issions, onboard several factors, m any of which are interrelated: diagnostics ( OBD ) , and safety standards. In particu lar, m any potential technologies that can be applied for im pr oving fuel • R eduction in the tractive force needed to propelthe consum ption could inluence perform ance param eters uch s vehicle ( reduced rolling resistance, aerodynam icag, dr as 0 - 6 0 m ph acceleration tim es, vehicle passing abil- cap vehicle weight, etc. ) ; ity, towing capability, transm ission shift q uality, or noise • Im provem ent in the energy conversion eficiency f o and vibration characteristics. D ifferent m anufactur ers m ust the fuel in the engine into m ax im um usable energythus determ ine their custom er- preferred com prom and ises through increased therm al eficiency ( com pression calibrate the vehicle control algorithm s accordingl y. Based ratio increase for gasoline engines, lean com bustio n, on the num ber of potential param eters that m ayaried be vin diesel, etc. ) ; m odern passenger car engines, tens of thousands com of bina• R eductions in the engine and power train energylosses tions are possible. Therefore, m anufacturers andlibration ca that consum e portions of the available energy befor e service com panies have developed optim iz ation egies strat and after com bustion ( gas ex change losses, power train and algorithm s to ine- tune these variables while hieving ac friction, accessory losses, etc. ) ; an OEM ’s criteria for perform ance and drivability ithin w the • Optim iz ation of operational param eters thatwallo constraints of em issions, fuel econom y, and other tandards. s the engine to run in regions of highest eficiency Calibration logic is norm ally a highly conidentialprocess ( increased num ber of transm ission gears, CV Ts, imthat- req uires the ex perience of com panies involved in the proved lugging characteristics, aggressive shift logic, production release of vehicles ( OEM s, Tier 1 supplie rs, etc. ) ; and production engineering services com panies, etc. ) accuto • S om e form of hybridiz ation that allows other m for s of rately assess the necessary perform ance, fuel consu m ption energy capture, storage, and m anagem ent to reduce he t and ex haust em ission, and drivability tradeoffs accurate for total energy consum ed over the driving cycle. m odeling. P artial discrete approx im ation ( P D A ) and lum ped The com m ittee think s that the m ost accurate mof ethodparam eter m odeling techniq ues, as described inpter Cha8 , analyz ing potential reductions in fuel consum ption, which ex am ine and estim ate increm ental reduction inconfuel considers the ex tent to which any of the eficiencyim provesum ption associated with applications of discreteechnolot m ents or energy loss reductions identiied above canbe gies or subsystem s and their effect on reducing ene rgy losses. realiz ed while m aintaining energy balance criteria, utiliz es They represent a m ore tim e- and cost- effective od m ofeth full system sim ulation ( F S S ) . This analysis ue,techniq as estim ating potential reductions in fuel consum ption and described in Chapter 8 , represents the state of theart in prem ay incorporate routines that attem pt to tabulate r account o dicting vehicle perform ance, fuel consum ption, ctdire CO2 for aggregation of energy- loss reductions that focus on luid em issions, and other regulated and non- regulated issions. em m echanical losses, frictional losses, and heat tran sfer losses. H owever, F S S analyses req uire detailed vehicle, ine, eng H owever, the ultim ate accuracy of such analysesiesrelon a transm ission, accessory, and other subsystem data, typically suficiently broad set of em pirical or system - sim tionula data ex pressed in the form of data m aps that q uantify wer,po that do not necessarily provide enough detail to understand torq ue, fuel consum ption, and ex haust em issions r theove the base test vehicle distribution of energy losses. Calibracom plete range of operation. H istorically, sucha (dat which tion of such m odels against actual test vehicles pr ovides a m ay not yet ex ist for the m ost advanced technologie s) have benchm ark of the m odeler’s attem pt to m atchance perform

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

AP P LICATION OF V EH ICLE TECH NOLOGIES TO V EH SES ICLE CLAS

14 1

data, but does not provide the sam e level of ex plan ation of m odeled vehicles or power trains against which toeine r the the subsystem contribution to total vehicle energy losses that estim ates. This variability in estim ates for fuel onsum c ption is accom plished in the F S S cases. F urtherm inluore, the reductions also relects the fact that different OEMs m ay ences of variations in calibration strategies owing to such obtain different beneits from the sam e technology ue dto factors as driver com fort; noise, vibration, andrshness ha differences in im plem entation and calibration. A , posilso (NV H ) - related issues; and perform ance/ em issions eoffs trad tive beneits m ay vary depending on the particularngine/ e are typically not considered in such analyses. transm ission/ vehicle architecture. These factorsve habeen W ith either m odeling approach, it is im perative underto considered by the com m ittee in its range of estim es oratits stand the role that any previously applied technologies play decision to include or ex clude the potential application of in reducing energy losses and/ or im proving the ther m otechnologies into different technology paths. Note that the dynam ic eficiency of the power train. ranges associated with these technologies do not relect the possibility that, over tim e, the average fuel consu m ption beneit could tend toward the high end of the range as the APPLICABILITY OF TECHNOLOGIES TO VEHICLE lessons learned from the best ex am ples of the techn ology CLASSES spread across the industry and as the im pacts of gher hi CA F E Not all of the technologies identified in Chapters 4 standards increase. A lthough the com m ittee recogniz es that through 7 of this report can be justiiably appliedto all vethe im plem entation of these technologies with fuel consum phicle types. A pplicability of the technologies tohet various tion beneits at the higher end of the ranges could occur, it is vehicle classes req uires an analysis of param etric tradeoffs dificult to assert that this will occur or to what degree this which considers functionality, intended use, im pact on warwould im pact the average consum ption beneit over m tie. ranty, ease of im plem entation, product cycle tim , ming ark et The issue of how m ultiple technologies m ight intera ct dem and, cost- effectiveness, and m any other factors. S om e when used to reduce fuel consum ption is critical. SF S technologies m ay be discounted for technical reason s, for analyses conducted by R icardo, Inc. , for the EP nd A fora ex am ple, the lim itations of continuously variable ransmt isthe com m ittee shed som e light on the issue of gistic syner sions ( CV Ts) in transm itting high torq ue on vehicle classes interaction of m ultiple technologies that m ay attem pt to rewith larger engines where towing or off- road capability is duce energy losses of a sim ilar type, such as pumngpi losses a prim ary product feature. Others m ay be ex cluded asedb ( R icardo, Inc. , 2 0 0 8 , 2 0 0 9 ) . These analyses e need show th on the intended purpose of the vehicle. F or ex am, lowple to carefully understand the contribution of technologies in rolling- resistance tires appear to be a cost- effect ive m eans of reducing losses whose im pact m ay be only a 1 toercent 2 p reducing fuel consum ption, potentially justifyingheir t use reduction in fuel consum ption. The R icardo, Inc. nalyses , a on all vehicles. H owever, in higher perform ance sses claof also show that the type of vehicle and power train inluences vehicles, where tire grip is an im portant producteature f or the ex tent to which different technologies reduce uel f confor S U V applications where the vehicle m ay travel ff- road, o sum ption, especially between vehicles of different classes the use of such tires is lik ely restricted. with different intended uses. This effect is discussed in Table 9 . 1 shows the com m ittee’s estim ationmof enincre Chapter 8 , where the prim ary effect of synergiesswa shown tal reductions in fuel consum ption that m ay be ex pected from to dom inate the potential for im provem ent. A gly, ccordin the application of different technologies and ranges associsecondary effects of inluences that interact across technolated with the reductions. In general, the com m estim ittee ated ogy im provem ent paths were found to be m inor. what it considered to be the average fuel consum pti on reduction for a technology before it attem pted to est im ate the ESTIMATING INCREMENTAL COSTS ASSOCIATED range. These data, shown in the form of ranges, in aresom e WITH TECHNOLOGY EVOLUTION cases dependent upon the level of technology applied to a vehicle before the nex t increm ent is tak en. A sied identi above, Chapter 3 describes the m ethodologies used for the estithese data represent estim ates by the com m ittee eloped dev m ation of increm ental costs associated with theroduction int from evaluating published data, and analyses conduc ted by of advanced technology for reducing fuel consum ptio n. A the NH TS A , the EP A , and others. A ppendix results I containsrange of estim ated costs was also prepared and isutlined o in from som e of these other studies, although the er read should the technology sections presented in Chapters 4 through 7 . refer to the original source for the assum ptions an d study Table 9 . 2 shows the collection of these cost estim tes for a all approaches used in these other studies. The ex pert judgm ent technologies included in this report. The cost estim ates repof m em bers of the com m ittee whose careers have sedfocu resent estim ates for the current ( 2 0 0 9 / 2 0 eriod 1 0 )totim e p on vehicle and power train design and developm ent ewre about 5 years in the future. A s with the data onelfu consum palso incorporated in the estim ates. Ex am ination theofdata tion reductions, increm ental cost inform ation was rovided p in Table 9 . 1 suggests that signiicant variations estim in ates to the com m ittee by OEM s, Tier 1 suppliers, and studies pubof the potential for reducing fuel consum ption are due to the lished by trade associations, governm ental agencies , m anulack of detailed sim ulation data on actual or theor etically facturing consultants, and earlier NR C reports. Aendix pp I

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

14 2

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

TA BL E 9 . 1 Com m ittee’s Estim ates of Effectiveness hown as a (percentage) s of Near- Term V ehicle F uel Consum ption

TechnologiesRin educing

Incremental values - A preceding technology must be included

Technologies

I4

Spark Ignition Techs

Abbreviation

Low Friction Lubricants

LUB

Low 0.5

High 0.5

Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete V ariable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC

EFR CCP DVVL DEAC

0.5 1.5 1.5 NA

2.0 3.0 3.0 NA

VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete V ariable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete V ariable Valve Lift (DVVL), OHV Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel Techs

ICP DCP DVVL CVVL DEAC CCP DVVL SGDI TRBDS

1.0 1.5 1.5 3.5 NA 1.5 1.5 1.5 2.0

2.0 2.5 3.0 6.0 NA 3.0 2.5 3.0 5.0

V6

A VG 0.5 1.3 2.3 2.3 NA 1.5 2.0 2.3 4.8 NA 2.3 2.0 2.3 3.5

V8

Low 0.5 0.5 1.5 1.5 4.0

High 0.5 2.0 3.5 3.0 6.0

AVG 0.5 1.3 2.5

1.0 1.5 1.5 3.5 4.0

2.0 3.0 3.5 6.5 6.0

1.5 2.3

1.5 1.5 1.5 4.0

3.5 3.0 3.0 6.0

2.5 5.0 5.0 2.5 2.3 2.3 5.0

2.3 5.0

Low 0.5 1.0 2.0 2.0 5.0 1.5 1.5 2.0 4.0 5.0 2.0 2.0 1.5 4.0

High 0.5 2.0 4.0 3.0 10.0 2.0 3.0 4.0 6.5 10.0 4.0 3.0 3.0 6.0

AVG 0.5 1.5 3.0 2.5 7.5 1.8 2.3 3.0 5.3 7.5 3.0 2.5 2.3 5.0

DSL

15.0

35.0

25.0

15.0

35.0

25.0

NA

NA

NA

Conversion to Advanced Diesel Electrification/Accessory Techs

ADSL

7.0

13.0

10.0

7.0

13.0

10.0

22.0

38.0

30.0

Electric Power Steering (EPS) Improved Accessories Higher Voltage/Improved Alternator Transmission Techs

EPS IACC HVIA

1.0 0.5 0.0

3.0 1.5 0.5

2.0 1.0 0.3

1.0 0.5 0.0

3.0 1.5 0.5

2.0 1.0 0.3

1.0 0.5 0.0

3.0 1.5 0.5

2.0 1.0 0.3

Continuously Variable Transmission (CVT) 5-spd Auto. Trans. w/ Improved Internals 6-spd Auto. Trans. w/ Improved Internals 7-spd Auto. Trans. w/ Improved Internals 8-spd Auto. Trans. w/ Improved Internals 6/7/8-spd Auto. Trans. w/ Improved Internals 6/7-spd DCT from 4-spd A T 6/7-spd DCT from 6-spd A T Hybrid Techs

CVT

1.0 2.0 1.0

7.0 3.0 2.0

4.0 2.5 1.5

1.0 2.0 1.0

7.0 3.0 2.0

4.0 2.5 1.5

1.0 2.0 1.0

7.0 3.0 2.0

4.0 2.5 1.5

3.0 6.0 3.0

8.0 9.0 4.0

2.0 1.0 5.5 7.5 3.5

3.0 6.0 3.0

8.0 9.0 4.0

2.0 1.0 5.5 7.5 3.5

2.0 29.0 24.0 25.0 NA

4.0 39.0 50.0 45.0 NA

3.0 34.0 37.0 35.0 NA

2.0 29.0 24.0 25.0 NA

4.0 39.0 50.0 45.0 NA

3.0 34.0 37.0 35.0 NA

3.5 7.0 13.0 3.0

0.3 1.4 3.3 6.5 12.0 2.0 1.0 1.5

3.5 7.0 13.0 3.0

0.3 1.4 3.3 6.5 12.0 2.0 1.0 1.5

Conversion to Diesel

2.0 1.0 NAUTO DCT DCT

3.0 6.0 3.0

8.0 9.0 4.0

2.0 1.0 5.5 7.5 3.5

12V BAS Micro-Hybrid Integrated Starter Generator Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs

MHEV ISG PSHEV 2MHEV PHEV

2.0 29.0 24.0 25.0 NA

4.0 39.0 50.0 45.0 NA

3.0 34.0 37.0 35.0 NA

Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Aero Drag Reduction 10%

MR1 MR2 MR5 MR10 MR20 ROLL LDB AERO

3.5 7.0 13.0 3.0

0.3 1.4 3.3 6.5 12.0 2.0 1.0 1.5

0.3 1.4 3.0 6.0 11.0 1.0 1.0

1.0

2.0

2.0 1.0

0.3 1.4 3.0 6.0 11.0 1.0 1.0

1.0

2.0

2.0 1.0

0.3 1.4 3.0 6.0 11.0 1.0 1.0

1.0

2.0

NOTE: S om e of the beneits ( highlighted in green) e increm ar ental to those obtained with preceding tech nologies shown in the technology pathways described in Chapter 9 .

contains results from som e of these other studies, although, again, the reader should refer to the original source for the assum ptions and study approaches used in these othe r studies. D uring the data gathering process, it becamlear e cthat the estim ated increm ental cost ranges were, in mcases, any very large, depending on the boundary conditions identiied by the organiz ation offering the inform ation. Gener ally, the com m ittee notes that cost estim ates are always uncerm ore tain than the fuel consum ption im pact estim ates, d the an estim ates presented here should be considered veryuncertain until m ore detailed studies are com pleted. oundary A b condition in the cost estim ations is an assum ption of long-

term , high- volum e production, whereby analysts m atte pt to norm aliz e all increm ental costs into a scenario rewhe the capitaliz ed developm ent cost becom es a sm allnportio of the inal unit production cost. This is accom plished by assum ing that production volum es are several hundred thousan d units per year and rem ain in production for m any years. A lthough this assum ption m ay be q uite appropriate o t norm aliz e overall annual societal costs, it doest no necessarily recogniz e the initial developm ent- based costs nd aq uality hurdles that m ay prevent a m anufacturer from pursui ng new product or technology areas. F or ex am ple, suchyses anal would not consider factors that m ay inhibit or prev ent the

Technologies

Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance T ires Aero Drag Reduction 10%

Continuously Variable Transmission (CVT) 5-spd Auto. T rans. w/ Improved Internals 6-spd Auto. T rans. w/ Improved Internals 7-spd Auto. T rans. w/ Improved Internals 8-spd Auto. T rans. w/ Improved Internals 6/7/8-Speed Auto. T rans. with Improved Inter nals 6/7- spd DCT from 6-spd AT 6/7- spd DCT from 4-spd AT Hybrid Techs 12V BAS Micro-Hybrid Integrated Starter Gener ator Power Split Hybrid 2-Mode Hybrid Series PHEV 40 Vehicle T echs

Conversion to Diesel Conversion to Advanced Diesel Electrification/Accessory Techs Electric Power Steering (EPS) Improved Accessories Higher Voltage/Improved Alternator Transmission Techs

37 77 217 520 1600 30 40

450 1760 2708 5200 8000

MHEV ISG PSHEV 2MHEV PHEV MR1 MR2 MR5 MR10 MR20 ROLL AERO

137 -147 -14

NAUT O DCT DCT

133 170

150

70 70 15

EPS IACC HVIA CVT

2154 520

130 117 370

130 159 NA

130 NA

35

425 185 400

215 300

170

120 90 55

2632 520

160 195 490

160 205 NA

45 93 260 624 1700 40 50

550 2640 4062 7800 12000

425

133

35

35 35

160 NA

5 52.0

3 32.0

DSL ADSL

Abbreviation LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL SGDI TRBDS

High

Low

143 120 53 240 200 262 353 638 422 29 290 665 2926 4502 8645 13300 61 127 358 859 2475 53 68

95 80 35 160 133 174 235 425 281 19 193 500 2200 3385 6500 10000 41 85 239 572 1650 35 45

48 100 283 679 1600 30 40

585 2000 3120 5200 9600

137 -147 -14

133 170

243

70 70 15

425 185 400

215 300

263

58 121 339 815 1800 40 50

715 3000 4680 7800 14400

425

133

120 90 55

3491 683

53 111 311 747 1700 35 45

650 2500 3900 6500 12000

253 133 174 235 425 281 19 193

95 80 35

80 166 467 1 120 2550 53 68

865 3325 5187 8645 15960

380 200 262 353 638 422 29 290

143 120 53

4761 1025

68 142 399 958 1600 30 40

720 3200 4000 5200 13600

137 -147 -14

133 170

243

70 70 15

NA 3513

425 185 400

215 300

263

82 170 479 1 150 1900 40 50

880 4800 6000 7800 20400

425

133

120 90 55

NA 4293

NA 3903

2857 683

75 156 439 1054 1750 35 45

800 4000 5000 6500 17000

253 133 174 235 425 281 19 193

95 80 35

AVG

3174 683

V8 4 84 70 300 388.5 70 70 280 370 255 35 300 323 658

3590 780

4 42 35 145 NA 35 35 145 182 NA 35 145 156 430

AVG

Incremental Values - A preceding technology must be included V6 AVG w/1.5 AVG w/1.5 Low Low High AVG High RPE RPE 4 6 3 5 6 3 5 63 48 78 63 94.5 64 104 52.5 70 105 70 70 217.5 180 210 195 292.5 280 320 NA 340 400 370 555 357 420 70 52.5 105 70 70 70 52.5 105 70 70 217.5 180 220 200 300 260 300 273 290 310 300 450 350 390 NA 220 250 235 352.5 255 52.5 35 52.5 35 35 225 218 210 240 338 280 320 213 234 169 256 319 295 351 -144 205 31 525 790 645 46

2393 520

I4

NR C 2009 Costs

Com m ittee’s Estim ates of Technology in U Costs . S . D ollars ( 2 0 0 8 )

Spark Ignition Techs Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel T echs

TA BL E 9 . 2

1 13 234 659 1581 2625 53 68

1064 5320 6650 8645 22610

380 200 262 353 638 422 29 290

143 120 53

NA 5855

AVG w/1.5 RPE 6 126 105 450 582.75 105 105 420 555 382.5 52.5 450 485 986

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

AP P LICATION OF V EH ICLE TECH NOLOGIES TO V EH SES ICLE CLAS

14 3

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

14 4

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

introduction of diesel technology into passenger vehicles due ( A uto A lliance) , used the D OE- supported V EH l S IM m o to the signiicant investm ent and general lack ofmfa iliarity to estim ate fuel consum ption reduction for various techof North A m erican autom otive OEM s and suppliers in the nologies using a com posite of engine m aps provided by production of sm all, light- duty diesels and the ability dur of m anufacturers. A lthough the com m ittee recom mm ore ends a necessary ex haust aftertreatm ent system s. Thisesserv as a practical approach to apply F S S for future regulatory actions, rem inder that, while overall costs to the industry of new techwhich is discussed later in this chapter, the ex clu sive use of nologies is an im portant consideration, it is thendividual i F S S sim ulation for the assessm ent of all technologi es conm anufacturers that bear the risk in adapting a tech nology to sidered under this study was not possible. The com ittee m bea speciic vehicle and this risk m ay not be fullyptured ca in lieves that suficient ex perim ental data can be gath ered by the a m etric of overall industry costs. governm ent to support future analysis and regulato ry activiThe com m ittee was briefed on the very detailed and ties through consortia that include both regulatory agencies transparent teardown cost assessm ent m ethodologying be and autom otive m anufacturers and suppliers. utiliz ed by the EP A as part of the process formestiating the W ith this back ground, the com m ittee evaluated tialpoten cost of fuel econom y technologies. Cost estim ation using technology paths that could be considered by a m anufacturer, the teardown approach is discussed in Chapter 3 . Th e com depending upon the m anufacturer’s actual state ofechnolt m ittee inds this approach an im provem ent over one herew ogy and production capability. R ather than creating decision cost estim ates are developed through ex pert k nowled ge and trees from which an ex trem ely large num ber of blepossi techsurveys of suppliers and OEM s, which have been the basis nology com binations could be created for each vehic le class, for m ost published studies and the m ajority of this report. the com m ittee estim ated possible technology evolution paths F urtherm ore, the com m ittee recom m ends that of the use for each class that develop from the average baseli ne vehicle. teardown studies be ex panded for future assessm ents when These pathways are sum m ariz ed in F igures 9 ..1 to 9 . 5 cost- effectiveness is an im portant evaluation crite rion. The baseline attributes were determ ined on a classbyclass basis using the 2 0 0 7 EP A test list. cent If 5 of 1 the per vehicles in a given class had variable valve tim ing( V V T) , ASSESSING POTENTIAL TECHNOLOGY SEQUENCING then the baseline, class- representative vehicle wasgiven PATHS V V T, and this technology would not be added in path. the W hen m anufacturers consider a strategy for im plem tenBecause the characteristic vehicle in each class represents the ing technologies that reduce fuel consum ption, a rm no al average attributes for that class, there will be som e vehicles business decision process m ust tradeoff m any differ ent in that class that have m ore or less technology con tent. The param eters, including cost- effectiveness ( fuel cons um ption below- average vehicles m ay req uire additional techn ologies reduction versus production cost) , the ability to eb integrated and associated costs to address future standards while the into product planning cycles, intended product use, reliabove- average vehicles m ay not. U sing the average attributes ability, im pact on vehicle perform ance characterist ics, and should provide a good overall representation of technology custom er acceptance. To conduct the current assessm ent, the beneits relative to the baseline leet within a class of vecom m ittee em ployed a m ethod whereby cost- effectiven ess hicles. The technologies of the baseline vehicles are listed ( fuel consum ption reduction divided by high- volum pro-e in the title bar of each technology path. duction increm ental cost) , vehicle intended use,seba power In the absence of a very large num ber of F S S analys es, but train coniguration, and technology state of readiness were guided by a lim ited num ber of F S S runs perform r theed fo considered in estim ating potential technology pathsfor the com m ittee by R icardo, Inc. ( 2 0 0 9 ) , thealuated com m ittee ev eight vehicle classes described earlier. possible seq uences of technology im plem entationdifferfor A s previously stated, an attem pt to perform F every S S on ent classes of vehicles. The developm ent of the tec hnology vehicle m odel with all com binations of technologies is not seq uences shown in F igures 9 . 1 to 9 . 5 also was withdone practicable. S uch a process would necessitate thenalysis a of input from OEM s, Tier 1 suppliers, other published analyses, ( at least) tens of thousands of vehicle and powerrain t technoland the ex pert judgm ent of com m ittee m em velopbers. In de ogy com binations. It would req uire potentially coni dential ing the ranges of fuel consum ption reduction, theom c m ittee engine, transm ission, accessory, and hybrid power raint sysrecogniz ed that the potential reduction for each increm ental tem m aps; vehicle data such as friction as a functi on of vehicle step is highly dependent on the ex tent to which sys tem losses speed; aerodynam ic param eters; and m any others m para eters could have been reduced by previous technologies. These that are either proprietary or would req uire signii cant vehicle pathways attem pt to include such factors as cost-fectiveness ef testing to generate for all of the com binations tha t are possible. ( percent fuel consum ption reduction/ increm ental t) cos , logical In som e published studies, OEM s have supported such seq uencing based upon preex isting technology, techn ical lim ianalyses for a lim ited num ber of vehicles that were chosen tations, and ease of im plem entation ( req uiremor m entsajor f as suficiently representative for discussion of the technology or m inor m anufacturing changes, including productio n line beneits and associated costs. F or ex am ple, S esearch, ierra R considerations) . S ubjective judgm ent by the comee m alsoitt in its report for the A lliance of A utom obile Macturers anuf played a role in the pathway deinition process.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

AP P LICATION OF V EH ICLE TECH NOLOGIES TO V EH SES ICLE CLAS

*Item may be replaced by subsequent technology **Not included in totals F IGU R E 9 . 1

S m all- car pathways with estim fuel ated consum total ption reduction and cost shown.

14 5

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

14 6

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

*Item may be replaced by subsequent technology **Not included in totals F IGU R E 9 . 2 Interm ediate- and large- car andy unitstandard bodtruck pathways with estim ated total fuel consum ption reduction and cost shown.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

AP P LICATION OF V EH ICLE TECH NOLOGIES TO V EH SES ICLE CLAS

14 7

F IGU R E Two9 . 3 seater convertible and coupe, high- perform ance sedan, and unit- body perform ance truck pathwaysh wit estim ated total fuel consum ption reduction and cost shown.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

14 8

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

F IGU R E 9 . 4 Body- on- fram e sm all- truck pathways estim ated with total fuel consum ption reduction and cost shown.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

AP P LICATION OF V EH ICLE TECH NOLOGIES TO V EH SES ICLE CLAS

F IGU R E 9 . 5

L arge- truck pathways with estim l fuelated consum tota ption reduction and cost shown.

14 9

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

15 0

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

A lthough the com m ittee believes that som e potential retho u g h p rep ared in resp o nse to the co mmittee’s ement ostat f duction is possible with each of the technologies considered, task , these data are ap p ro ximate in natu re and assho su ch u ld the ex tent to which a system energy loss can be red uced is no t b e u sed as inp u t to anal y ses w here mou del racy ing acc highly dependent on all of the system interactiveffects, e the is imp o rtant. They are p ro vided here as ro u ates g hthat estim ex tent to which the baseline technology pack age has already can b e u sed in a q u al itative co mp arative sense mp w hen ar- co reduced different categories of energy losses, andthe producing the rel ative co st- b eneits o f sp ark - ig) nitio - rel ated n ( SI tion calibration param eters chosen by each m anufact urer for techno l o g ies that are p o tential candidates fo anal r Fy SS ses. the inal release of each vehicle. Evaluating the energy losses The co mmittee’s estimates can al so b e u sed fo alr aitative q u associated with these technology pathways is discussed later co mp ariso n o f SI- rel ated techno l o g ies to idates o ther cand in this chapter. su ch as l ig ht- du ty diesel o r hy b rid vehicl es. R eview of F igures 9 . 1 through 9 . 5 shows that tainin cer The results show that signiicant reductions in fuel concases ( interm ediate and large cars; unit- body stand ard truck s; sum ption are possible with technologies that are ready al in two- seater convertibles, coupes, and high- performce an sedans; production in U . S . , European, or A sian m arkexets. am F - or unit- body perform ance truck s) the technology pathwa ys are ple, for the interm ediate car, large car, and unibo dy standard the sam e because of the sim ilar base vehicle power train. truck classes, the average reduction in fuel consum ption for H owever, the tradeoffs m ade as a result of varying perforthe S I path is 2 9 percent at a cost of approx im y $ atel 2 ,2 0 0 ; m ance m etrics as these vehicle types go throughirthe product the average reduction for the com pression- ignition ( CI) enevolution would result in different levels of fuel consum ption gine path is 3 8 percent at a cost of approx im ately $ 5 , 9 0 0 ; and im provem ent depending on the speciic vehicle applic ation. the average reduction for the hybrids path is about 4 4 perEach range in potential fuel consum ption reduction is an cent at an average cost of approx im ately $ 6 , 0 general, 0 0 . In attem pt by the com m ittee to estim ate the potential variation diesel engine and hybrid vehicle technology options offer in energy loss reduction that m ight be possible whe n apgreater im provem ent potential com pared to the thway, S I pa plying the technology to different power train and vehicle but at a higher increm ental cost. H owever, as evide nced by pack ages, tak ing into consideration k nown system atures fe the increasingly wide range in estim ated fuel consu m ption that will lik ely be optim iz ed for different classes of vehicles reduction and increm ental cost, actual fuel consum tionpim with different intended uses. A n ex am ple wouldhebebias t provem ent can vary signiicantly depending on an ind ividual inherent in production calibration of light- duty truck s or m anufacturer’s product strategy. F urther, it m that ay be the S U V s where reasonable towing capability is req . uired needs to reduce vehicle fuel consum ption as m andate d by A sim ple, m ultiplicative aggregation of the potenti al recent legislation will result in OEM s im plem enting these fuel consum ption reduction is presented below eachpath technologies in such a way that the beneits fall toward the in F igures 9 . 1 through 9 . 5 as a m eans to roughly tim atees high end of the range. It should be noted that am gonits provithe total potential that m ight be possible. A proba bilistic sions related to fuel econom y, the Energy Independe nce and m ethodology based on the m ean sq uare rule was ed appli S ecurity A ct ( EIS A ) of 2 0 0 7 req uired sm periodic ents asses to estim ate the conidence intervals for the aggrega tion of by the NR C of autom obile vehicle fuel econom y olotechn fuel consum ption im provem ents and costs. A ppendix pro- J gies and their costs. Thus, follow- on NR C com m s will ittee be vides the m athem atical ex planation for this m logy. ethodo responsible for responding to the EIS A m andates, cluding in It assum es that the conidence intervals on each ind ividual the periodic evaluation of costs and fuel consum pti on benestim ate of technology effectiveness or cost are th e sam e. It eits of individual technologies and the com bined im pacts of also assum es that ranges in estim ates are independent of each m ultiple technologies. other and that errors are norm ally distributed. The approach W hen developing the effectiveness num bers, attem pts then m aintains a conidence interval for the aggrega tion of were m ade by the com m ittee to increm entally the adjust the low or high ends of the estim ates that is eq ual to the coneffectiveness num bers of certain technologies thatwould idence intervals estim ated for the individual techn ologies. norm ally be preceded by another technology. This ocess pr The com m ittee assum es that the ranges for the idual indiv allowed the com m ittee to approx im ate the inclusion of the costs and effectiveness represent a 9 0 percent coni dence synergistic effects resulting from the com bination of certain level. A s such, the ranges were increased in techni cal areas technologies that were deem ed to usually be pack age d towhere, in the opinion of the com m ittee, m ore ainty uncert gether. In an attem pt to evaluate the increm ental ffectivee ex isted with initial estim ates. ness num bers for the S I pathway derived by the com ittee, m It should also be noted that when the com bination fo com parisons were conducted using the F S S data the from fuel consum ption im provem ent predictions and associ ated R icardo report prepared for the com m ittee ( R Inc. icardo, , increm ental costs is considered, the probability ops dr to 2 0 0 9 ) , the EP A - provided lum ped param eter varim odel, and 8 1 percent that any actual production technology troducin ous other S A E papers where com binations of technolo gies tion would fall within the ranges bounded by both the fuel were assessed. A com parison to the R icardo data shown is consum ption and cost ranges. This reduction is due to the in F igure 9 . 6 . P ack ages involving CV Ts wered ex be- clude ( m ultiplicative) product of two 9 0 percent probabil ities. Al cause the com m ittee agrees with the EP A ( EP A ) that , 2 0 0 8 b

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45

Ricardo

40

Fuel-Consumption Reduction %

NRC 35 30 25 20 15 10 5

Truck 12

Truck 17

Truck 10

Truck 9

Truck 11

Lg MPV 16

Lg MPV 6b

Lg MPV 4

Sm MPV 15

Sm MPV 5

Sm MPV Z

Sm MPV 2

Lg Car 16

Lg Car 5

Lg Car 4

Lg Car 6a

Std Car 2

Std Car Z

0

Package

F IGU R E NR 9 . 6C estim ates of effectiveness in reducing the fuel consum ption of various light- duty vehicles com dpare with R icardo, Inc. ( 2 0 0 9 ) estim ates based on data obtained with ystem full ssim ulation.

R icardo, Inc. , used an abnorm ally sm all fuel consum ption tion in energy losses, despite consideration givento the total effectiveness value for this type of transm ission. system energy consum ers. Therefore, as another kchec on A s can be seen in F igure 9 . 6 , the pack ages’n-fuel cothe predicted aggregation of potential technologies, the com sum ption reduction results generally follow the rel ative m ittee contracted with EEA to apply its lum pedmpara eter com parisons between the pack ages analyz ed by R o,icard m odeling approach to evaluate the com m ittee’s ates. estim Inc. This is lik ely due to the engineering judgm ent of the S im pliied lum ped param eter m odels of vehicleuse energy m em bers of the com m ittee whose ex perience in train power ( e. g. , S ovran and Bohn, 1 9 8 1 ) provide a maluating eans of ev engineering could be applied to the assessm ent. H ever, ow whether the fuel consum ption beneits estim ate for omc binathe absolute levels of potential im provem ent canryvasigtions of technologies by the m ultiplication m ethods result niicantly between the com m ittee estim ates and do R icar from forcing categories of energy losses ( pum ping nd frica analyses. F urtherm ore, a com parison of the stepstepby- tion) to physically im possible levels. A ppendixrovides K p increm ental estim ates that would result from the plication ap a description of the EEA lum ped param eter m odel well as of single technologies was not conducted. Therefore, it is not as a description of the results in term s of the tra ctive energy possible to determ ine whether the dem onstrated corr elations req uirem ents and the engine eficiency for the S dI diesel an were a result of accurate increm ental estim ates,whether or a test cycles. These results indicate that the results from the com bination of over- and underestim ates resulted a rough in m ultiplication m ethod used here lik ely do not ly great overapprox im ation, where such occurs. state the beneits because this m ethod does not ex plicitly tak e In any case, the R icardo, Inc. , pack ages represent only a into account the theoretical lim its of pum ping loss reduction. subset of the greater num ber of technology com binat ions that F igures 9 . 7 and 9 . 8 show the m odel resultsheversus t would result from proceeding down the entire pathwa y evalucom m ittee estim ates for eight cases ( four forths, S Iand pa ated by the com m ittee. This underscores the im nce porta of four for diesel paths) . The m odel estim ates for rem inc ental using F S S to account for the larger num ber ofology technsynim provem ents are relatively close to those of the omc m ittee, ergies and ensure that system loss reduction is not overstated. with the com m ittee’s estim ates generally ex ceeding those of D ue to the approx im ate nature of the estim ates ncreof i the EEA m odel by a sm all am ount. These com are parisons m ental im provem ents in fuel consum ption, the tee com mmit ade between the average level of the com m ittee’s stim e ates recogniz es the potential to overestim ate the potent ial reducand the EEA data with no range presented. It should also be

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NRC Estimate

35.0

Lumped Parameter Estimate

Fuel-Consumption Reduction %

30.0 25.0 20.0 15.0 10.0 5.0 0.0 Small Cars

F IGU R E 9 . 7 outputs.

Intermediate & Lg Cars

BOF-Small Trucks

BOF-Large Trucks

NR C estim ates of effectiveness nginfuel reduci consum ption in spark - ignition engine pathwa ys com pared to EEA

m odel

NRC Estimate

45.0

Lumped Parameter Estimate

Fuel-Consumption Reduction %

40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 Small Cars

Intermediate & Lg Cars

BOF-Small Trucks

BOF-Large Trucks

F IGU R E NR 9 . 8C estim ates of effectiveness in reducing fuel con sum ption in diesel engine pathways com pared to EEA m odel outputs.

noted that a baseline 4 - speed autom atic was used r both fo the potential levels of energy loss reduction are em plo yed in com m ittee’s and EEA estim ates because these com sons pari both the EEA lum ped param eter approach and thertex pe were conducted prior to the com m ittee’s decisionutiliz to e opinion of the com m ittee m em bers. The EEA m s odel doe the average class transm ission from the 2 0 0 7 st EP dataA te em ploy an algorithm to account for increm entalctions redu in the technology paths. of energy losses, as predicted by an industry- deriv ed set of One m ight conclude that the EEA m odeling does, act,in f eq uations ( see Chapter 8 ) . Therefore, it is not prising sur that suggest that the com m ittee’s estim ates slightly rpredict ove the estim ations are relatively close. the estim ate. H owever, the sam e general m ethod om of - c H owever, the applications of the EEA ’s or the com ttee’s m i parison with k nown production vehicles and estim ng atithe estim ation approach is done without a detailed unde rstanding

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of the actual levels of therm al eficiency of a subj ect vehicle’s engine, the inluence of com bustion cham ber design n the o fuel conversion eficiency, the actual levels of gasex change or frictional losses, and all of the other param ete rs for which additional technologies can be applied to reduce fuel consum ption.This is only possible through a com bination of ex perim ental and analytical analyses, which are essary nec to predict the absolute level of fuel consum ption. S tated another way, in the opinion of the com m , ittee neither the lum ped param eter approaches evaluated y the b com m ittee nor the com m ittee’s aggregated estim deineates the actual level of energy eficiencies and/ or losses of a random ly chosen vehicle with suficient accuracy toallow accurate predictions of future technology introductions. F urtherm ore, this inaccuracy further degrades nasincreasa ing num ber of technologies is em ployed. Therefore, the com m ittee believes that a physics- based, F S m S , binain co tion with ex perim entally generated data, is req duire for such predictions, especially if technology that is not currently in production is considered.

IMPROVEMENTS TO MODELING OF MULTIPLE FUEL ECONOMY TECHNOLOGIES The application of F S S , in which the engine load, hermt odynam ic eficiency, operational losses of energy, dan accessory loads are varied as a function of vehicle operational perform ance, offers the best opportunity to evaluat e the effectiveness of increm ental application of vehiclesystem s in reducing vehicle energy losses, thereby im provin g overall operational cycle eficiency and reducing fuel consum ption. H owever, since different technologies m ay be attem ting to p reduce the sam e type of loss, for instance, pum ping loss, it is necessary to evaluate the contribution of each increm ental technology in reducing the different losses in each step along a potential product im provem ent path. Through the application of increm ental technologies, one at aimt e, and then optim iz ing the predicted overall vehicle perfo rm ance and fuel econom y tradeoffs, it is possible to under stand and

TA BL E 9 . 3

q uantify, at least for the vehicle m odel being eval uated, the interactive or synergistic effects that result. These m ay be positive or negative synergies, as outlined in the R icardo report prepared for this com m ittee ( R icardo,2 Inc. 0 0 , 9 ) and discussed in Chapter 8 of this report. A n ex am f these ple o synergistic effects is presented in Table 9 . 3 . Table 9 . 3 shows that the total im provem ent in confuel sum ption is gained from a com bination of prim neits ary be attributed to a technology pair and a synergistic beneit ( or detrim ent) as a result of the energy losses that are targeted for reduction. If one considers the engine and transm sion is com bination, beneits in reduced pum ping losses occur if a downsiz ed, higher- speciic- power engine is applied. Ational ddi beneits can be gained from a m ore eficient transm sionis with reduced hydraulic losses or reduced friction. H owever, when these two are applied, there are additional beneits that arise from the ability to run the engine at a loweroperating speed for a given power level, thereby increasing the brak e m ean effective pressure in the cylinders and furthe r reducing the pum ping losses. This contributes to the 27 . percent 1 im provem ent outlined in Table 9 . 3 . H owever, m portant it is i to note that the absolute level and relative levels of im provem ent outlined in Table 9 . 3 m ay vary signiicantly, epend-d ing on the application of the sam e technology seqence u to another vehicle application. A s evidenced by the R icardo, Inc. , F S S analyses con ducted for the com m ittee, different vehicle types, with differing intended uses, dem onstrate different opti m iz ationof- perform ance characteristics. Therefore, whenem att pting to estim ate the increm ental beneits from the applic ation of discrete technologies, the vehicle class, intended use, and associated perform ance m etrics m ust be consider ed. F urtherm ore, the positive or negative synergistic ffects e of m ultiple vehicle energy- loss- reducing technologies will vary depending on the vehicle class and intended performance. A s outlined in Chapter 8 of this report, the curren t NH TS A m ethod of applying technologies to vehicles ppliesa them increm entally and individually to each vehicle in the NH TS A database, starting from the ex perim terentally de

F uel Consum ption S ynergy V alues - treefor Technology Inter P airs—R esults for Truck P ack age 1 1

Inter- tree Technology P air Engine–transm ission F inal drive ratio–engine A ggressive shift logic–engine Electric accessories–engine A erodynam ic drag–engine A erodynam ic drag–transm ission A erodynam ic drag–inal drive ratio A erodynam ic drag–electric accessories A ggressive shift logic–aerodynam ic drag

F raction of Total F uel Consum ption Im pact A ttributed to Inter- tree Technology P air ( % ) 6 .6 2 2 .8 1 −1 . 2 8 0 .8 8 0 .4 4 0 .3 6 0 .2 3 0 .2 1 0 .1 4

S ynergy V alue—Im pact on Total F uel Consum ption R eduction from S ynergy of Technology P air ( % ) 2 0 −0 0 0 0 0 0 0

.1 .8 .3 .2 .1 .1 .0 .0 .0

7 8 9 7 3 1 7 6 4

NOTE: The m odeling included three decision trees orfam ilies of technologies, one for engine technolog ies, one for transm ission technologies, and a third for vehicle technologies. The results shown are forTruck P ack age 1 1 ( R icardo, Inc. , 2 0 0 9 )

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m ined value for com bined fuel econom y as dem ed onstrat in The use of such m odels m ay be necessary when evalua ting the EP A vehicle ex haust em ission certiicationss. proce One advanced technologies, such as variable com pression ratio, potential law in this m ethodology results from process the that m ay not be readily available from production ehicles. v in which the lum ped param eter m odel is used toictpred the V ehicle- related data, such as data on frontal area, rolling m agnitude of energy loss reduction through the appl ication resistance, and weight also are req uired input form odeling of discrete technologies on an actual vehicle- by- ve hicle of vehicle perform ance and fuel econom y. H owever, hese t basis. W ithout k nowing the starting point in term of how s data are m ore readily approx im ated based upon sim iied pl m uch the energy losses have been already been reduc ed, physics- based calculations or are published in accordance the ability to accurately project further reductions in such with vehicle certification testing. Therefore, altho ugh system energy losses, and therefore fuel consum n, ptiocan physics- based engine sim ulation m odels are availabl e, the be highly erroneous. use of ex perim ental engine data, as described above , greatly S tated another way, it appears m ost logical to begi n any im proves the accuracy of the m odeling. predictive analysis with actual vehicle ex perim enta l data, if Ex perim ental m ethods used to understand the effects they are available, as is the case with all vehicles certiied of different technologies in an attem pt to reduce ystem s under the EP A Test Car L ist. H owever, withoutngk nowienergy losses have been developed under the U nitedS tates how successful each m anufacturer has been on a vehi cle- byCouncil for A utom otive R esearch ( U S CA R ) gBenchm ark vehicle basis in an ongoing attem pt to reduce suchenergy Consortium . A ctual production vehicles are subjecte d to a losses, it is not possible, without detailed vehicle and power battery of vehicle, engine, and transm ission tests in sufitrain ex perim ental m ethods, to determ ine thetoexwhich tent cient detail to understand how each is applied and how they any such loss can be further reduced, with a reasonable level contribute to the overall perform ance and fuel cons um ption of accuracy, on an actual vehicle m odel. factors in light- duty vehicles. Com bining such exrimpe ental W ith an understanding of the potential errors that will m ethods with F S S m odeling, wherein all sim ariulation v result from the approx im ation m ethod presentede, abov ables and subsystem m aps would be transparent to l interal or other lum ped param eter approaches where insufici ent ested parties ( both the regulatory agencies and autom otive inform ation is k nown about the level of energy loss reducm anufacturers, for ex am ple) , would allow, ininion the op tion that has previously occurred on a particular vehicle, of the com m ittee, the best opportunity to deineechniat the com m ittee proposes an alternative m ethod whereb y the cal baseline against which potential im provem ents ould c potential for fuel consum ption reduction and its as sociated be m ore accurately and openly analyz ed than the cur rent costs can be assessed. This proposed m ethod woulde-d m ethods em ployed. term ine a characteristic vehicle that would be dein ed as a The advantages of such a m ethod include the abilityto reasonable average representative of a class of vehicles. This ex plicitly account for all energy loss categories,the ability representative vehicle, whether real or theoretical, would to directly estim ate fuel consum ption ( as opposed o the t undergo suficient F S S , com bined with ex perimdeterentally percent change in fuel consum ption) , and the abilit y to repm ined and vehicle- class- speciic system m apping, allow to a resent new technologies and com binations of technol ogies. reasonable understanding of the contributory effects of the It also recogniz es the increasingly com m on utiliz ion of at applied technologies in the reduction of energy losses. The F S S m odels by regulatory agencies and other entitie s outreference to a “theoretical” vehicle suggests that if, during side the autom otive industry. F inally, the m ethod roposes p the regulatory process, the NH TS A and the EP Audeconcl a procedure whereby engine and vehicle ex perim ental data that a vehicle m ay be characteriz ed to representclass a that can be obtained without reliance on proprietary data, such m ay not be in production, F S S m odels m ayreated still be c as engine m aps, that have posed a barrier to effect ive utiliusing physics- based vehicle m odels com bined with periex z ation of F S S m odels by non- OEM s in the past. m entally generated engine m aps. The steps in the recom m ended process are as follows : In any full system sim ulation, the engine/ power in/tra vehicle system is deined by input data that are gen erated 1 . D evelop a set of baseline vehicle classes from which a by other physics- based analyses, engineering judgmnt,e characteristic vehicle can be chosen to represent each or ex perim entally or em pirically derived tests. eriEx p class. The vehicle m ay be either real or theoretica l m entally m easured data for engine m aps can incorpor ate and will possess the average attributes of that class as m anufacturer- predeterm ined calibration param that eters determ ined by sales- weighted averages. have tak en into consideration production operational factors 2 . Identify technologies with a potential to reduc e fuel such as k nock - preventing spark tim ing or air/atio fuel r consum ption. adjustm ents, which are used to protect from com ntpone 3 . D eterm ine the applicability of each technology to the tem perature ex trem es. P hysics- based engine mneraps, ge various vehicle classes. ated from engine com bustion m odels, m ay also d, be butuse 4 . Estim ate the technology’s prelim inary im pact fuel on calibration- speciic param eters m ust also be incorpo rated consum ption and cost. into such m odels to achieve best possible predictiv e results.

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15 5

5 . D eterm ine the optim um im plem entation seq uence 9 .2:D ata m ade available to the com m ittee from Finding ( technology pathway) based on cost- effectiveness dan original eq uipm ent m anufacturers and Tier 1 supplie rs and engineering considerations. found in various published studies suggest a very wide range 6 . D ocum ent the cost- effectiveness and engineeringin estim ated increm ental cost that m ak es assessm s of costent judgm ent assum ptions used in step 5 and m ak e this effectiveness very approx im ate. Generally, the com ittee m inform ation part of a widely accessible database. notes that estim ates of cost are always m ore uncert ain than 7 . U tiliz e m odeling software ( F S S ) to ough progress thr estim ates of im pact on fuel consum ption, and tim the esates each technology pathway for each vehicle class to presented here should be considered very uncertain until obtain the inal increm ental effects of adding each m ore detailed studies are com pleted. A s notedapter in Ch3 , technology. estim ates based on teardown cost analysis, currentl y being utiliz ed by the EP A in its regulatory analysis lightfor duty If such a process were adopted as part of a regulatory rulevehicle greenhouse gas em issions standards, should be ex m ak ing procedure, it could be com pleted on 3 -ycles year c panded for developing cost im pact analyses. to allow regulatory agencies suficient lead tim e to integrate the results into future proposed and enacted rules. Finding 9 .3 In: response to the statem ent of task , the com Based on the eight new vehicle classes proposed by the m ittee estim ated possible technology evolution path s for com m ittee, an average vehicle, either real or theor etical, each vehicle class that arise from the average base line vewould be chosen that possessed the average attributes of hicle. A very sim ple, m ultiplicative aggregation potential of the vehicles in that class. It would be of average weight, for reducing fuel consum ption is presented as a m nseato footprint, engine displacem ent, and other character istics. roughly estim ate the total potential that m ight possible. be The resulting vehicle would serve as the baseline for F S S The results from this analysis show that, for the nterm i ediate analysis. This would also allow a very im portant arting st car, large car, and unibody standard truck classes, the averpoint for the vehicle system s from which potential im proveage reduction in fuel consum ption for the S I path s about i m ents could be evaluated. U sing detailed benchmdata, ark 2 9 percent at a cost of approx im ately $ 2 , 2 verage 0 0 ; the a deined levels of energy losses would be used as input into reduction for the CI path is about 3 8 percent at cost a of the sim ulation m odel. The data used to choose the ehicle v approx im ately $ 5 , 9 0 0 ; and the average reduction the hy- for consists of the following speciications available from the brids path is about 4 4 percent at a cost of $ 6 ,H0 0owever, 0 . EP A test car list: unless calibrated m ethods are used to accurately co nsider the synergistic effects of applying several technologies—effects • F ootprint, that m ay reduce the sam e sources of power train and vehicle • W eight, energy losses—these results are ex trem ely approx teimin a Engine ( displacem ent, cylinder count, horsepower, nature and, in the com m ittee’s opinion, shouldbenot used as torq ue) , input to analyses for which m odeling accuracy is im portant. • V alve train coniguration ( OH V , S OH C, D OH In C)general, , the technology tables that present increm ental • V alve event m odulation technology ( V V T, V V Ldata ) ,for percent reduction in fuel consum ption and estim ated • Com bustion technology ( S I, CI, H CCI) , increm ental cost cannot be used in their current fo rm as input • F uel injection m ethod and fuel type ( S EQ , FGD I, I, D into lum ped param eter- type m odels without m oethods ac- t gasoline, diesel) , curately consider the synergistic effects of applying several • A spiration m ethod ( natural, supercharged, charged) turbo , technologies and without signiicant ex pertise in vehicle • Num ber of occupants, technologies to fully understand integration issues. • P ower/ vehicle weight ratio, • Transm ission type and gear ratio spread, Recommendation 9 .1 A: s noted in Chapter 8 , full system • D riveline ( F W D , R W D , A W D ) , and sim ulation ( F S S ) , based on em pirically derived r trainpowe • EP A vehicle class. and vehicle perform ance and fuel consum ption dataaps, m offers what the com m ittee believes is the best avail able m ethod to fully account for system energy lossesd an synerFINDINGS AND RECOMMENDATION gies and to analyz e potential reductions in fuel consum ption Finding 9 .1M: any vehicle and power train technologies that as technologies are introduced into the m ark et. Fanalyses S S reduce fuel consum ption are currently in or enterin g producconducted for the com m ittee show that synergy effec ts betion or are in advanced stages of developm ent in Eu ropean tween differing types of energy- loss- reducing techn ologies or A sian m ark ets where high consum er prices lfor have fue vary greatly from vehicle application to vehicle ap plication. justiied their com m ercializ ation. D ependingintended on the The com m ittee proposes a m ethod whereby F S Ss analyse vehicle use or current state of energy- loss m inimation, iz the are used on class- characteriz ing vehicles, so that synergies application of increm ental technologies will produce varying and effectiveness in im plem enting m ultiple fuel nom eco y levels of fuel consum ption reduction. technologies can be evaluated with what should be greater

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accuracy. This proposed m ethod would determ ine a char6 . D ocum ent the cost- effectiveness and engineering acteristic vehicle that would be deined as a reasonable judgm ent assum ptions used in step 5 and m ak e this average representative of a class of vehicles. Thisrepreseninform ation part of a widely accessible database. tative vehicle, whether real or theoretical, wouldundergo 7 . U tiliz e m odeling software ( F S S ) to ough progress thr suficient F S S , com bined with ex perim entallyned determ i each technology pathway for each vehicle class to and vehicle- class- specific system m apping, to allow a obtain the inal increm ental effects of adding each reasonable understanding of the contributory effects of the technology. technologies applied to reduce vehicle energy losses. D ata developed under the U nited S tates Council for A utom otive If such a process were adopted as part of a regulatory ruleR esearch ( U S CA R ) Benchm ark ing Consortium should m ak be ing procedure, it could be com pleted on 3 -ycles year c considered as a source for such analysis and potentially to allow regulatory agencies suficient lead tim e to integrate ex panded. U nder the U S CA R program , actual n productio the results into future proposed and enacted rules. vehicles are subjected to a battery of vehicle, engine, and transm ission tests in suficient detail to understan d how each BIBLIOGRAPHY candidate technology is applied and how it contributes to EP A ( U . S . Environm ental P rotection A gency) L ight. 2 D0 uty 0 8 Aa. utothe overall perform ance and fuel consum ption ofhtligduty m otive Technology and F uel Econom y Trends: 1 9 ough 7 5 2Thr 0 0 8 . vehicles. Com bining the results of such testing wit h F S S EP A 4 2 0 - R - 0 8 - 0 1 5 . S eptem ber. m odeling, and thereby m ak ing all sim ulationes variabl and EP A . 2 0 0 8 b. EP A S taff Technical R eport: fectiveness Cost andEstim Ef ates subsystem m aps transparent to all interested partie s, would of Technologies U sed to R educe L ight- D uty V arbon ehicleDC iox ide allow the best opportunity to deine a technical baseline Em issions. EP A 4 2 0 - R - 0 8 - 0 0 8 . A nn A rbor, M ich. NH TS A ( National H ighway Trafic S afety A dm n) . inistratio 2 0 0 9 . A verage against which potential im provem ents could be analy z ed fuel econom y standards, passenger cars and lightuck tr s, m odel- year m ore accurately and openly than is the case with th e current 2 0 1 1 : inal rule, R IN 2 1 2 7 A K - 2 9 , D ock 0 0 et 9 -No. 0 0NH 6 2 TS . m ethods em ployed. W ashington, D . C. , M arch 2 3 . The steps in the recom m ended process are as follows : NR C ( National R esearch Council) . 2 0 0 2 . Effectivenes s and Im pact of Corporate A verage F uel Econom y ( CA F E) S tandards. nal A Natio cadem y P ress, W ashington, D . C. 1 . D evelop a set of baseline vehicle classes from which a R icardo, Inc. 2 0 0 8 . A S tudy of P otential essEffectiven of Carbon D iox ide characteristic vehicle can be chosen to represent each R educing V ehicle Technologies. EP A 4 2 0 - R pared - 0 8 for - 0 the 0 4 . P re class. The vehicle m ay be either real or theoretica l U . S . Environm ental P rotection A gency, Contract EP - No. C- 0 6 - 0 0 3 , and will possess the average attributes of that class as W ork A ssignm ent No. 1 - 1 4 . A nn A rbor, M ich. determ ined by sales- weighted averages. R icardo, Inc. 2 0 0 9 . A S tudy of Interaction Between EffectsL ight D uty V ehicle Technologies. P repared for the NR C Come on m Aittessessm ent 2 . Identify technologies with a potential to reduc e fuel of Technologies for Im proving L ight- D uty V ehicle el Econom F u y by consum ption. R icardo Inc. , V an Buren, M ich. , F ebruary 2 7 . 3 . D eterm ine the applicability of each technology to the S ovran, G. , and M . S . Bohn. 1 9 8 1 . F orm ractive ulaeenergy for theret various vehicle classes. q uirem ents of vehicles driving the EP A schedule, E P Saper A 8 1 0 1 8 4 . 4 . Estim ate each technology’s prelim inary im n fuel pact o F ebruary. consum ption and cost. 5 . D eterm ine the optim um im plem entation seq uence ( technology pathway) based on cost- effectiveness dan engineering considerations.

A

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Appendixes

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

A Committee Biographies

na T rev or O . J (NA ones E)Chair , is founder, chairm an, and ing from A ston Technical College and an ordinarytional certiicate in m echanical engineering from L iverpool Technichief ex ecutive oficer ( CEO) of ElectroS onics Mal,edic Inc. cal College. Cleveland S tate U niversity awarded JDones r. an Before that, he was founder, chairm an, and CEO of iom B ec, tributions Incorporated, a biom edical device com pany. H eorwas f honorary doctorate of science and cited him for con in the developm ent of fuel cells and biom edical ices. dev m erly chairm an of the board of Echlin, Incorporated , a supplier of autom otive com ponents, prim arily tofterm the a ark et. T homas W . Asmus ( NA E) is a retired senior research ex D r. J ones is also chairm an and CEO of the Internati onal also D evelopm ent Corporation, a private m anagem ent lt- consuecutive of D aim lerChrysler Corporation. H e hasheld positions at M ead Corporation, as an adjunct facult y m em ber ing com pany that advises autom otive supplier comiespan on of m echanical engineering at the U niversity of Migan, ich strategy and technology. H e was chair, president,nd aCEO ni ( retired) of L ibbey- Owens- F ord Com pany, a large ufac-m an and as a professor of physical chem istry at the Uversity of Guadalajara, in M ex ico. H e has m ore than s3of0 year turer of glass for autom otive and construction appl ications. ex perience and has played a leadership role in nearly all P reviously, he served as vice president of engineer ing in the aspects of internal com bustion engine and fuels res earch A utom otive W orldwide S ector of TR W , Incorporated, nd a and developm ent, focusing m ainly on fuel consumn and ptio as group vice president, Transportation Electronics Group. d was iel iniBefore joining TR W , he was em ployed by GeneralrsM otoex haust em issions reduction. H is entry into the em ( GM ) in m any aerospace and autom otive ex ecutive itions,pos tially based on his back ground in com bustion and issions form ation m echanism s for both gasoline and diesel ngines, e including director of GM P roving Grounds; of thelco D Elece nded pa to tronics D ivision, A utom otive Electronic, and S afety ystem s; but with tim e and circum stances his activities ex include gas ex change processes, controls, lubricati on, m any and director of the GM A dvanced P roduct Engineering Group. types of fault diagnoses, and heat m anagem ent. Newconcept D r. J ones is a life fellow of the Institute of Elec trical and Elecanalysis has becom e routine for D r. A sm us. having Besides tronics Engineers ( IEEE) and has been cited for lea dership in been a m em ber of the NA E, he is a fellow of theand S A E the application of electronics to the autom obile. eHis also a was a recipient of the S oichiro H onda L ecture A recipiward fellow of the S ociety of A utom otive Engineers ( ,Sa fellow A E) ent in 1 9 9 9 . H e has a B. S . in paper science ineering and eng of the British Institution of Electrical Engineers, a fellow of from W estern M ichigan U niversity and an M P. Sh. D . and . a the Engineering S ociety of D etroit, a registeredofessional pr in physical chem istry from W estern M ichiganity. U nivers engineer in W isconsin, and a chartered engineerthe in U nited K ingdom . H e holds m any patents and has lectured writ-and Rodica B aranescu( NA E) is a professor in the College of ten on autom otive safety and electronics. H e isem a m ber of l Enthe National A cadem y of Engineering ( NA E) and m a er for Engineering, D epartm ent of M echanical and Industria gineering, U niversity of Illinois at Chicago. Befor e that, she com m issioner of the National R esearch Council ( NR Com C)was m anager of the fuels, lubricants, and engineoup gr of m ission on Engineering and Technical S ystem s.ones D r.hasJ the International Truck and Engine Corporation, atM elrose served on several other NR C study com m ittees,ding inclu the P ark , Illinois. S he is an internationally sought ter af public Com m ittee for a S trategic Transportation R esearch tudy on S tec H ighway S afety. H e chaired the NA E S teering ee Com mspeak itt er on technical issues related to m obility hnology, environm ental control, fuels, and energy. S he xhastensive e on the Im pact of P roducts L iability L aw on Innovati on and the Com m ittee on R eview of the R esearch P rogram the ofex pertise in diesel engine technology and was elected to the NA E in 2 0 0 1 for research leading to effective nd envia P artnership for a New Generation of V ehicles forx sireviews. ronm entally sensitive diesel and alternative- fuelngines e H e holds a higher national certiicate in electricalengineer15 9

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and leadership in autom otive engineering. S he isfellow a P rospective Beneits of D OE’s Energy Eficiency andossil F of S A E International and was its president in 2000. In 2003 Energy R & D P rogram s, P hase 1 , and is currently m ber a m e she received the Internal Com bustion Engine A ward f the o of the NR C Com m ittee on National Tire Eficiency. H e A m erican S ociety of M echanical Engineering ( A S earned M E) a. bachelor’s degree in m echanical engineerin g from D r. Baranescu received her M . S . and P h. D n. m degrees e- i W orcester P olytechnic Institute and is a doctoral andidate c chanical engineering in 1 9 6 1 and 1 9 7 0, respectively , from in transportation technology and policy at the U niv ersity of the P olitechnica U niversity in Bucharest, R om where ania, California, D avis. she served as assistant professor ( 1 9 6 4- 1 9 6urer 8 ) , lect ( 1 9 7 0- 1 9 7 4) , and associate professor ( 1 9 7 4- 1 9 7D 8 av ) . id G reene is a corporate fellow at the Oak R idge National L aboratory ( OR NL ) . H e has spent m ore thanre2 0 years J ay B aron is president of the Center for A utom otive R e- searching transportation and energy policy issues. H is research search ( CA R ) and the director of its M anufacturing, Engiinterests include energy dem and m odeling, econom analysis ic neering and Technology Group. D r. Baron’s recent research of petroleum dependence, m odeling m ark et responses to has focused on developing new m ethods for the analy sis and advanced transportation technologies and alternative—fuels, validation of sheet m etal processes, including die m ak ing, econom ic analysis of policies to m itigate greenhous e gas em istool and die tryout, and sheet m etal assem bly proce sses. sions from transportation, and developing theory danm ethods H e also developed functional build procedures thatresult for m easuring the sustainability of transportationsystem s. in lower tooling costs and shorter developm ent leadtim es, A fter joining OR NL in 1 9 7 7 , he founded thetation Transpor while im proving q uality—particularly with sheet m al aset Energy Group in 1 9 8 0 and in 1 9 8 7 established ansporthe Tr sem blies. H e also has been researching new technolo gies tation R esearch S ection. D r. Greene spent 1 9 98 88 9 toin1 in the auto industry, including look ing at body sho p design W ashington, D . C. , as a senior research analyst he Ofice in t of and lex ibility and evaluating the m anufacturing cap ability D om estic and International Energy P olicy, at the partm D e ent of evolving technologies. H e recently com pletedestigainv of Energy ( D OE) . H e has published m ore than icles 1 5 0 art tions on state- of- the- art tailor- welded blank techn ologies, in professional journals, written contributions to book s and the econom ics of weld- bond adhesives, and the analy sis of technical reports, and given congressional testim yonon transcar door q uality and construction m ethods. Before ecom b portation and energy issues. F rom 1 9 9 7 to 2Greene 0 0 0 D r. ing irst the director of m anufacturing system s at A CR and served as the irst editor- in- chief of theJ o u rnal o f Transp o rtathen president, D r. Baron was the m anager of m cturing anufa tio n and Statistics , the only scholarly periodical published by system s at the Ofice for the S tudy of A utom otive ansporTr the U . S . D epartm ent of Transportation. H eserves currently tation at the U niversity of M ichigan Transportation R esearch on the editorial boards of Transp o rtatio n R esearch , Energ D y Institute. H e also work ed for V olk swagen of A m n erica P io l,icy Transp o rtatio n Q u ,arterl and ythe J o u rnal o f Transq uality assurance and as staff engineer and projectm anager p o rtatio n and Statistics . A ctive in the Transportation R esearch at the Industrial Technology Institute in A nn A rbor and at the Board ( TR B) and the NR C, D r. Greene has served everal on s R ensselaer P olytechnic Institute’s Center for M acturing anuf standing and ad hoc com m ittees. H e is past chairm and an P roductivity in Troy, New Y ork . D r. Baron holds h. D a .P m em ber em eritus of TR B’s Energy Com m ittee, chair was past and a m aster’s degree in industrial and operations engineerof the S ection on Environm ental and Energy Concerns , and ing from the U niversity of M ichigan and an M rom . B. A . was f a recipient of TR B’s P yk e J ohnson A ward. eene D r. Gr R ensselaer P olytechnic Institute. received a B. A . degree from Colum bia U niversity 1 9 7in1 , an M . A . from the U niversity of Oregon in 1 a9P 7h.3D, and . D av id Friedman is the research director of the Clean in geography and environm ental engineering from Jthe ohns V ehicles P rogram of the U nion of Concerned Sstscienti H opk ins U niversity in 1 9 7 8 . ( U CS ) , W ashington, D . C. H e is the author r of or coautho m ore than 3 0 technical papers and reports on advanc em ents L inos J acov ides ( NA E) recently retired as director, D elphi in conventional, fuel cell, and hybrid electric vehicles and R esearch L abs, a position he held from 1 9 9 8. to 2 0 0 7 alternative energy sources with an em phasis on clea n and efD r. J acovides joined General M otors R esearch and vel- D e icient technologies. Before joining U CS in 2 0 0work 1 , ed he opm ent in 1 9 6 7 and becam e departm ent head ical of electr for the U niversity of California, D avis, in the fuel cell vehicle engineering in 1 9 8 5 . H e is a fellow of the IEEE. s areasHofi m odeling program , developing sim ulation toolsaluate to ev research were the interactions between power electronics and fuel cell technology for autom otive applications. eHwork ed electrical m achines in electric vehicles and locomtives. o H e there on U niversity of California’s F utureCar team to build a later transitioned to D elphi with a group of resear chers from hybrid electric fam ily car that doubled its fuel ec onom y. H e GM to set up the D elphi R esearch L aboratories. eceived H er also once work ed at A rthur D . L ittle researching el cell, fu a B. S . in electrical engineering and a m aster’smin achine battery electric, and hybrid electric vehicle technologies, as theory from the U niversity of Glasgow, S cotland. received H e well as photovoltaics. H e served as a m em ber of NRtheC a P h. D . in generator control system s from the ialIm Col-per P anel on the Beneits of F uel Cell R & D of the Com tee on m itlege, U niversity of L ondon, in 1 9 6 5 .

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

AP P ENDIX A

16 1

Com pression Ignition Engine S ystem s Group at the werP o J ohn H . J ohnson is a presidential professor em eritus in train S ystem s R esearch L aboratory. H e alsoosition held a p the D epartm ent of M echanical Engineering- Engineerin g at the Institut F rancais du P etrôle, A pplications ivision, D M echanics at M ichigan Technological U niversity ( M TU ) and mhas ately approx i a fellow of the S A E and the A S M E. H is ex ans perience a spR ueil- M alm aison, in F rance. D r. K rieger 3 5 years of research and developm ent ex perience internal in wide range of analysis and ex perim ental work onanced adv com bustion engines, especially diesel engines andom c busengine concepts, diesel and other internal engine em issions tion. H e holds approx im ately 1 0 patents related enginetoand studies, fuel system s, and engine sim ulation. Hs previe wa hairc ously project engineer at the U . S . A rm y Tank tive A utomemo issions control technologies. H e served as viceand chair of the D iesel Engine Com m ittee, S A asE.a H e h Center, and chief engineer in applied engine research at the B. S . and a P h. D . in m echanical engineering from U ni- the International H arvester Com pany before joining the M TU versity of W isconsin- M adison. m echanical engineering faculty. H e served as chairm an of the M TU m echanical engineering and engineering anm ech is president, chief ex ecutive oficer, and ics departm ent from 1 9 8 6 to 1 9 9 3 . H emhasany servedGonary W . Rogers sole director, F EV , Inc. H is previous positions luded inc com m ittees related to engine technology, enginessions, em i , and and health effects—for ex am ple, com m ittees A of the E, Sthe director, P ower P lant Engineering S ervices D ivision senior analytical engineer, F ailure A nalysis A ates, ssoci NR C, the Com bustion Institute, the H ealth Effects nstitute, I Inc. ; design developm ent engineer, Garrett Turbine Engine and the Environm ental P rotection A gency—and consult s to Com pany; and Ex ploration Geophysicist, S hell Oil m Co a num ber of governm ent and private sector instituti ons. In desiand particular, he served on m any NR C com m ittees, dinginclu pany. H e has ex tensive ex perience in research,gn, ent of advanced engine and powertrain syste m s, the Com m ittee on F uel Econom y of A utom obiles ght and Ldevelopm i including hom ogeneous and direct- injected gasoline enTruck s, the Com m ittee on A dvanced A utom otive lo- Techno gines, high- speed direction injection passenger cardiesel gies P lan, the Com m ittee on the Im pact and eness Effectiv of s Corporate A verage F uel Econom y ( CA F E) S tandards, d the anengines, heavy- duty diesel engines, hybrid vehicleystemeas, gas turbines, pum ps, and com pressors. H idese prov Com m ittee to A ssess F uel Econom y for M edium vy- and H corporate leadership for a m ultinational research,design, D uty V ehicles. H e chaired the NR C Com m ittee ew of on R evi and developm ent organiz ation specializ ing in engine s and D OE’s Ofice of H eavy V ehicle Technologies and the R C N energy system s. H e is a m em ber of the S A visor E, istoan ad Com m ittee on R eview of theCentury 2 1 st Truck partnership. avyon he H e received his P h. D . in m echanical engineering m the fro the D efense A dvanced R esearch P rojects A gency fuel engines, and sits on the advisory board to the College U niversity of W isconsin. of Engineering and Com puter S cience, Oak land Usity, niver R ofCthe N J ohn G . K assak( NA ian E) is professor of electrical en- R ochester, M ichigan. H e served as a m em ber Com m ittee on R eview of D OE’s Ofice of H eavy V ehicle gineering and director of the M assachusetts Institu te of Technologies P rogram , the NR C Com m ittee onc-the Effe Technology’s ( M IT’s) L aboratory for Electrom c agneti and tiveness and Im pact of Corporate A verage F uel Econo m y Electronic S ystem s. H is ex pertise is in the electronics use of ( CA F E) S tandards, and the NR C P anel on Beneits OE’s of D for the control and conversion of electrical energy, indusL ight- D uty H ybrid V ehicle R & D P rogramntly. H e also rec trial and utility applications of power electronics, electronic supported the D epartm ent of Transportation’s Nation al m anufacturing technologies, and autom otive electric al and H ighway Trafic S afety A dm inistration by conducting a peer electronic system s. Before joining the M IT faculty, he served review of the NH TS A CA F E M odel. H e has a B. S . M in the U . S . Navy. D r. K assak ian is on thedirectors boards of from Northern A riz ona U niversity. of a num ber of com panies and has held num eroustions posi with the IEEE, including founding president of the IEEE ( NA E) is the Class of 1 9 3 5 P rofessor of P ower Electronics S ociety. H e is a m em ber ofE,thea NA Rob ert F. Saw yer Energy Em eritus at the U niversity of California,rkBeeley. fellow of the IEEE, and a recipient of the IEEE’s William airasofch E. Newell A ward for Outstanding A chievem ents inerP ow H e is a m em ber of the NA E and recently served sitions po Electronics ( 1 9 8 7 ) , the IEEE Centennial M edal ) , and ( 1 9 8 the 4 California A ir R esources Board. H is previous include research engineer and chief, L iq uid S ystem A nalys the IEEE P ower Electronics S ociety’s D istinguished S ervice sis, U m. S . A ir F orce R ock et P ropulsion Lem aboratory; ber of m A ward ( 1 9 9 8 ) . H e has served on a num ber ofitNR C com California ber, tees, including the Com m ittee on R eview of thearch R ese the research staff, P rinceton U niversity; m em A ir R esources Board; and chair, Energy and R esource s P rogram of the P artnership for a New Generation V ofehicles e ispresia and the R eview of the F reedom CA R and F uel P R roesearchGroup, U niversity of California, Berk eley. H past incl com gram . H e has an S c. D . in electrical engineering m Mfro IT. dent of the Com bustion Institute. H is researchudes bustion chem istry, pollutant form ation and control, engine em issions, tox ic waste incineration, alternative els,fu and Roger B . K rieger is currently an adjunct professor at the regulatory policy. D r. S awyer served on num erous tional Na engine research center of the U niversity of W iscons in, m itte M adison. Before that, he was laboratory group m er, anag R esearch Council com m ittees, including the Come for

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the Evaluation of the Congestion M itigation and A Qir uality Im provem ent P rogram , the Com m ittee toAR ’seview EP M obile S ource Em issions F actor OBIL ( ME) M odel, and the Com m ittee on A diabatic D iesel Technology, amers.ong oth H e holds a B. S . and an M . S . ( m echanical )engineering from S tanford U niversity and an M . A . ( aeronautical eering) engin and a P h. D . ( aerospace science) from P rinceton ersity. U niv

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

B Statement of Task

The com m ittee form ed to carry out this study will ro- p vide updated estim ates of the cost and potential ef iciency im provem ents of technologies that m ight be em over ployed the nex t 1 5 years to increase the fuel econom yarious of v light- duty vehicle classes. S peciically, the com m all: ittee sh

cycle sim ulation, based on detailed vehicle engineering characteristics (e. g, .including engine m aps, transm ission shift points, etc. ) . Check the m odels against current, k nown fuel oecon m y ex am ples and select one of each type to perform the analyses of the effects of the technologies in 1 and 2 above.

1 . R eassess the technologies analyz ed in Chapter of the 3 NR C report,Imp act and Effectiveness o f Co rp o rate Averag e F u el Eco no my ( CAF E) (Standards 2 0 0 2 ), for eficacy, cost, and applicability to the classesof 4 . D evelop a set of cost/ potential eficiency imve-pro vehicles considered in that report. In addition, techm ent curves, as in Chapter 3 of the 2 0 0 2 NR, C report nologies that were noted but not analyz ed in depthin that is guided by the following q uestion: “W hatthe is that report, including direct injection engines, diesel estim ated cost and potential fuel econom y beneit of engines, and hybrid electric vehicles, shall be assessed technologies that could be applied to im prove theuel f for eficacy, cost and applicability. W eight and pow er econom y of future passenger vehicles, given the con reductions also shall be included, though consideration straints im posed by vehicle perform ance, functional of weight reductions should be lim ited to advances ity, safety and em ission regulations? ” The ten vehi cle in structural design and lightweight m aterials. The classes considered in the 2 0 0 2 report shall beyz anal ed, assessm ents shall include the effects of “technolog y including im portant variants such as different engi ne seq uencing”—in what order m anufacturers m ight siz es ( e. g. , 6 and 8 cylinders) . M ost analyses l be shal conceivably incorporate fuel econom y technologies, perform ed with the lum ped param eter m odel, but sufiand how such ordering affects technology cost and cient cases to ensure overall accuracy shall be check ed applicability. with the engine m apping m odel. 2 . Estim ate the eficacy, cost, and applicability f emo erg5 . D eine and docum ent the speciic m ethodology( ies) ing fuel econom y technologies that m ight be em ployed and inputs used to estim ate the increm ental costs nd a over the nex t 1 5 years. The assessm ents shalldeinclu beneits of the fuel econom y technologies chosen by the effects of technology seq uencing as deined in 1( ) the com m ittee, including the m ethods used to accoun t above. for variations in vehicle characteristics ( e. g. , zsie, 3 . Identify and assess leading com puter m odels for weight, engine characteristics) and to account forthe projecting vehicle fuel econom y as a function of ad diseq uential application of technologies. U se low rts cha tional technology. These m odels would include both: or sim ilar m ethods to docum ent seq uencing upon which the com m ittee’s estim ates of increm ental s cost • L um ped param eter ( or P artial D iscrete Aa- pprox im and beneits are based. A lthough m ethodologies vary, tion) type m odels, where interactions am ong techthe com m ittee’s report should detail all of itsculacal nologies are represented using energy partitioning tion m ethodology( ies) , even those as basic as sim e pl and/ or scalar adjustm ent factors ( also k nown as m athem atical relationships ( if used) and as com plex synergy factors) , and as structural representations, such as decision trees ( if • F ull vehicle sim ulation, in which such interac tions used) . It should do so to levels of speciicity, cla rity and are analyz ed using ex plicit drive cycle and engine com pleteness suficient for im plem entation and inte16 3

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gration into m odels that project the fuel econom a-y c The com m ittee’s analysis and m ethodologies will be pability of vehicles, leets and m anufacturers, incl uddocum ented in two NR C- approved reports. A n interim report ing leets speciied at the level of individual vehicle will discuss the technologies to be analyz ed, the lasses c of m odels, engines, and transm issions. The report should vehicles which m ay em ploy them , the estim ated vem im ent pro also provide and docum ent estim ates of all inputtada in fuel econom y that m ay result, and the m odels t will thabe req uired for im plem entation of these m ethodologies.used for analysis. The inal report will include the detailed 6 . A ssess how ongoing changes to m anufacturers’ fresh re speciications for the m ethodologies used and the sults re of and redesign cycles for vehicle m odels affect then-i the m odeling, and will m ak e use of the input from he interim t corporation of new fuel- econom y technologies. report and any new inform ation that is available.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

C List of Presentations at Public Committee Meetings

WASHINGTON, D.C., SEPTEMBER 10-11, 2007

M ark D aroux , S tratum Technologies, LithiuInc. m Io , n P ho sp hate B atteries fo r Tractio n Ap p l icatio n J ulie A braham National , H ighway Trafic S afety Tien D uong, U . S . D epartm ent of Statu Energy, so f A dm inistration, F u el Eco no my Techno l o g y Stu dy El ectrical Energ y Sto rag e Techno l o g ies W illiam Charm ley, EP A Ofice of Transportation ir and A M ichel F orissier, V Faleo, u el Eco no my So l u tio ns Q uality representative,Greenho u se Gases and Lig htBart R iley, A 1 2 3 S A12 ystem 3 Sy s, stems B attery Du ty V ehicl es Techno l o g ies Coralie Cooper, Northeast S tates for Coordinated A r i U se M anagem Technical ent, F easib il ity and Co sts Asso ciated w ith R edu cing P asseng er Car GH G WASHINGTON, D.C., NOVEMBER 27-28, 2007 Emissio ns K halil A m ine, A rgonne National L aboratory, Advanced J ohn Germ an, U S A Advanced H onda, Techno l o g ies, H ig h P o w er Chemistries fo r H EV Ap p l icatio ns Diesel s, and H y b rids P aul Blum berg, Ethanol Boosting S ystem s,Ethano L L C, l D an H ancock , GM P owertrain, Assessing P o w ertrain F u el Tu rb o B o o st fo r Gaso l ine Eng ines: Diesel and H y b Eco no my Eq u ival ent Eficiency at an Affo rdab l e Co st J ohn H eywood, M assachusetts Institute of Technology , F rank F odal, Chrysler LF Lu C, el Eco no my / F u el s Chal l eng es in Estimating F u tu re V ehicl e F u el D avid Geanacopoulos, V olk swagen of A m erica, Inc. , Co nsu mp tio n Diesel Techno l o g y fo r V W A ym eric R ousseau, A rgonne National L aboratory, J ohannes R uger, Bosch, Increasing F u el Eco no my : Desig ning Advanced V ehicl e P o w ertrains U sing P SAT Co ntrib u tio n o f B o sch to R each F u tu re Go al s W olfgang S tütz , BM W of North F A umel erica, Eco no my R obert W im m er and S hunsuk e F ushik To i,y Toyota, o ta o f B MW Diesel V ehicl es H y b rid P ro g ram

WASHINGTON, D.C., SEPTEMBER 27, 2007

WASHINGTON, D.C., JANUARY 24-25, 2008

K . G. D uleep, Energy and Environm ental A nalysis, ., Inc S teve A lbu, California A ir R esources Board, AR B Ap p ro aches to Mo del ing V ehicl e F u el Eco no my P ersp ective o n V ehicl e Techno l o g y Co stsgfo r R edu ci K evin Green, The V olpe Center, CAF E Co mp l iance and Greenho u se Gases Effects Mo del ing Sy stem W ynn Bussm an, Consultant, Stu dy o f Indu stry - Averag e M arc W isem an, R icardo, P o Inc. tential , Ap p ro aches Mark - u p F acto rs U sed to Estimate R etail P rice to Mo del ing F u el Eco no my Techno l o g ies: Eng ine Eq u ival ents ( R P E) Simu l atio n Mo del ing Cap ab il ities and Co st Anal y sis K . G. D uleep, Energy and Environm ental A nalysis, ., Inc Cap ab il ities Anal y sis o f Techno l o g y Co st and R etail P rice K evin M cM ahon, M artecVGroup, ariab l e Co sts o f F u el Eco no my Techno l o g ies WASHINGTON, D.C., OCTOBER 25-26, 2007 J am es L yons, S ierra R esearch, Techno Inc. ,l o g y and R etail M anahem A nderm an, A dvanced A utom otive Batteries, P rice Imp l icatio ns o f Mo re String ent CAF E Standards Lithiu m- Io n B atteries fo r H y b rid El ectric V ehicl es: B ased o n V ehicl e Simu l atio n Mo del ing Op p o rtu nities and Chal l eng es 16 5

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

16 6

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

WASHINGTON, D.C., FEBRUARY 25-26, 2008

WASHINGTON, D.C., SEPTEMBER 9-10, 2008

J ulie A braham National , H ighway Trafic S afety S usan Y ester, Chrysler, Op p o rtu nities fo r R edu cing V ehicl e A dm inistration, U p date fro m NH TSA o n R eg u l ato ry Mass Activities and Other Anal y sis J oseph K ubish, M anufacturers of Em issions, Control Eq uipm ent A ssociation, Aftertreatment Techno l o g ies and Strateg ies fo r Lig ht Du ty V ehicl es w iths Emp hasi WASHINGTON, D.C., MARCH 31-APRIL 1, 2008 o n NOx and P articu l ates D avid H augen and M att Brustar,Ofice EP Aof F rank F roncz ak , U niversity of W Hisconsin, y drau l ic Transportation and A ir Q uality, Discu ssio n o f EP A’s H y b rid V ehicl e Mo del ing o f F u el Eco no my J ohn K argul, EP A Clean A utom otive Technology m P, rogra K . G. D uleep, Energy and Environm ental A nalysis, ., Inc EP A’s H y drau l ic H y b rid P ro g ram Assessment o f Co sts and F u el Eco no my B eneits

WASHINGTON, D.C., MARCH 16-18, 2009 WASHINGTON, D.C., JUNE 3-4, 2008

EP A Ofice of Transportation and A ir Q uality, U p date fro m M ichael Bull, A lum inum A ssociation, Op p o rtu nities fo r EP A o n Anal y sis o f R P E and Sep arate Ong o ing Wo rk R edu cing V ehicl e Mass o n Estimates o f Anal y sis o f Direct Manu factu ring Bruce M oor, D elphi Electronics and S afety, P o w er Co sts o f Techno l o g ies El ectro nics Sy stems So l u tio ns fo r H EV Architectu res H uang- Y ee Iu, H ymH otion, y mo tio n P l u g - in H y b rid V ehicl e

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

D Select Acronyms

A W D BM EP BOM BS F C CA F E CD P F CI CO2 CR CV V L D D D D D D D D D

CP CT I IS I OC OH C OT P F V V L

E8 5 EA CC ECU EEA EGR EP A EU EV O F F F F F F

A M E C E S S TP W D

all- wheel drive brak e m ean effective pressure bill of m aterials brak e speciic fuel consum ption corporate average fuel econom y catalyz ed diesel particulate ilter com pression ignition carbon diox ide com pression ratio continuously variable valve lift dual cam phasing dual- clutch transm ission direct injection direct injection spark ignition diesel ox idation catalyst dual overhead cam U . S . D epartm ent of Transportation diesel particulate ilter discrete variable valve lift

GD I GH G GM H H H H

C hydrocarbon CCI hom ogeneous- charge com pression ignition EV hybrid- electric vehicle W F ET highway fuel econom y test schedule ( or highway cycle)

I4 IC ICP IV C L L L L L L L

gasoline direct injection greenhouse gas General M otors Com pany

BL D V EV NT P TC V L

inline four- cylinder engine internal com bustion intak e- cam phasing intak e- valve closing low- viscosity lubricants light- duty vehicle low- em issions vehicle lean NO x traps low pressure low- tem perature com bustion low- viscosity lubricant

8 5 percent ethanol M BT m ax im um brak e torq ue electric accessories M P F I m ultipoint fuel injection engine control unit m pg m iles per gallon Energy and Environm ental A nalysis, Inc. M S R P m anufacturer’s suggested retail price ex haust gas recirculation U . S . Environm ental P rotection A gency NA North A m erican European U nion NES CCA F Northeast S tates Center for a Clean Aureir F ut ex haust valve opening NH TS A National H ighway and Trafic S afety A dm inistration fatty acid m ethyl ester NOx nitrous ox ides fuel consum ption NS C NO x storage and reduction catalyst fuel econom y NR C National R esearch Council full system sim ulation NV H noise, vibration, and harshness F ederal Test P rocedure four- wheel drive OBD on- board diagnostics 16 7

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

16 8 OEM OH V P P P P P P

CCI D A F I GM H EV M

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

original eq uipm ent m anufacturer overhead valve prem ix ed charge com pression ignition partial discrete approx im ation port fuel injection platinum group m etal plug- in hybrid electric vehicle particulate m atter

R & D R P E R W D

research and developm ent retail price eq uivalent rear- wheel drive

S A E

S ociety of A utom otive Engineers

S S S S S S

CR GD I I OC OH C U V

U D D S U L EV V V V V V

6 EL EM GT V L

selective catalytic reduction stoichiom etric gasoline direct injection spark ignition state of charge single overhead cam sport utility vehicle urban dynam om eter driving schedule ultralow- em issions vehicle six cylinder V engine valve event and lift valve- event m odulation variable geom etry turbochargers variable valve lift

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

E Comparison of Fuel Consumption and Fuel Economy

change in fuel consum ption of only 1 . 2 5 gal/ 1( 50 00 perm i F igure E. 1 shows the relationship between fuel cons um pcent decrease in F C) , as shown by the lines on the F C vs. F E tion ( F C) and fuel econom y ( F E) , includingethe of the slop curve in F igure E. 1 . In going from 1 5 to 1 ere 9 m is an pg, th curve that relates them ( J ohnson, 2009 The) slope, . which approx im ate 1 . 2 5 gal/ 1 0 0 m ile change inption. fuel consum is negative, and the shape of this relationship areim portant. The nonlinear relationship between fuel consum ptionand The slope indicates the change in F C relative to achange in fuel econom y gives signiicantly m ore weight to lowe r fuel F E—e. g. , when the m agnitude of the slope is high, uch as s econom y vehicles ( 1 5 - 4 0 m pg—i. e. , 6 . 5i)- than 2 . 5 gal/ 1 0 0 at 1 0 m pg, there is large change in F C for a change sm allin to those greater than 4 0 m pg. Going beyond 4 0here m ispg t F E. A t 5 0 m pg, however, there is little change E since in F a perception that fuel eficiency is im proving faster than th e the m agnitude of the slope is very low and approach ing actual change in fuel consum ption. F or a leet that contains a z ero as indicated by the right- hand slope scale onF iglarge num ber of vehicles in the 1 5 - 3 5 m pgerange, vehicles th ure E. 1 . F uel consum ption decreases slowly after m 4 pg 0 with a fuel econom y greater than 4 0 m pg contribute only a since the slope ( lower curve and right- hand scale)of the omecon y, fuel consum ption versus fuel econom y ( F igure E. urve 1 ) c sm all am ount to the weighted average CA F E fuel 1 than 5 - to approaches z ero. The slope rapidly decreases past 04 m pg assum ing that there are fewer 4 0 - m pg vehicles 3 5 - m pg vehicles. since it varies as the inverse of the F E sq uared,hich w then F uel consum ption difference is also the m etric dethat results in a sm all decrease in F C for large F Eeases. incr This term ines the yearly fuel savings in going from ven a gi fuel fact is very im portant since fuel consum ption ise m th etric 1 in in CA F E. F urtherm ore, the harm onic average the CA F E econom y vehicle to a higher fuel econom y vehicle: standards is determ ined as the sales- weighted avera ge of Y early fuel savings = the fuel consum ption for the urban and highway sche dules yearly m iles driven × ( F1 −CF C ( E. 1 ) converted into fuel econom y. F igure 2 . 2 was derived from 2) / 1 0 0 F igures 2 . 1 and E. 1 to show how the share ofonsum fuel c pwhere F C tion decrease is related to percent increase of fuel econom 2y. 1 = fuel consum ption of ex isting vehicle, gal/ 1 0 0 m i, and F2 =C fuel consum ption of new vehicle, gal/ 1 0 0 m i. The curve in F igure 2 . 2 is independent of the value of fuel The am ount of fuel saved in going from 1 4 to 1 for 6 m pg econom y and is calculated by the eq uation in footno te 2 . hesavings sam e is asta F or ex am ple, the fuel consum ption is 2 . 5 gal/ at 1 0 01 2m, 0i 0 0 m iles per year is 1 0 7 gal. This change from 3 5 4 0 m pg and 1 . 2 5 gal/ 1 0 0 m i at 8 0 m mpg,pgwhich is a 4in0fuel econom y for another vehicle in going to 5 0 . 8 m pg. Eq uation E. 1 and this ex am ow plehow again sh change in fuel econom y ( 1 0 0 percent increase in and F aE) im portant fuel consum ption is to judging yearly l fue savings. n

∑1 Nn arm onic average weighted CA F E = n 1 1 ∑ 1 N1 FE +  + N n FE REFERENCE n 1 where Nn = num ber of vehicles in class n; F E n n = fuel econom y of class J ohnson, J . 2 0 0 9 . F uel consum ption and fuel . Peconom resentation y to vehicles; andn = num ber of separate classes of vehicles. the National R esearch Council Com m ittee to A ssess uel Econom F y 2 If F E= ( F –EF E) / F E where F E f 2 1 1 and F C f = ( F1 −CF C 2) / F 2 C 1 and F C 1 Technologies for M edium - and H eavy- D uty V pril ehicles, 7 , DA ear= F E and F C for vehicle baseline and2 FandE F C 2 = F E and F C for vehicle born, M ich. with advanced technology, then, F f C = F f /E( Ff +E 1 ) wheref F= Efractional change in fuel econom y and Ff =C fractional change in fuel consum ption. This eq uation can be used for any change in F E orCFto calculate the values shown in F igure 2 . 2 . A lso, E( 1− F C f = F f /C f) and % F C = 1 f,0 0 F C % F E = 1 f0. . 0 F E 1H

16 9

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

17 0

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

F IGU R E E. 1 F uel consum ption ( F C) versusyfuel ( F econom E) and slope of F C/ F E curve ( two curves and different two scales) . O S U R CE: J ohnson ( 2 0 0 9 ) . R eprinted with perm ission.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

F Review of Estimate of Retail Price Equivalent Markup Factors

V yas et al. ( 2000) of A rgonne National L aboratory ( A NL ) costs is sim ilar although a bit higher: 2 . 1 4 (FTable . 3 ) . To get com pared their own m ark up factors to estim ates loped deve an idea of the m ark up over outsourced com ponentts,cos the by Energy and Environm ental A nalysis, Inc. ( EEA d ) anA NL analysts again assum ed that the supplier would bear Borroni- Bird. Two different m ark up factors were pared: com the costs of warranty, R & D engineering, and depreci ation ( 1 ) the m ark up over direct m anufacturing ( variable) costs and am ortiz ation. S ince EEA m ethods do not separate warfor com ponents produced in house and ( 2 ) the m for ark up ranty costs from m anufacturing overhead, V yas . (et2al0 0 0 ) com ponents purchased fully m anufactured from outsid e assum ed that warranty costs m ade up half of the rhead ove suppliers. In the A NL analysis, costs of m anufactur e include costs. W ith those assum ptions they obtained a mp facark u m aterials, assem bly labor, and other m anufacturing costs but tor of 1 0 0 / ( 3 3 . 6 + 6 . 5 + 6 . 5 + 16 0. .This 3 /2 + 1 2 not depreciation, am ortiz ation, warranty, or R & d engiD an leaves only a bit m ore than 5 percent of the total retail price neering ( Table F . 1 ) . Other costs borne by thenal origi eq uipeq uivalent ( R P E) for the costs of integrating com nents po m ent m anufacturer ( OEM ) are corporate overhead, eits ben into the overall vehicle design, assem bly, and othe r OEM ( retirem ent and health care) , and distribution, kmeting, ar and assem bly costs. dealer costs, including dealer proits. The A NL m em orandum concludes that all three sources Because the cost categories used by Borroni- Bird and would result in very sim ilar m ark up factors ( Table F .4 ) . EEA differed from those used by the A NL study, x act an e H owever, for m ark ups over Tier 1 supplier costs, e A NL th com parison is not possible ( Table F . 2 ) . W hile et al. V yas decision on how to allocate the costs has a lot to do with the ( 2 0 0 0 ) concluded that the three sets of estimereates q uite w sim ilarities. A less generous allocation of warrant y, assem close, the different deinitions cloud the issue. Fr oex am ple, bly, and m anufacturing overhead costs to suppliers would V yas et al. ( 2 0 0 0 ) assum ed that half of the hown costs—s result in higher m ark up factors for outsourced com onents. p by Borroni- Bird as transportation/ warranty; am ortiz ation D espite these am biguities, the A NL com parison ns that reaso and depreciation; engineering R & D , pension and th,heal the m ark up for in- house- m ade com ponents would out be ab advertising, and overhead—would be borne by the outside twofold rather than the 1 . 5 - fold m ark up for com nts pone supplier. In their own estim ates they allocate all warranty, purchased from Tier 1 suppliers. R & D / engineering, and depreciation and am ortiz costsation A m ark up factor of 1 . 5 was used by NH TS A ( D OT to the supplier. Clearly, even com ponents purchased fully NH TS A , 2 0 0 9 , p. 1 7 3 ) in its inal fuelfor econom y rule m anufactured from a Tier 1 supplier will incurs cost just 2 0 1 1 . A som ewhat lower R P E m ark up factor of 1 . 4 for their engineering into the vehicle system andrea lik ely used by NR C ( 2 0 0 2 ) and by S . A lbu, assistant M obile chief, to lead to som e warranty costs beyond those covered by the S ource D ivision, California A ir R esources Board, his in supplier. S till, the bottom - line m ark up over le variab m anupresentation to the com m ittee ( A lbu et al. , while 2 0 0the8 ) , facturing costs is very sim ilar: 2 . 0 5 for the niBorro Bird EP A has used a m ark up of approx im ately 1 . 03 8( )EP . A , 2 0 analysis versus 2 . 0 0 for the A NL analysis. A m ark up of approx im ately 2 over the direct -m anufac The V yas et al. ( 2 0 0 0 ) m em orandum alsohesum mturing arizcost ed tof parts m anufactured in house by an OE M was cost m ethodology used by EEA , Inc. , in a study thefor Ofice also supported by Bussm ann in a presentation, “S ytud of of Technology A ssessm ent ( OTA , 1 9 9 5 ) , hould although itindustrys average m ark up factors used to estim tail ate price re be noted that the auto industry has undergone dram tic a eq uivalents ( R P E) , ” to the com m ittee on J anuary 2 0 0 82 .4 , changes since that tim e, and the continued applicab ility of In that brieing, Bussm an cited a 2 0 0 3 study global of the the m ethodology is debatable. A gain, the cost categ ories difautom otive industry by M cK insey Global Institute, hich w fer, but the bottom - line m ark up over variable acturing m anuf cam e up with a m ark up factor of 2 . 0 8 , and nalysis his own a 17 1

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

17 2 TA BL E F . 1

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Com ponents of M anufacturer’s S uggested tail P riceR( eM S R P ) Eq uivalent R P E: A NL M ethod

Cost Category

Cost Contributor

R elative to Cost of V ehicle M anufacture

V ehicle m anufacture P roduction overhead

Cost of m anufacture W arranty R & D engineering D epreciation and am ortiz ation Corporate overhead, retirem ent,ealth h D istribution, m ark eting, dealers

1 .0 0 0 .1 0 0 .1 3 0 .1 1 0 .1 4 0 .4 7 1 .9 5 0 .0 5 2 .0 0

Corporate overhead S elling S um of costs P roit P roit Total contribution to M S R P

5 5 6 5 7 2 9 2 1

S hare ofP M( %S R ) 0 .0 .0 .5 .5 .0 3 .5 7 .5 .5 0 0 .0

S OU R CE: V yas et al. ( 2 0 0 0 ) .

TA BL E F . 2

Com ponents of M S R P : Estim Bird ated by Borroni-

Cost Category

Cost Contributor

V ehicle m anufacture

M aterials 0 .8 7 L abor, other m anufacturing costs 0 .1 3 Transportation and warranty 0 .0 9 A m ortiz ation and depreciation, engineerin gR & D , 0 .4 4 pension and health care, advertising, and overhead P rice discounts 0 .1 0 D ealer m ark up 0 .3 6 1 .9 9 0 .0 6 2 .0 5

F ix ed cost F ix ed cost S elling S um of costs P roit M S R P

R elative to Cost of V ehicle M anufacture

S hare ofP M( %S R )

4 6 4 2

2 .4 .3 .4 1 .5

4 1 9 2 1

.9 7 .6 7 .1 .9 0 0 .0

S OU R CE: A s reported by V yas et al. ( 2 0 0 0 ) .

TA BL E F . 3

Com ponents of R etail P rice Eq A uivalent: , Inc. EE , M ethod

Cost Category

Cost Contributor

R elative to Cost of V ehicle M anufacture

V ehicle m anufacture

D ivision costs D ivision overhead A ssem bly labor and overhead M anufacturing overhead A m ortiz ed engineering, tooling, and facilities D ealer m argin

0 .7 2 0 .1 4 0 .1 4 0 .2 2 0 .2 6 0 .4 9 1 .9 7 0 .1 7 2 .1 4

Overhead S elling S um of costs P roit Total

3 6 6 1 1 2 9 7 1

S hare ofP M( %S R ) 3 .6 .5 .5 0 .3 2 .1 2 .9 2 .1 .9 0 0 .0

S OU R CE: EEA , Inc. ( 1 9 9 5 ) , as reported . (by2 V0 0yas0 et) al .

TA BL E F . 4

Com parison of M ark up F actors

M ark up F actor for

A NL

In- house com ponents Outsourced com ponents

2 .0 0 1 .5 0

S OU R CE: V yas et al. ( 2 0 0 0 ) .

Borroni- Bird 2 .0 5 1 .5 6

EEA 2 .1 4 1 .5 6

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

17 3

AP P ENDIX F

of Chrysler data for 2003 - 2004, which produced fact ors of on the com plex ity of the part and the costs of inte grating it 1 . 9 6 - 1 . 9 7 . S ince these m ark up factors ct apply m anuto dire into the vehicle system . M ark eting, distribution, nd dealer a facturing costs, they are consistent with the estimates shown costs are m ultiplicative and add 2 5 percent toOEM the costs in Table F . 4 . L yons ( 2 0 0 8 ) used a m ark up roxfactor i- of(app F igure F . 1 ) . m ately 2 . 0 but was not speciic about the cost com nentspo included in the estim ate to which this factor waspplied. a R FLoEw= Su p p l ierCo 0 .0 8 ) + 0 .0 5 Lo w(st1 + 0 . 2 0 + Inform ation supplied to the com m ittee in the presen ta1 .3 5 ( 1 .2 8 ) + 0 .0 5 = 1 .7 8 (2 ) tion by D uleep on J anuary 2 5 , 2 0 0 8 , im mplies arkhigher up R FH Eig =h Su p p l ierCo (h 1 + 0 . 2 0 + 0 . 0 8 ) + 0 . 1 5 H ig st factors ( D uleep, 2 0 0 8 ) . A ssum ing a reference f 1 . 0 cost 0 o 1 .4 5 ( 1 .2 8 ) + 0 .1 5 = 2 .1 0 for the variable factors used to produce a com ponent ( m aterial, labor, energy, factory overhead) , EEA calcula tes the The resulting m ark up ranges are 2 . 2 2 to 2 . 5e 1 for th Tier 1 supplier cost by applying m ultiplicative mk ups ar for m ark up over variable costs ( corresponding to the LA N supplier overhead and proit and an additive factor of 0 . 1 to “vehicle m anufacturing” costs) and 1 . 6 5 to 1r the . 7 3 fo 0 . 2 for tooling, facilities, and engineering ( Table F . 5 ) . The m ark up over Tier 1 supplier costs ( correspondingtheto range is intended to relect the com plex ity of the omc ponent A NL cost of outsourced com ponents) . The full break own d and the engineering effort req uired of the supplierto ensure of EEA m ark up estim ates is shown in Table F . 5 . The m ark its integration into the full vehicle system . R epre senting the ups are com parable to those proposed by V yas et(al. 2 0 0 0 ) variable costs by X, the total supplier price m ark up is given but higher by a m eaningful am ount, as shown in F re F igu. 2 . by eq uation 1 : In a note, EEA - ICF , Inc. , argues that higher er suppli am ortiz ed costs are generally associated with lower OEMam Su p p l ierR P = X( E 1 + 0 . 2 0 + 0 . 0 5 ) + 0 . ortiz 1 0 ed = costs for any give™n part. H owever, this sertion as Lo w 1 . 0 0 ( 1 . 2 5 ) + 0 . 1 0 = 1 ( .13 )5 was not applied here to develop the range of m ark factors up Su p p l ierR P=h E X( 1 + 0 . 2 0 + 0 . 0 5 ) + 0 .based 2 0 on = EEA data. H ig 1 .0 0 ( 1 .2 5 ) + 0 .2 0 = 1 .4 5 A verage R P E factors can be inferred by costingall out the com ponents of a vehicle, sum m ing them to estim EM ate O In the EEA m ethod, OEM costs include am ortiz f ationTier o 1 costs or fully burdened in- house m anufacturi ng costs, tooling, facilities and engineering, and overhead,proit and and then dividing the sum into the selling price of the vehicle. selling costs, which include m ark eting, distributio n, and The com m ittee contracted with IBIS A ssociates) ( to 2 0 0 8 dealer costs. EEA assum es an average m anufacturer roit p conduct such an analysis for two popular vehicles: ( 1 ) the of 8 percent, som ewhat higher than the 5 percent sumas ed by H onda A ccord sedan and ( 2 ) the F ord F - 1 5uck 0 pick . up tr A NL and the 6 percent assum ed by Borroni- Bird.tizAedm orCurrent m odel year ( 2 0 0 9 ) designs and base m im odel tr costs vary from 5 percent to 1 5 percent, againnding depe levels ( no nonstandard options) were chosen. Base m odels

TA BL E F . 5

F uel Econom y Technology Cost M rs ark up F acto

Item

Cost L ow

S upplier costs F actors ( m aterials, labor, energy, factory overhea d) S upplier overhead S upplier proit A m ortiz ation of tooling + facilities + engineering S upplier subtotal S upplier m ark up

1 .0 0 0 .2 0 0 .0 5 0 .1 0 1 .3 5 1 .3 5

OEM

Cost H igh

S hare L ow %

1 .0 0 0 .2 0 0 .0 5 0 .2 0 1 .4 5 1 .4 5

S hare H igh %

4 5 9 2 4 6 1

4 0 8 2 8 5 8

1 2 5 2 8 0

1 2 5 6 8 0

costs

OEM overhead OEM proit Tooling + facilities + engineering am ortiz ation OEM subtotal OEM m ark up

0 .2 0 0 .0 8 0 .0 5 1 .7 8 1 .3 2

M ark eting, transport, dealer m ark up Total R P E m ark up ( over factors) R P E m ark up ( over supplier price)

0 2 2 1

.2 .2 .2 .6

5 2 2 5

0 .2 0 .0 0 .1 5 2 .0 1 .3

0 8

0 2 2 1

5 1 1 3

.2 .5 .5 .7

1 8

2 0 1 0 0

S OU R CE: EEA - ICF , Inc. , as reported by D presentation uleep in his to the com m ittee on J anuary 2 5 , 2 0 0 8 .

2 0 1 0 0

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

17 4

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

60%

Percent of RPE

50%

50.0% 48.0%49.0%

ANL

EEA

Chrysler

40% 30%

26.0% 24.0% 22.1%

23.5%22.9%22.5%

20% 8.0%

10% 2.5%

2.5%

0% Manufacturing Costs

F IGU R E F . 1

OEM OH, Amortization & Depr.

Profit

Selling Cost

Com ponents of retail price eq Puivalent E) m ( R ark OU up. SR CE: D uleep ( 2 0 0 8 ) . 3.00 Low

High

ANL

Multiplicative Markup

2.50

B-B

2.51 2.22 2.00

2.00 1.65

2.05

1.73 1.50

1.56

1.50 1.00 0.50 0.00 Over Tier 1 Price

F IGU R E F . 2

Over Factors

Com parison of D uleep ( 2 0 0gonne 8 ) high/ National low,LA aboratory r ( A NL ) , and Borroni-B-Bird B) (cost m ark up factors.

were chosen to reduce the inluence of m ark et pricin g deci1 . 4 9 to M S R P . The m ultiplier to dealerisinvoice 1 . 3 5cost , sions not driven by m anufacturing costs. which m eans that dealer costs, including proit, am unt oto Cost estim ates were developed for subcom ponents in about 4 percent of m anufacturing costs, not conside ring any term s of costs paid by OEM s for autom otive comts ponendealer incentives offered by OEM s. and subsystem s in ive broad system s. A lthough of m the any The base 2 0 0 9 F ord F - 1 5 0 s are two- door Xab L R egular com ponents are m anufactured in house, the coststhese of S tyleside short- bed, rear- wheel- drive pick ups produ ced in com ponents were estim ated using the ix ed or indirec t m anu- D earborn, M ichigan, and K ansas City, M issouri. curb The facturing costs norm ally borne by a Tier 1 supplier . R esults weight of the vehicle is 4 , 7 4 3 lb, with a standard V 8 , 4 .6 - L , for the base H onda A ccord are shown in Table F he . 6 base . T single overhead valve engine and a four- speed automatic vehicles are the four- door L X sedans produced inrysville, M a transm ission. The truck has a stam ped steel body fram on e Ohio, and L incoln, A labam a. The curb weight vehicle of this construction. D ealer invoice cost for the F - 1 5$ 02 0is, 0 5 5 , is 3 , 2 3 0 lb, with a V 6 , 3 . 0 - L , dual overhead gine, a camM enS R P is $ 2 1 , 5 6 5 , and the average m ark priceet transaction ive- speed m anual transm ission, and a stam ped unibody steel is $ 2 1 , 3 4 4 . The cost of all com ponents plus y is assem bl with a lightweight alum inum subfram e. D ealer e cost invoic $ 1 4 , 9 4 0 , as shown in Table F . 7 . This m eans ultiplier an R P E m for the A ccord is $ 1 8 , 8 3 0 , M S R P is average $ 2 0 , 7 5 of 5 1, and . 5 2thefor m ark et price and 1 . 5 4 for M kS up R facP . The m ar m ark et transaction price is $ 1 9 , 3 7 0 . The l com cost of po-al tor for the dealer invoice is 1 . 4 3 , so that dealer costs and proit nents plus assem bly costs is estim ated to be $ 14 4. ,This 5 6 am ount to about 9 percent of total m anufacturing sts,conot results in m ultipliers of 1 . 3 9 to m ark et transactio n price and including any possible OEM incentives to dealers.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

17 5

AP P ENDIX F

TA BL E F . 6

Cost Break down of Base 2 0 0 9 H Londa X A ccord A ccord L X Base 2 0 0 9 M ass ( k g)

P ower train Engine Battery F uel storage and delivery Transm ission Therm al m anagem ent D riveshaft/ ax le D ifferential Cradle Ex haust system Oil and grease P ower train electronics Em ission control electronics Body Body- in- white P anels F ront/ rear bum pers Glass P aint Ex terior trim H ardware S eals and NV H control Chassis Corner suspension Brak ing system W heels and tires S teering system Interior Instrum ent panel Trim and insulation D oor m odules S eating and restraints H V A C Electrical Interior electrical Chassis electrical Ex terior electrical Total com ponents F inal assem bly Interior to body Chassis to body P ower train to body Electronics to body Other system s to body Total m anufacturing NOTE: D OH C, double overhead cam system . S OU R CE: IBIS ( 2 0 0 9 ) .

BIBLIOGRAPHY

6 0 9 2 0 6 2 0 8 6 7 0 2 3 8 2 2 3 1

4 6 5 4 5 1 0 1 0 4 5 1 3 0 7 6 0 1 0 4 0 1 2 1 0 1 0 2 1 8 1 3 0 4 6 8 0 2 6 1 5 1 2 4 2 2 2 5 6 0 2 0 3 3 1 1 1 1 1 1 1 ,4 2 6 4 0 5 1 0 1 0 5 1 0 1 ,4 6 6

Cost ( $ ) 6 ,6 7 7 2 ,7 8 2 5 8 3 8 8 6 2 1 1 5 0 1 ,1 8 9 2 0 3 1 6 1 3 0 0 2 5 4 0 0 4 0 0 2 ,2 3 4 1 ,0 0 6 1 9 7 3 0 2 5 0 4 5 0 5 0 2 2 6 2 4 1 ,6 4 3 2 1 7 4 0 4 4 7 2 5 4 9 2 ,1 5 6 1 1 0 4 2 9 2 2 0 1 ,1 2 2 2 7 5 1 ,2 5 0 5 0 0 5 0 0 2 5 0 1 3 ,9 5 9 6 0 5 1 4 0 9 0 9 0 8 0 2 0 5 1 4 ,5 6 4

D etail I4 2 . 4 D OH C A L / A L L ead- acid, standard Gasoline, 1 8 . 5 gal M anual, 5 - speed

A lum inum

M idsiz e steel unibody S tam ped steel m idsiz e S heet steel Conventional, 4 m m S olvent- borne, average color

L ightweight A BS A ″lloy 1 6

shaft; H V A g, C, air conditioning, heatin cooling; NV H , noise, vibration and, harshness; and A BS , autom atic brak ing

D OT/ NH TS A ( U . S . D epartm ent of Transportation/ al H ighway Nation Trafic S afety A dm inistration) . 2 0 0 9 . A veragem F yuel S tandards, Econo A lbu, S . , California A ir R esources Board. 2 perspective 0 0 8 . A on R vehicle B P assenger Cars and L ight Truck s, M odel Y earinal 2 0R 0 ule. 1 :F 4 9 CF R technology costs for reducing greenhouse gas em issi ons. P resentation to P arts 5 2 3 , 5 3 1 , 5 3 3 , 5 3 4 , 5 3 6 NH , andTS 5 3A7 -, 2D0 ock 0 9 et- No. 0 0 6 2 , the National R esearch Council Com m ittee on Technolo gies for Im provR IN 2 1 2 7 - A K 2 9 . D OT/ NH TS A , W ashington, . D . C. M arc ing L ight- D uty V ehicle F uel Econom y on J anuary 2 4 . D uleep, K . G. 2 0 0 8 . A nalysis of technology retail cost price. and P resentaBussm ann, W . V . , and M . J . W hinihan. 2 tion 0 0 of9 Im . The pacts Estim on a tion to the National R esearch Council Com m ittee Technologies on for R etail P rices of R egulations: A Critiq ue of Aileutom Industry ob R etail Im proving L ight- D uty V ehicle F uel Econom 2y, 4J .anuary P rice Eq uivalent and Indirect Cost M ultipliers.pared P refor the A lliance of A utom obile M anufacturers, S outhield, M ich. . M ay 6

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

17 6 TA BL E F . 7

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Cost Break down of Base 2 0 0 9 F - 1 5 0 F - 1 5 0 P ick up X L Base M ass ( k g)

P ower train Engine Battery F uel storage and delivery Transm ission Therm al m anagem ent D riveshaft/ ax le D ifferential Cradle Ex haust system Oil and grease P ower train electronics Em ission control electronics Body Body- in- white P anels F ront/ rear bum pers Glass P aint Ex terior trim H ardware S eals and NV H control Chassis Corner suspension Brak ing system W heels and tires S teering system Interior Instrum ent panel Trim and insulation D oor m odules S eating and restraints H V A C Electrical Interior electrical Chassis electrical Ex terior electrical Total com ponents F inal assem bly Interior to body Chassis to body P ower train to body Electronics to body Other system s to body Total m anufacturing

9 2 2 3 0 8 2 9 1 0 2 1 1 8 4 5 1 5 0 3 7 2 5 6 8 1 5 1 0 1 6 6 7 2 5 0 0 5 5 2 0 5 1 1 2 1 2 1 3 1 0 3 4 8 1 1 9 7 9 1 0 5 4 4 1 2 8 2 4 2 8 2 2 4 0 1 5 2 7 7 1 0 1 0 2 ,0 9 8 5 2 1 0 1 0 1 0 1 0 1 0 2 ,1 5 0

Cost ( $ ) 7 ,6 6 6 3 ,9 7 1 8 4 4 4 0 1 ,0 6 8 1 5 0 6 0 8 1 1 6 1 0 3 3 0 0 2 5 4 0 0 4 0 2 ,2 5 8 1 ,0 2 0 1 7 7 6 0 2 5 0 4 5 0 5 0 2 2 6 2 4 1 ,7 1 9 4 1 3 5 2 0 3 3 4 4 5 3 1 ,5 7 0 1 0 0 3 5 0 1 5 6 8 2 0 1 4 4 8 3 2 2 3 2 4 0 0 2 0 0 1 4 ,0 4 5 9 0 5 2 0 0 1 5 0 1 5 0 1 0 0 3 0 5 1 4 ,9 5 0

D etail V 8 4 . 6 L S OH C CI/ A L L ead- acid, standard Gasoline, 2 5 gal A uto 4 pick up truck P ick up truck 2 W D steel L ight truck H ydroform ed steel

P ick up truck body on fram e S tam ped steel pick up truck M edium truck S olvent- borne, average color

P ick up truck 2 W D L ight truck A BS 4 - wheel S teel 1 7 ” P ick up truck

NOTE: S OH C, single overhead cam shaft. S OU R CE: IBIS ( 2 0 0 8 ) .

EP A ( U . S . Environm ental P rotection A gency) P A . 2008 S Technitaff. E Com m ittee on A ssessm ent of Technologies for Im ng Lprovi ight- D uty cal R eport: Cost and Effectiveness Estim ates of Tec hnologies U sed V ehicle F uel Econom y, J anuary 2 4 . to R educe L ight- D uty V ehicle Carbon D iox ide ns.Em EP issio A 4 2 0 -NR C ( National R esearch Council) . 2 0 0 2 . Effectivenes s and Im pact of CorR - 0 8 - 0 0 8 . A nn A rbor, M ich. porate A verage F uel Econom y ( CA F E) S tandards. nal A Natio cadem y IBIS A ssociates, Inc. , W altham , M ass. 2 llection 0 0 8 and . D Aatanalysis: Co P ress, W ashington, D . C. V ehicle S ystem s Costs. R eport to the Nationalrch R Council esea Com OTA ( Ofice of Technology A ssessm ent) . 1 9 9 5d A . Autom dvance otive m ittee on A ssessm ent of Technologies for Im proving L ight- D uty V ehicle Technology: V isions of a S uper- Eficient F am ily OTA Car. - ETI- 6 3 8 . F uel Econom y. D ecem ber. W ashington, D . C. L yons, J . M . , S ierra R esearch, Inc. 2 0 0 and 8 . retail Technology price im pliV yas, A . , D . S antini, and R . Cuenca. 2 0on0 of 0 Indirect . Com Cost paris cations of H R 6 CA F E standards based on vehicle lation simm u odeling M ultipliers for V ehicle M anufacturing. Centerransportation for T R e( prelim inary results) . P resentation to the National R esearch Council search, A rgonne National L aboratory. A rgonne, A pril. Ill.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

G Compression-Ignition Engine Replacement for Full-Size Pickup/SUV

The analysis and discussion for the m ain part of Ch apter 5 in full- siz e pick ups would be replaced by a V 6ngine CI eas were based on two vehicle classes—nam ely, a m idsiz sedan e long as the torq ue and power req uired for eq ualform per ance such as the A ccord, Cam ry, F usion, or M alibu m and idsiza e could be achieved. W ith a base- level speciication t a speciic a S U V such as the D urango, Ex plorer, or Trailblaz To enable er. torq ue of 1 6 0 N- m / L , the displacem ent areq CI uired V 6 for projections for the entire range of vehicle classes discussed to replace an S I V 8 of the displacem ent range 6 5. 2. 3L - would in Chapter 9 , it was necessary to create an additio nal engine be 4 . 4 - 5 . 2 L , which is really too large forconigurathe V 6 speciication to provide a CI replacem ent for the 35 -. to 6 . 2 - Ltion. H owever, from a cost point of view, the V niguration 6 co V 8 S I engines which would be found in full- siz ye bod onwould be preferable to a V 8 if a V 6 concept could e identib fram e pick up truck s such as the F 1 5 0 , the S ilverado,iedand that m eets the req uirem ents. If no base- oniguralevel c the R am 1 5 0 0 and S U V s such as the Ex pedition hoe. and tion Ta were considered, an advanced- level V 6 of 3 could .5 L Table 5 . 5 in Chapter 5 described a V 6 CI engine h diswit easily provide suficient torq ue to replace a 6 . 2S- ILV 8 and placem ent between 2 . 8 and 3 . 5 L appropriatesizfore m id could be m anufactured with the sam e set of tooling as the S U V s and m idsiz e pick up truck s. F or cost here reasons,V t 6 engine whose cost increm ents are described bles in Ta5 . 5 is a range of displacem ents for which OEM s would ndteto and 5 . 8 . Therefore, for the full- siz e pick up ofclass vehicles, design and build V 6 rather than V 8 engines since s req V uire 6 it was assum ed in this analysis that the CI replace m ent for S I fewer parts. F or CI engines, this V 6 range would from be V 8 engines would be a V 6 of displacem ent upL to with 3 .5 about 2 . 9 L to perhaps 4 . 5 L . It was therefore m edassu in advanced- level technology. Cost estim ates for such an engine this additional analysis that the V 8 S I enginesically typ used are shown in Tables G. 1 to G. 3 .

17 7

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

17 8

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

TA BL E G. 1 Increm ental CI- D iesel Engine Cost ions Estim to R ateplace S I M P F I OH V Two- V alveV5 .83 Engine - to 6 . 2 - L in a F ull- S iz e Body- on- F ram e P ick up ( e. o and g. , RS ilverad am ) or S U V with a 3 . 5 - L V 6 D OH C CI 5 0 - S tate S aleable U L EV II 3 . 5 - L V 6 ngine, D OH Baseline: C CI- D iesel E S I Gasoline OH V 4 - V 5 . 3 - to 6 . 2 - L V 8

Estim ated Cost V ersus Baseline ( $ )

Com m on- rail 1 , 8 0 0 bar piez o- actuated fuel th system six injectors wi ( @ $ 7 5 ) , high- pressure pumfuel p (rail, $ 2regulator 7 0 ) , and 9 1 1 fuel storage upgrades plus high- energy driver upgrades to the engine control m odule. Credit for M Pontent F I cdeleted ($ 4) 8. S eries seq uential turbocharging: One V GT with elect ronic controls and one ix ed- geom etry turbocharger ithwactive and passive 8 3 0 bypass valves necessary to m atch high EGR rateslow at load conditions ( $ 7 5 0 ) . W ater- air charge oler, air circulation co pum p, therm ostat/ valve, and plum bing. Engine downsizredit ing from c V( $8 2 0.a 0 ) U pgrades to electrical system : starter m otor,nator, alter battery, and 1 . 5 - k W supplem entalcabin electrical heater as is standard in 1 6 7 Europe ( $ 9 9 ) . Cam , crank , connecting rod, bearing, and piston rades, upg oil lines ( $ 6 2 ) plus NV H counterm engine easures( to $ 4 7 ) and vehicle 1 9 4 ($ 8 5 ). 2 2 6 H igh- and low- pressure EGR system to suppress light and heavy loads. Includes hot- side and co ld- side electronic rotary x at NO diesel EGR valves plus EGR cooler and all plum bing. A dd rem aining com ponents req uired for advancedl technology leve ( details in Table G. 3 ) . 3 0 8 Em issions control system including the followingnctionality: fu D OC, CD P F , selective catalyticon reducti ( S CR ) , urea dosing 1 , 0 4 0 system ( $ 3 6 3 ) . S toichiom etric M P F I aporative em issions system and evs credit$( 3 4) . 3 On- board diagnostics ( OBD ) and sensing, including our tem f perature sensors ( @ $ 1 3 ) , wide- range ratio air/ sensor fuel ( $ 3 0 ) x, NO 2 2 7 sensor ( $ 8 5 ) , two- pressure sensing glow plugs () @ , six$ glow 1 7 plugs ( @ $ 3 ) , and D elta- P sensor ( $ 2for5 D) . PCredit F for four switching O2 sensors (@ $) .9 Total variable cost with credits for S I parts rem ed ovex cludes any necessary transm ission, chassis,driveline or upgrades. 3 ,9 0 3 NOTE: A ftertreatm ent system cost estim ates relect2 A0 0pril 9 P GM prices. Estim ates derived from M artec, (catalyz 2 0 0 ed 8 )diesel . CDparticulate P F ilter; CI, com pression ignition; D OC, diesel ox idation alyst; catD OH C, dual over head cam ; D P F , ulate dieselilter; particD P F , diesel particulate ilter; EGR haust, ex gas recirculation; M P F I, m ultipoint fuel injection; NV H , noise, vibration, harshness; OBD , on-agnostics; board di OH V , over head valve; P GM , platinum p grou m etals; S CR , selective catalytic reduction; rk S I,ignition; spa U L EV II, ultra- low- em issions V vehicle; GT, variable geom etry turbocharger. a Credit for downsiz ing from V 8 to V 6 referredCto4 D- V OHV 8 downsiz ed to D OH C 4 V V 6 dit . In used thisby case, M cre artec was reduced from $ 2 7 0 to $ 2 0 0 since the parts rem oved from an OH would V 2 -cost V less V than 8 those rem oved from a D OH VC 48 -. V

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

17 9

AP P ENDIX G

TA BL E G. 2 Com pliance

Cost Estim ates of Ex haust Em issions treatm A ent fterTechnologies Capable of Enabling Tier 2Bin , 5

Item D OC 1 M onolith and can P GM loading D OC 2 M onolith and can P GM loading EGR catalyst M onolith and can P GM loading Coated D P F A dvanced cordierite brick and can P GM loading NS C system Catalyst brick and can P GM loading S CR - urea system S CR brick and can U rea dosing system S toichiom etric gasoline em issions and evaporative system credit Em issions system total

M idsiz e Car M idsiz e S U V F ull- S iz e P ick up ( e. g. , M alibu) , ( e. g. , Ex plorer) , ( e. g. , Ex plorer) , Catalytic D evice S iz ing Catalytic D evice S iz ing Catalytic D evice S iz ing Based on 2 . 0 - L Based on 3 . 5 - L Based on 4 . 4 - L ( A pril 2 0 0 9 P GM prices) ( A pril 2 0 0 9 P GM prices) ( A pril 2 0 0 9 P GM prices) ($ ) ($ ) ($ ) 5 2 1 3 9 Not used Not used 7 1 3 1 2 4 1 3 1 1 1 4 3 1 4 3 9 P assive S CR −2 4 5 6 8 8

5 2 2 0 0 5 2 7 0

5 2 2 5 2 5 2 8 7

Not used Not used 2 7 0 2 6 Not used Not used 2 7 4 3 6 3 −3 4 3 9 6 4

Not used Not used 2 7 0 3 3 Not used Not used 2 7 4 3 6 3 −3 4 3 1 ,0 4 0

NOTE: This table com plem ents Table 5 . 5 . Com Table pared5to. 5 , the colum ns relecting Novem ber 2 0 prices 0 7 (P Colum GM ns 2 and 4 ) have been rem oved and a new colum n, Colum n 4 , was added. This colum relectsnthe aftertreatm ent system cost estim ate thefor ex haust low rates of a larger base- level V 6 CI engine ( i. e. , 4 . 4 L ) suitable for replacing65. .25- -L totwo- valve OH V V 8 S I engines with ced3 .level 5 -L technology advan CI engines. Note that, as disc ussed in Chapter 5 , it was assum ed that the aftertreatm t com en ponent siz es for the 3 . 5 - L advanced- level re eqVual6 toa those of a base- level 4 . 4 - L V 6thebecause power levels for these two engines would be the same, thus req uiring the sam e ex haust low rates. ost A estim ll c ates are based on A pril 2 0 0 9 P GM com m odity prices. Colum n 4 provides the estim ate used for aftertreatm the ent costs in Table G. 1 .

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

18 0

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

TA BL E G. 3 Estim ates of Increm ental Costs to nt ImD plem evelopm e ents W hose Estim ated F uel Consumduction ption R e Gains A re S um m ariz ed in Table 5 . 2

Item

M idsiz e Car ( e. g. , M alibu) 1 .6 - L L 4

D ownsiz e engines 2 - L L 4 to 1 5. 60 L , 3 . 5 - L V 6 to 2 . 8 L , 4 . 4 - L V 6 to 3 .5 L Two- stage turbocharger system 3 7 5

D ual- pressure oil pum p

5

Nonrecirculating L P fuel pum p

1 0

L ow- pressure EGR

—

D irect- acting H P ( m ax im um8 0 injection pressures > 2 , 0 0 0 bar) piez o injectors Total 5 2 0

M idsiz e S U V F ull- siz e P ick up ( e. g. , Ex plorer) ( e. g. , R am 1 5 0 0 ) 2 .8 - L V 6 3 .5 - L V 6 7 5

7 5

5 4 5

6

0a

6 1 2

9 5

1 2 0

8 5 3

1 2 9 5

1 2 0

H igher load capacity rod bearings and head gask et for higher cylinder pressures ( ~ $ 1 2 . 5 0 / cylinder) A dditional air low control valves, piping, cost of additional turbo, water- to- air intercooler with control valve, separate pum p S witchable pressure valve relief for high or low oil pressure V ariable L P pum outputp controlled by H P pum p output A dditional piping ( ~alves $ 2( 0e. )g. and , v integrated back pressure and L P EGR rate ~ $ 7 5 ) , m uch m ore dificult to pack age for V 6 engine with underloor D P F , cost for L - 4 already included in Table 5 . 4 $ 2 0 / injector, beneits derived ion from com binat of higher rail pressure and m ore injector controllability

3 0 8

NOTE: These developm ents are CI- diesel downsiz ing romf base level to advanced level, therm odynam rovem ic im pents, friction reduction, and engine accessory im provem ents. Total for full- siz e body- one pick framup ( $ 3 0 8 at bottom of Colum n 4 ) used G. 1in. Table F C, fuel consum ption. aTwo- stage turbo system already com prehended in eTabl G. 1 .

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

H Other NRC Assessments of Beneits, Costs, and Readiness of Fuel Economy Technologies

e th The National R esearch Council ( NR C) has conducted was to ex am ine the research program , com m unicate program ’s progress to governm ent and industry parti cipants, other studies to estim ate beneits, costs, and readi ness of fuel and identify barriers to the program ’s success. The P NGV econom y technologies for light- duty vehicles. Indee d, this program was a cooperative research and developm ent procom m ittee’s task is to update the estim ates provide d in one of tates C the earlier studies, Effectiveness and Imp act o f Co rp o rate Aver-gram between the governm ent and the U nited S ouncil for A utom otive R esearch, whose m em bers include three the ag e F u el Eco no my ( CAF E) which Standards, was issued in original eq uipm ent m anufacturers ( OEM s) in ed the U nit 2 0 0 1 . The com m ittee discusses several other here. studies The pany,Com R eview o f the R esearch P ro g ram o f the Po artnership r a New f S tates: D aim lerChrysler Corporation, F ord M otor and General M otors Corporation. The P NGV was envisioned Generatio n o f V ehicl es: Seventh R ( ep NRo C, rt 2 0 0 1 ) assessed to allow the parties to cooperate on precom petitive research the fuel econom y technologies and costs associated with three activities that would ultim ately result in the depl oym ent of prototype vehicles built in connection with the P ar tnership for technologies to reduce our country’s fuel consum pti on and a New Generation of V ehicles ( P NGV ) research m progra to to im pr achieve up to three tim es the fuel econom y of a 41 9fam 9 ily em issions of carbon diox ide. The P NGV aim edove the com petitiveness of the U . S . m anufacturing for future base sedan. M ore recent NR C studies that have look different ed at generations of vehicles and to introduce innovative technoloaspects of fuel econom y technologies includeTransitio ns to fuel conAl ternative Transp o rtatio n Techno l o g ies—A FH oycu dros o- ngies into conventional vehicles in order to im prove g en( NR C, 2 0 0R 8eview a) , o f the R esearch P ro g ram o sum f the ption or reduce em issions. The inal goal ofPtheNGV was to develop prototype vehicles that achi eve up F reedo mCAR and F u el P artnership : Seco( nd NRR C,ep oprogram rt 2 0 0 8 b) , and the report from the A m erica’sture Energy Fto uthree tim es the average fuel econom y of a 1 9am9 4ily f It was recogniz ed that these new vehicles wou ld ( A EF ) P anel on Energy Eficiency, R eal P ro sp ects fo r Energsedan. y to be sold in high volum e in order to have anim pact. Eficiency in the U nited States ( NA S - NA E- NR C, 2 0 1 0have ) . Even icle was though the recent report Transitio ns to Al ternative Transp o rta- F or this reason, the strategy for the prototype veh to develop an affordable fam ily sedan with a fuelconom e y tio n Techno l o g ies—P l u g - In H y b rid El(ectric NR C, V ehicl es of up to 8 0 m pg that m aintained the perform zance, e, and si 2 0 0 9 ) was not strictly a report on fuel economhnology, y tec it safety standards of the vehicles of that tim e. A fter 2 0he0 2 , t did address the costs and beneits of plug- in electric vehicles. program transitioned to the F reedom CA R and earch F uel R es W hile the task s req uired under each study are rent, diffe ( F reedom CA R ) P rogram , discussed in the ction. following se som e of their analyses of costs, eficiencies, androspects p Each of the three autom obile com panies involvedthe in for the various technologies overlap and are reviewed here. P NGV program built its own prototype concept vehicl es H owever, the com m ittee does not attem pt to he review ind-t since this could not be done in the contex t of precom petitive ings of any studies other than those of the NR C. It sim ply l three al com m ents on them , as appropriate, to the degree t thetha research. By the tim e of the seventh NR C report, com panies had built prototypes that m et the thentant ex NR C reports are based on them . perform ance, com fort, cargo space, utility, and ety saf req uirem ents. These prototype vehicles could not, ever, how REVIEW OF THE RESEARCH PROGRAM OF THE m eet the price target while sim ultaneously im provin g fuel PARTNERSHIP FOR A NEW GENERATION OF econom y to near 8 0 m pg. The D aim lerChrysler pe prototy VEHICLES, SEVENTH REPORT foresaw a price prem ium of $ 7 , 5 0 0 , whiletwo the other The task of the NR C S tanding Com m ittee to R e eviewdid th not announce any price prem ium associated with their R esearch P rogram of the P NGV ( NR C P NGV comvehicles. m ittee)A ll three concept vehicles used hybrid ectric el 18 1

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

18 2

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

power trains with sm all, turbocharged, com pressionignition plug- in hybrid electric vehicles ( P H EV s) . TheasNR thusC h direct- injection engines using diesel fuel. A ll ee thrwere far reviewed the F reedom CA R and F uel P artnership ice, tw start- stop hybrids that shut the engine off when idling. The with reports published in 2 0 0 5 and 2 0 0 8 . ond In the of sec report from the NR C P NGV com m ittee estimualated thatthese d reports, one of the NR C F reedom CA R com s m ittee’ m ode batteries would probably cost $ 1 , 0 0 0 toper $ 1 , 5 task 0 0 s was to com m ent on the balance and adeq uacy the of battery unit ( 1 . 5 k W h) , or $ 6 7 0 to $ 1 NR , 0 0C,0 per efforts k Wandh on ( the progress achieved since the 2 0 0report. 5 2 0 0 1 ) . Each com pany took a different routeetothereduc The conclusions and recom m endations of the second eport r vehicle m ass and aerodynam ic drag and to supply pow er focus on the P artnership’s m anagem ent and oversight but for aux iliary loads. The high cost of the lightweig ht m atealso provide the F reedom CA R com m ittee’s opinion the on rials and electronic control system s m ade the price target readiness of new fuel econom y technologies. unattainable. In addition, the cost of the com pres sionThe NR C F reedom CA R com m ittee report recogniz es ignition direct- injection engine was greatly increased by the that m ore eficient IC engines will contribute the m ost to ex haust- gas after- treatm ent system s to controlsions. em is reducing fuel consum ption and em issions in the near term . In the m iddle of the P NGV program , the Tier 2ionem iss The P artnership focuses research on lean- burn, dire ctstandard was prom ulgated, and the NR C P NGV com e m injection itte engines for both diesel- and gasoline- fue led vebelieved that the ability of the diesel engine to meet em ishicles, speciically on low- tem perature com bustion ngines e sions targets was not clear. and aftertreatm ent of the ex haust. The report recog niz es The NR C P NGV com m ittee reported that the P NGV that, after com pleting the research necessary to ove pr a program had m ade signiicant progress in im plemg entintechnology’s viability, there are typically several years desirable technologies as fast as possible. Each of the three of prototyping and developing m anufacturing process es autom obile m anufacturers in the P NGV dem onstratedbefore a the technology can be introduced into the vehicle hybrid electric vehicle before the end of the P artn ership in leet. Because of the urgent need to reduce vehicle fuel 2 0 0 4 . They had developed the concept vehicles 0by02 ,0but consum ption, the developm ent phase of these technol ogies the goal of the developm ent of a preproduction prot otype by has been accelerated while researchers are still studying 2 0 0 4 was not m et because of the term ination P of NGV the the controlling therm ochem istry of low- tem perature com program . Indeed, the m anufacturing and engineering innovabustion. The result is close coordination between those tions that cam e out of the P NGV program were im ented plem look ing to ex pand the fundam ental k nowledge base d an before 2 0 0 0 . In the end, the three OEM s demd that onstrate those investigating applications. The report from het NR C a production m edium - siz e passenger car could be duced pro F reedom CA R com m ittee recom m ends that pthe P artnersh that achieved 8 0 m pg, and one OEM ( D aim lerChrysler) investigate the im pact on em issions of com bustion ode m dem onstrated that such a vehicle could be produced at a cost switching and transient operation with low- tem perat ure penalty of less than $ 8 , 0 0 0 . com bustion, and it q uestions how m uch ex hausty energ can actually be recovered. F urtherm ore, the NR C F CA reedom R com m ittee suggests the P artnership closely analyz the e THE FREEDOMCAR AND FUEL RESEARCH PROGRAM cost- effectiveness of the ex haust gas heat recovery research REPORT and the potential fuel eficiency beneits before deciding The task of the NR C Com m ittee on R eview of the whether to pursue this research further. F reedom CA R and F uel R esearch P rogram ( NR C F reedom A nother- goal of the F reedom CA R and F uel P artnership CA R com m ittee) is to assess the F reedom CA R and is toFdevelop, uel by 2 0 1 5 , battery storage for hybrid elecP artnership’s m anagem ent and the research and devel optric vehicles that has a 1 5 - year life and a pulseower p of m ent activities overseen by the P artnership. ThertnerP a 2 5 k ilowatts ( k W ) , with 1 k W of pulse power $ 2 0 costing . ship, started in 2 0 0 2 , built on the earlier P NGV ogram pr. This effort focuses on lithium ( L i) ion batteries, which are F reedom CA R , lik e P NGV , is a collaboration he between simt ultaneously in both the research phase, as thenowledge k governm ent and industry to support a wide range ofprebase for speciic electrochem ical system s is ex pande d, com petitive research in autom otive transportation. The and the developm ent phase, as the batteries are bui lt and P artnership’s goal is to study technologies that wi ll help tested. S igniicant progress had been m ade since the irst the U nited S tates transition to an autom otive free leet from F reedom CA R report ( NR C, 2 0 0 5 , 2 0 0 8p b) . The P a petroleum use and harm ful em issions ( NR C, 2 e0 0 5has ) . dem Th onstrated batteries that ex ceed the req uirem ent for vision of the P artnership is to enable a transitionpathway a 3 0 0 , 0 0 0 - cycle lifetim e, that have longerlives, calendar that starts with im proving the eficiency of today’sinternal and that operate over a wider tem perature range tha n earlier com bustion ( IC) engines, increasing the use of hybr id elecbatteries. The NR C F reedom CA R com m ittee recogniz ed tric vehicles, and supporting research in fuel- cell - powered that cost is the prim ary barrier for introduction fo the vehicles so that a decision can be reached in 2 0 1on5 the L i- ion battery to the m ark et and com m ends the er- P artn econom ic and technological viability of hydrogen- wered po ship for researching lower cost m aterials for the athode c vehicles. In 2 0 0 9 , a greater em phasis beganlaced to beon p and the m icroporous separator. The report from NR the C

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

AP P ENDIX H

18 3

F reedom CA R com m ittee recom m ended that hipthe P artners in a position to begin signiicant com m ercializ ation until at do a thorough cost analysis of the L i- ion batteries under least 2 0 2 0 , 5 years later than the target date m assu ed in the developm ent to account for recent process and m ials ater hydrogen study. costs and for increased production rate costs. The task also called for the NR C hydrogen com m toittee A 5 0 percent reduction in total vehicle weight ato naddiconsider whether other technologies could achieve signiitional cost is another k ey goal of the P artnership; it would cant CO2 and oil reductions by 2 0 2 0 . The NR C hydrogen rely on the widespread application of advanced high- strength com m ittee considered im provem ents to spark -( ignition S I) steels, alum inum alloys, cast m agnesium , and - ibercarbon engines, com pression- ignition ( CI) engines, vehicle transreinforced plastics. The NR C F reedom CA R com m mittee issions, and hybrid vehicle technologies as wells areducconcluded that the goal of price parity for the lightweight tions in weight and other vehicle load reductions. Im provem aterials is insurm ountable within the tim e fram f thee o m ents also could com e in the form of reductions weight in P artnership ( NR C, 2 0 0 8 b) . H owever, the eight 5 0 percent andwsim ilar im provem ents. The technical im provem s that ent reduction goal is critical for the P artnership’s ov erall vision can be applied to S I engines include variable valvetim ing of a hydrogen- fueled car. The NR C F reedom CA R - com and m lift, it cam less valve actuation, cylinder deactiv ation, the tee went beyond that, saying the weight reduction would be use of gasoline direct injection with turbocharging, and inm andatory even with the associated cost penalty, cause be the telligent start- stop, which involves engine shutoffwhen the alternative adjustm ents to the engine and batteries would cost vehicle idles. Im provem ents in vehicle transm sission include m ore. The NR C report recom m ends m aintaining per-the 5 0the use of conventional 6 / 7 / 8 - speed autom atic m trans issions cent weight reduction goal and analyz ing cost- effec tiveness and autom ated m anual transm issions. This report eatsrep an to conirm that the added cost of weight reduction an c be estim ate from D uleep ( 2 0 0 7 ) that com bining ectionsthe proj offset by m odifying the fuel cell and battery goals . for im provem ents in the engine, transm ission, t,weigh parasitic loss ( including friction losses, rolling resi stance, and air drag) , accessories, and idle- stop com ponents could reduce THE HYDROGEN REPORT fuel consum ption in 2 0 1 5 by 2 1 to 2 9 percent ve to relati The task s of the Com m ittee on A ssessm ent of eR esourc today’s vehicles and in 2 0 2 5 by 3 1 to 3 7 able percent. H . T1 Needs for F uel Cell and H ydrogen Technologies ( NR the C shows the im provem ents estim ated for S I engines ribut-att hydrogen com m ittee) was to establish the m ax im acti-um pr able to these approaches. The NR C hydrogen reportlso a cable num ber of vehicles that could be fueled by hy drogen q uotes studies by H eywood and colleagues at M assach usetts by 2 0 2 0 and to discuss the public and private fundi ng needed Institute of Technology ( M IT) on the fuel eficiency of lightto reach that num ber. The NR C hydrogen com m -ittee as duty vehicles ( W eiss et al. , 2 0 0 0 ; H eywood, asseris 2 0 0 7 ; K sum ed that ( 1 ) the technical goals for fuel cell hicles, ve and H eywood, 2 0 0 7 ; K rom er and H eywood,uel2 0 0 7 ) . T which were less aggressive than those of the F reedo m CA R econom y im provem ents noted in the M IT workrom result f P artnership, are m et; ( 2 ) that consum ers would ily accept read changes to the engines and transm issions and approp riate such vehicles; ( 3 ) that governm ent policies would rive dthe reductions in vehicle weight. The M IT work assum thates the introduction of fuel cell vehicles and hydrogen production im provem ents are aim ed entirely at reducing fuel nsum co pand infrastructure at least to the point where fuel cell vehicles tion. Table H . 2 shows the im provem ents in fuel om econ y are com petitive on the basis of lifecycle cost; and ( 4 ) that oil com pared to a 2 0 0 5 S I engine vehicle that M ates IT estim prices are at least $ 1 0 0 per barrel by 2 0 2 0 0( 0NR 8 a) C,. 2could be achieved by 2 0 3 0 , although the NR C hydroge n Thus, the scenarios developed in the hydrogen report are not com m ittee assum ed that these levels of fuel econom wouldy projections but a m ax im um possible future m all arkas-et if not be available as q uick ly. sum ptions are m et. The NR C hydrogen com m ittee udedconcl that although durable fuel cell system s at signiica ntly lower costs are lik ely to be increasingly available for ightl duty vehicles over the nex t 5 to 1 0 years, the F reedom R P CA art- TA BL E H . 1 P otential R eductions in F uel Consum ption nership goals for 2 0 1 5 are not lik ely to be me NR et. Th C ( gallons per m ile) for S park - Ignition V ehicles ctedEx pe hydrogen com m ittee also concluded that com m ation ercializ from A dvances in Conventional V ehicle Technology by and growth of these hydrogen fuel cell vehicles could get Category, P rojected to 2 0 2 5 under way by 2 0 1 5 if supported by strong governm polient 2 0 0 6 - 2 02 10 51 6 - 2 0 2 5 cies. Those conclusions are m ore optim istic than e concluth (% ) (% ) sions on fuel cells contained in this report, whosecom m ittee Engine and transm ission 1 2 -1 6 1 8 -2 2 ( though it did not consider the potential im pact of policies W eight, drag, and tire loss reduction 6 -9 1 0 -1 3 on fuel cell m ark et potential) does not ex pect ress progon A ccessories 2 -3 3 -4 fuel cell costs and technology to be as rapid as expected by Intelligent start- stop 3 -4 3 -4 the NR C hydrogen com m ittee. F urther, one OEM s ag- that i NOTE: V alues for 2 0 1 6 - 2 0 2 5 include those1 of5 2. 0 0 6 - 2 0 gressively pursuing fuel cell vehicles will probably not be S OU R CE: D uleep ( 2 0 0 7 ) .

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

18 4

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

TA BL E H . 2 Technology

Com parison of P rojected Im provem ehicleents F uel in V Consum ption from A dvances in Convention al V ehicle

F uel Consum ption (L /1 0 0 k m ) 2 2 2 2 2 2 2 2 2

0 0 0 0 0 0 0 0 0 aF bF

0 0 0 0 3 3 3 3 3

5 5 5 5 0 0 0 0 0 rom rom

Gasoline D iesel Turbo H ybrid Gasoline D iesel Turbo H ybrid P lug- in

8 .8 7 .4 7 .9 5 .7 5 .5 4 .7 4 .9 3 .1 1 .9

R elative to 2 0 0 5 R elative to 2 0 3 0 R elative to 2 0 0 5 Gasolinea Gasolinea Gasolineb 1 .0 0 0 .8 4 0 .9 0 .6 5 0 .6 3 0 .5 3 0 .5 6 0 .3 5 0 .2 1

1 .0 0 0 .8 5 0 .8 9 0 .5 6 0 .3 4

R elative to 2 0 3 0 Gasolineb

0 .6 1 0 .4 5 0 .5 4 0 .3 8

1 .0 0 0 .7 7 0 .8 8 0 .6 1 5

K rom er and H eywood ( 2 0 0 7 ) . W eiss et al. ( 2 0 0 0 ) .

A lthough theNR C hydrogen com m ittee ack nowledgesto include plug- in hybrid electric vehicles. The co m m ittee the potential for hybrids outlined in K rom er andywood, H e reconvened to ex am ine the issues associated with P EVH s it concluded that advances in hybrid technology are m ore and wrote Transitio ns to Al ternative Transp o rtatio n Techlik ely to lower the cost of battery pack s than toncrease i fuel no l o g ies—P l u g - in H y b rid El ectric ( referred V ehicl to here es econom y signiicantly. This would increase their app eal to as the P H EV report) to that additional task ( 0NR0 9C,) 2. consum ers relative to conventional vehicles and, us, th their In accordance with the com m ittee’s statem ent kof,tas the m ark et share ( K rom er and H eywood, 2 0 0 y7 the ) . To sim P Hplif EV report does the following: analysis in the hydrogen report, the NR C hydrogenom c m ittee assum ed that hybrids reduce fuel consum ption constant a • R eviews the current and projected status of P H EV 2 9 percent annually relative to conventional vehicl es, which technologies. also im prove each year. This value is within thenge ra of the • Considers the factors that will affect how rapidly potential for power split hybrids in the present report. P H EV s would enter the m ark etplace, including the Thus, the NR C hydrogen com m ittee judged that hybrid interface with the electric transm ission and distri bution electric vehicles could, if focused on vehicle eficiency, system . consistently reduce fuel consum ption 2 9 percentative rel • D eterm ines a m ax im um practical penetration for rate to com parable evolutionary internal com bustion engi ne P H EV s consistent with the tim e fram e of the 2 0 0 8 vehicles ( ICEV s) . A lthough this judgm ent is ative conserv H ydrogen R eport and other factors considered in ttha com pared to that of K rom er and H eywood, itads still to le report. a 6 0 - m pg average for new spark - ignition hybrids 2 0 by 5 0 . • Incorporates P H EV s into the m odels used in the 2 0 0 8 This m eans that hybrid technologies will have reach ed their H ydrogen R eport to estim ate the costs and im pacts greatest fuel consum ption reductions by 2 0 0 9 atand future th on petroleum consum ption and carbon diox ide2() CO im provem ents in hybrid vehicle fuel econom y would e pri-b em issions. m arily attributable to the sam e technologies that educe r fuel consum ption in conventional vehicles. Thus, hybrid vehicles A s in this report, the P H EV report considered ypes two t reduce fuel consum ption by 2 . 6 percent per year m fro2 0 1 0 of P H EV s, a P H EV 1 0 with an all- electric mrange iles of 1 0 through 2 0 2 5 , 1 . 7 percent per year in 2 0 2d 50 -. 25 0 3and 5 ,a PanH EV 4 0 with an all- electric range of 4. Both 0 m iles percent per year between 2 0 3 5 and 2 0 5 0 , thedosam ereports as use the sam e architectures as this com me, itte which evolutionary ICEV s. include a spark - ignited internal com bustion engine, two electrical m achines, power electronics, and a L ni-batio tery. Only the irst task relates to our report, and com paring PLUG-IN HYBRID ELECTRIC REPORT the two, it is necessary to separate the current technology A fter the publication of the NR C report Transitio ns status and the projections. The assessm ent of curre nt techto Al ternative Transp o rtatio n Techno l o g ies—A F o cu s o nin the P H EV report is in close agreem ith nologies entthe w H y dro g( NR en C, 2 0 0 8 ) , the U . S . D epartm entassessm of Energy ent of this com m ittee. Both discuss the erent diff ask ed the Com m ittee on A ssessm ent of R esource for Needsbattery chem istries and the advantages and problem ofs F uel Cell and H ydrogen Technologies to ex pand nalysis its a each and point out how P H EV s differ from batteries for

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18 5

AP P ENDIX H

H EV s, because the critical param eter is the energy available 2 0 1 0 ) , the panel estim ated the current contribution s and fuas opposed to the power needs. The discussion of power ture potential of ex isting technologies. In additio n, the energy electronics and m otors and generators within the PEV H eficiency panel estim ated the potential for new tec hnologies report again generally parallels what is in this report. There that could begin to be com m ercially deployed in the nex t are som e differences in term s of the technological needs. decade, the associated im pacts of these technologie s, and F or ex am ple, the P H EV report assum es that oling liq uid co the projected costs per unit of reduction in energy dem and. is assum ed to be req uired for the P H EV 4 0 ck battery s paThe panel’s work on light- duty vehicles is sum medariz in whereas this report assum es air cooling will be suf icient. the following sections. The P H EV report was req uired to project and analyz e the technology costs to 2 0 5 0 , while this report pped sto at Gasoline SI Engine 2 0 2 5 . The m ethodology used is sim ilar, andcases in both the costs were built up by adding the costs of the new com Gasoline S I engine eficiency im provem ents contem ponents needed com pared to an internal com bustion ngine e plated by the NR C energy eficiency panel included ngine e vehicle. Costs were deducted for com ponents such as engine friction reduction, sm art cooling system s, variable valve sim pliication and the elim ination of the transmon.issi The tim ing ( V V T) , two- and three- step variable ft (valve V Vli L ) , inform ation was obtained from OEM s and suppliers a in cylinder deactivation, direct injection ( D I) , and urbochargt sim ilar way. F or the P H EV 1 0 the cost estim his report ates in t ing with engine downsiz ing. M ost of these are alrea dy in are within 5 percent of those in the P H EV report d within an 3 low- volum e production, and all could be deployed large in percent for the 2 0 2 0 to 2 0 3 0 tim e fram EV e. F 4or0thethe P H volum es in the nex t decade. In 1 5 to 2 0 years, nologies tech com m ittee’s costs are signiicantly lower: by 4 5centper for such as cam less valve actuation, continuous variabl e valve current costs and 4 2 percent for the 2 0 2 0 toim 2 0e fram 3 0 t e. lift ( CV V L ) , and hom ogeneous- charge com ition pression ign In view of the uncertainties of actual costs and how these ( H CCI) could be deployed. The conclusions hoped in for would translate as retail price eq uivalents, the di fference can connection with the deploym ent of cam less valveuation act be attributed to a difference in professional judgment. and H CCI are m ore optim istic than those anticipated for fuel A m ore dificult q uestion is the rate at which ost the of c cells in this report. The NR C energy eficiency pane l survey the battery will com e down, and what m ak es projecti ons even shows the above technologies have the potential to reduce harder is the injection of a substantial am ount ofcapital by vehicle fuel consum ption by 1 0 to 1 5 percent 0by and 2 0 by 2 the adm inistration and the enthusiasm of investors. Basically an additional 1 5 to 2 0 percent by 2 0 3 0 ( EEA K asseris , 2 0 0 7 ; there are two ways of look ing at future cost declines: and H eywood, 2 0 0 7 ; R icardo, Inc. , 2 0 0 80 ;8 and a) . NR C, 2 • P eople m ak ing these very large investm entsthinvebo hicles and lithium ion batteries m ust ex pect the rkmet a to tak e off. S ince the success of vehicle electriic ation depends on reductions in the price of battery by factors of two or three, investors and the adm inistrationust m be optim istic that large cost reductions will occur . • A m ore pessim istic perspective is that lithium on is a i well- developed technology with billions of individual cells being produced. H ow m uch im provem ent can one realistically ex n the 1 0 - year horiz on of the report? Both reports e atak fairly conservative viewpoint in term s of the cost reducti ons of batteries over tim e and, tak ing into account developm nts ine the last year, both reports m ay turn out to be overlyonservative. c

AEF ENERGY EFFICIENCY PANEL REPORT

Diesel CI Engine

Owing to high com pression ratios and reduced pum gpin losses, turbocharged diesel engines offer a 2 0 to5 2 percent eficiency advantage over gasoline S I engines when djusted a for the higher energy density of diesel fuel. The prim ary eficiency im provem ents in CI engines are lik ely m to coe from increased power density, im proved engine system agem an m ent, m ore sophisticated fuel injection system d s,imanproved com bustion processes. New ex haust after-tm treaent pecttechnologies i are em erging that reduce em issionsparticuof late m atter and ox ides of nitrogen to levels comable parto those of S I engines. One challenge for diesel engin es noted by the NR C energy eficiency panel is the added cost s and fuel econom y penalties associated with the aftertre atm ent system s for reducing these em issions ( Bandivadek et al. ar , 2 0 0 8 ; J ohnson, 2 0 0 8 ; R icardo, Inc. , 2 0 0 8 ) .

The A m erica’s Energy F uture Energy Eficiency P anel Gasoline Hybrid Electric Vehicle ex am ined the technical potential for reducing energ y dem and by im proving eficiency in transportation, lighting, heating, The prim ary eficiency beneits of a gasoline hybrid cooling, and industrial processes using ex isting chnolote electric vehicle ( H EV ) noted by the NR C energy iency efic gies, technologies developed but not yet widely utiliz ed, panel are realiz ed by elim inating idling, including regenand prospective technologies. In its report, R eal P ro sp ectserative brak ing, downsiz ing the engine, and operati ng at fo r Energ y Eficiency in the U nited States ( NA S - NA E- NR mC, ore eficient engine conditions than current S I eng ines.

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18 6

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

The NR C energy eficiency panel classiies hybrids onhow TA BL E H . 3 Ex pected Transm ission S ystem Eficiency well their electric m otor and generator function. eltB driven Im provem ents starter- generator system s elim inate engine idle reduce to fuel Transm ission Eficiency ( % ) consum ption by 4 to 6 percent. Integrated starterenerator g Current autom atic transm ission ( 4 - and 5 - speed) 9 8 4 -8 system s that recover energy from regenerative brak ing, along A utom atic transm ission ( 6 - or 7 - speed) 9 3 -9 5 with the start- stop function, can achieve a fuel consum ptio n D ual- clutch transm ission ( wet clutch) 8 6 -9 4 reduction of 1 0 to 1 2 percent. A parallel full id hybr with D ual- clutch transm ission ( dry clutch) 9 0 -9 5 power assist, such as H onda’s integrated m otorstassi system , Continuously variable transm ission 8 7 -9 0 can reduce fuel consum ption by m ore than 2 0 to ercent, 2 5 p S OU R CE: NA S - NA E- NR C ( 2 0 1 0 ) , q 2uoting 0 0R 8 )icardo, and EEA Inc. ( whereas m ore com plex system s using two m otors as such( 2 0 0 7 ) . Toyota’s hybrid synergy drive can reduce fuel consum ption m ore than 3 0 percent. S om e diesel H EV prototypes e now ar being developed. D iesel H EV s could be 1 0 percent re ef-m o icient than an eq uivalent gasoline hybrid, which translates to engine to operate near its m ax im um eficiency, urrent the c a 2 0 percent lower diesel fuel consum ption whenater grefuel estim ates of CV T eficiency are lower than the corre sponding density is factored in. A diesel H EV would beicantly signi eficiencies of 6 - or 7 - speed autom atic transms. ission CV Ts m ore ex pensive than a gasoline H EV . have been in low- volum e production for well overdecade. a Vehicle Technologies and Transmission Improvements

Summary and Costs of Potential Light-Duty Vehicle Eficiency Improvements

The NR C energy eficiency panel notes that reducing the vehicle weight by 1 0 percent is com m only though t to Table H . 4 shows plausible levels of petroleum reduc reduce fuel consum ption by 5 to 7 percent when acco m pation potential through vehicle technology im provemntse nied by appropriate engine downsiz ing to m aintain onstant c estim ated by the NR C energy eficiency panel. The CNR perform ance. P relim inary vehicle sim ulationsuggest results energy efficiency panel developed its estim ates fro m a that the relative beneits of weight reduction m ayebsm aller num ber of sources ( A n and S antini, 2 0 0 4 ; etWal. ohleck , er for som e types of hybrid vehicles ( A n and S antini, 2 0 0 4 ; 2 0 0 7 ; Cheah et al. , 2 0 0 7 ; NP C, 2 0 0 7. ;The and NR C, 2 W ohleck er et al. , 2 0 0 7 ) . In a conventional the vehicle enestim ates shown in Table H . 4 assum e that vehicle z e and si ergy used to accelerate the m ass is m ostly dissipat ed in the perform ance, such as the power- to- weight ratio and accelbrak es, while in a hybrid a signiicant fraction ofthis brak eration, are k ept constant at today’s levels. Thevolutionary e ing energy is recovered, sent back to the battery, and reused. im provem ents briely outlined above and discussedmin ore Thus weight reduction in hybrid vehicles has a m uch sm aller detail in the NR C energy eficiency panel report canreduce effect on reducing fuel consum ption than such reduc tion in the fuel consum ption of a gasoline ICE vehicle byputo 3 5 non- hybrid vehicles. A dditional weight reductionncabe percent in the nex t 2 5 years. The diesel enginerently cur achieved by vehicle redesign and downsiz ing as wellas by offers a 2 0 percent reduction in fuel consum ption veroa substituting lighter- weight m aterials in vehicle nstruction, co gasoline engine and, while the diesel engine will continue F or ex am ple, downsiz ing a passenger car by onesiz EPe-A to evolve, the gap between gasoline and diesel vehicle fuel class can reduce vehicle weight by approx im ately percent 1 0 consum ption is lik ely to narrow to a 1 5 percent rovem im p ent. ( Cheah et al. , 2 0 0 7 ) . A dditional sources nsum of fuel pco H ybrid vehicles ( including P H EV s) have a greater tentialpo tion beneits noted by the NR C energy eficiency pane l are for im provem ent and can deliver deeper reductions in vehicle from im provem ents in tires. A recent NR C report tires on fuel consum ption, although they continue to depend on and passenger vehicle fuel econom y ( NR C, 2 0 0es6 ) agre petroleum ( or alternative liq uid fuels, such ofuels) as bi . Batwith estim ates in the literature ( S churing and Fm uta ura, tery electric vehicles ( BEV s) and fuel cell vehicle s ( F CV s) 1 9 9 0 ) that the vehicle fuel consum ption willuced be red are two longer- term technologies. by 1 or 2 percent for a reduction of 0 . 0 0 1 oeficient in the c The cost estim ates developed by the NR C energy efiof rolling resistance of passenger tires—eq uivalentto a 1 0 ciency panel shown in Table H . 4 represent the appro x im ate percent reduction in overall rolling resistance. The NR C enincrem ental retail price of future vehicle system including s, ergy eficiency panel also discussed transm ission ef iciency em issions control costs, com pared to a 2 0 0 5e gasobaselin im provem ents lik ely in the nex t 1 0 to 2 0 ugh years an thro line ICE vehicle ( NH TS A , 2 0 0 7 ; EEA , 2 k0 ar 0 7 ; Bandiva increase in the num ber of gears and through im provem ents in et al. , 2 0 0 8 ) . The irst colum n shown is for z ea car; m idsi the bearings, gears, sealing elem ents, and the hydrauli c system . second colum n is for a typical pick up truck or S These U V . Table H . 3 lists the eficiency im provem ents consider ed by retail prices are based on the costs associated with producthe NR C energy eficiency panel that can be ex pected from ing a vehicle at the m anufacturing plant gate. Toccount a different transm ission system s in this tim e fram Note e. that for distribution costs and m anufacturer and dealerproit while a continuously variable transm ission ( CV T) lowsalthe m argins, production costs were m ultiplied by a or fact of

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

18 7

AP P ENDIX H

TA BL E H . 4 P lausible R eductions in P etroleum m VUehicle se froEficiency Im provem ents over the Nex earst 2and 5 Y Estim ated Increm ental Cost of A dvanced V ehicles ativeRtoela Baseline 2 0 0 5 S tandard Gasoline V ehicle P etroleum Consum ption ( gasoline eq uivalent)

Increm ental R etail P rice ( 2 0 0 7 dollars)

P ropulsion S ystem

R elative to Current Gasoline R elative to 2 0 3 5 Gasoline ICE ICE Car

Current gasoline Current diesel Current H EV 2 0 3 5 gasoline 2 0 3 5 diesel 2 0 3 5 H EV 2 0 3 5 P H EV 2 0 3 5 BEV 2 0 3 5 hydrogen F CV

1 0 .8 0 .7 5 0 .6 5 0 .5 5 0 .4 0 .2 None None

— — — 1 0 .8 5 0 .6 0 .3 — —

L ight Truck

0 1 ,7 0 0 4 ,9 0 0 2 ,0 0 0 3 ,6 0 0 4 ,5 0 0 7 ,8 0 0 1 6 ,0 0 0 7 ,3 0 0

0 2 ,1 0 0 6 ,3 0 0 2 ,4 0 0 4 ,5 0 0 5 ,5 0 0 1 0 ,5 0 0 2 4 ,0 0 0 1 0 ,0 0 0

NOTE: BEV , battery electric vehicle; F CV , fuel vehicle; cell H EV , hybrid electric vehicle; ICE, al intern com bustion engine. S OU R CE: R eport from the NR C P anel on Energy cy (Eficien NA S - NA E- NR C, 2 0 1 0 ) q uoting Bandivadek ( 2 0 0 8ar)et. al.

1 . 4 to provide representative retail price estim sate ( Evans, BIBLIOGRAPHY 2008 )The . tim escales indicated for these future technolog y A n, F . , and D . S antini. 2 0 0 4 . M asseconom im pactsies onoffuel convenvehicles are not precise. The rate of price reduction will tional vs. hybrid electric vehicles. S A E Technical P aper 2 0 0 4 - 0 1 - 0 5 7 2 depend on the deploym ent rate ( Bandivadek ar et 2al.0, 0 8 ; S A E International, W arrendale, P a. A n, F . , J . M . D eCicco, and M . H . R oss. g the2F0 uel 0 1Econom . A ssessin y Evans, 2 0 0 8 ) . P otential of L ight- D uty V ehicles. S A E International , W arrendale, P a. The results in Table H . 4 show that alternative powe rtrains Bandivadek ar, A . P . 2 0 0 8 . Evaluating the Im dvanced pact V of A ehicle and such as im proved gasoline and diesel engines and hy brids F uel Technologies in the U . S . L ight- D uty V eet.ehicle P h.FD l . thesis. entering the leet today cost from 1 0 percent topercent 3 0 M IT Engineering S ystem s D ivision, Cam bridge, M ass. m ore than a current gasoline vehicle. This price fference di Bandivadek ar, A . , K . Bodek , L . Cheah, C.Groode, Evans, J T.. H eywood, E. K asseris, K . K rom er, and M . W eiss.R 2oad 0 0in 82 .0 On 3 5the: R eis estim ated to drop to 5 percent to 1 5 percent theinm idducing Transportation’s P etroleum Consum ption and H G Em issions. term future. L onger- term options such as plugbrid in hy M assachusetts Institute of Technology ( M IT) L aboratory for Energy and and F CV s are estim ated to cost between 2 5 and rcent 3 0 pe the Environm ent, Cam bridge, M ass. J uly. m ore than a future gasoline vehicle. Battery electr ic vehicles Cheah L . , C. Evans, A . Bandivadek ar, and J . .H 2 eywood 0 0 7 . F actor of with standard vehicle perform ance and siz e rem ain ostly, c Two: H alving the F uel Consum ption of New U . S obiles . A utom by 2 0 3 5 . L F EE R eport 2 0 0 7 - 0 4 R P . Mergy IT and L aboratory the for En approaching double the cost of a future gasoline vehicle. A Environm ent. Cam bridge, M ass: M assachusetts te ofInstitu Technology. m ore plausible m ark et opportunity for BEV s is city sm all A vailable at http:/ / web. m it. edu/ sloan- auto-arch/ lab/ rese beforeh2 / iles/ cars with reduced range. H owever, these also willeed n sigcheah_ factorTwo. pdf. niicantly im proved battery perform ance and battery costs to D uleep, K . 2 0 0 7 . The H ydrogen Transition and ing A Com utom pet otive becom e com petitive. Technology. P resentation to National R esearch Counc il P anel on F uel D . C. Based on the estim ates in Table H . 4 , the NR C energy Cell V ehicles and H ydrogen on A pril 1 8 , W ashington, EEA ( Energy and Environm ental A nalysis, Inc. .) .U2 pdate 0 0 7for A deficiency panel concludes that evolutionary im prove m ents vanced Technologies to Im prove F uel Econom y oftLD igh uty V ehicles. in gasoline ICE vehicles are lik ely to prove the mst ocostD raft F inal R eport. S ubm itted to U . S . D Energy. epartm EEA ent of, effective way to reduce petroleum consum ption. eS these inc W ashington, D . C. A ugust. vehicles will be sold in large q uantities in the near term , it Evans, C. 2 0 0 8 . P utting P olicy in D rive:ng Coordinati M easures to R educe F uel U se and Greenhouse Gas Em issions from Uht-. SD . uty L ig V ehiis critical that their eficiency im provem ents are irected d cles. M . S . Thesis, Technology and P olicy P rogram une. M . assachusetts J toward reducing fuel consum ption. W hile the current hybrids Institute of Technology, Cam bridge. appear less com petitive than a com parable dieselhicle, ve H eywood, J . B. 2 0 0 7 . S trategies to R educe tion Transporta P etroleum Conthey are lik ely to becom e m ore cost com petitive r tim ovee. sum ption and Greenhouse Gas Em issions. P resentation at F reedom CA R P H EV s, BEV s, and F CV s appear to be m ore rna-costly alteand F uels P rogram M eeting. J ohnson, T. 2 0 0 8 . D iesel Em ission ControlyTechnolog in R eview. S A E tives for reducing petroleum consum ption and greenh ouse of A utom otive gas em issions. A m ong these three technologies, sPare H EV Technical P aper 2 0 0 8 - 0 1 - 0 0 6 9 . S ocietyEngineers, W arrendale, P a. A pril. lik ely to becom e available in the near to m idterm whereas , K asseris, E. P . , and J . B. H eywood. 2 0 0 7 A . Com nalysis parative of A utoBEV s and F CV s are m id- to long- term alternatives. m otive P owertrain Choices for the Nex t 2 5 Y E ears. International, S A W arrendale, P a.

.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

18 8

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

K rom er, M . A . , and J . B. H eywood. 2007rtrains: . Electric Opportunities P owe and Challenges in the U . S . L ight- D uty V ehicle . M FITleet L aboratory for Energy and the Environm ent, Cam bridge, M ass. L utsey, N. 2 0 0 8 . P rioritiz ing Clim ate Change ion AM lternatives: itigat Com paring Transportation Technologies to Options inOther S ectors. P h. D . dissertation. U niversity of California,. D M avis ay. L utsey, N. , and D . S perling. 2 0 0 5 . Energy , fuel eficiency econom y, and policy im plications. Transportation R esearch R ecord 1 9 4 1 :8 - 2 5 . NA S - NA E- NR C ( National A cadem y of S ciencesA cadem National y of Engineering- National R esearch Council) . 2 0 1 0P . rospects R eal for Energy Eficiency in the U nited S tates. The National A cadem ies P ress, W ashington, D . C. NP C ( National P etroleum Council) . 2 0 0 7 . sTechnologie for Transportation Eficiency. Topic paper of the Transportation Eficiency S ubgroup. Council Com m ittee on Global Oil and Gas. NP C, ngton, W ashi D . C. J uly. NR C ( National R esearch Council) . 2 0 0 1 . Re R eview esearch of th P rogram of the P artnership for a New Generation of V ehicles , S eventh R eport. The National A cadem ies P ress, W ashington, D . C. NR C. 2 0 0 4 . The H ydrogen Econom y: Opportunities, ts, Barriers, Cos and R & D Needs. The National A cadem ies P ress, W , D ashington . C. NR C. 2 0 0 5 . R eview of the R esearch P rogram eedomof CA the F Rr and F uel P artnership, F irst R eport. The National A cadem ress,ies WP ashington, D . C.

NR C. 2 0 0 6 . Tires and P assenger V ehicle F uel : Inform EconomingyConsum ers, Im proving P erform ance—S pecial R eport he National 2 8 6 . T A cadem ies P ress, W ashington, D . C. NR C. 2 0 0 8 a. Transitions to A lternative Transportati on Technologies—A F ocus on H ydrogen. The National A cadem ies P shington, ress, W D a . C. NR C. 2 0 0 8 b. R eview of the R esearch P rogram reedom of the CA F R and F uel P artnership: S econd R eport. The National A m cade ies P ress, W ashington, D . C. NR C. 2 0 0 9 . Transitions to A lternative Transportatio n Technologies— P lugin H ybrid Electric V ehicles. The National A cadem ies P ress, W ashington, D . C. R icardo, Inc. 2 0 0 8 . A S tudy of P otential essEffectiven of Carbon D iox ide R educing V ehicle Technologies. P repared for EP ce A ofOfi Transportation and A ir Q uality. J anuary. A vailable /at/ www. http: epa. gov/ OM S / technology/ 4 2 0 r0 8 0 0 4 a. pdf. A ccessed J uly 1 0 , 2 0 0 9 . S churing, D . , and S . F utam ura. 1 9 9 0 f. pneum R ollingatic loss highway o tires in the eighties. R ubber Chem istry and Technol ogy 6 2 ( 3 ) :3 1 5 - 3 6 7 . W eiss, M . A . , et al. 2 0 0 0 . On the R oad fe- inCycle 2 0A 2 0nalysis :A L of i New A utom obile Technologies. M assachusetts Institut e of Technology, Cam bridge, M ass. W ohleck er, R . , M . J ohannaber, and M . Espig. eterm 2ination 0 0 7of .weight D elasticity of fuel econom y for ICE, hybrid and fuel cell vehicles. S A E Technical P aper 2 0 0 7 - 0 1 - 0 3 4 3 . S A E rrendale, International, P a. W a

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

I Results of Other Major Studies

EEA ( Energy and Environm ental A nalysis, Inc. .) .Technologies 2 0 0 7 to Tables I. 1 through I. 8 , which indicate the costsd an fuel Im prove L ight- D uty V ehicle F uel Econom y.rt D to the raftNational repo consum ption beneits from other m ajor studies,ncluded are i R esearch Council Com m ittee on F uel Econom y-of DL uty ight V ehicles. here to facilitate the com parison to other sources of technoloEEA , A rlington, V a. S eptem ber. gy cost and effectiveness. H owever, the reader is ncouraged e EP A ( U . S . Environm ental P rotection A gency) P A . 2S 0taff 0 8Techni. E to look at the original source m aterial to gain etter a b undercal R eport: Cost and Effectiveness Estim ates of Tec hnologies U sed to R educe L ight- D uty V ehicle Carbon D iox ide ns.Em EP issio A 4 2 0 standing of the different assum ptions m ade in each study. F or ex am ple, som e sources consider increm ental its, bene R - 0 8 - 0 0 8 . EP A , W ashington, D . C. M artec Group, Inc. 2 0 0 8 . V ariable Costs ofnom F uely Eco Technologies. while others do not. Certain item s, such as im prove d accesP repared for A lliance of A utom obile M anufacturers. J une 1 ; am ended sories, m ay include different technologies, whichakm es an S eptem ber 2 6 and D ecem ber 1 0 . apples- to- apples com parison dificult. R etaileq price uivalent NES CCA F ( Northeast S tates Center for a Cleanture) A ir.F2 u0 0 4 . R educing Greenhouse Gas Em issions from L ight- D uty M cles. otor V M ehi arch. factors also vary from source to source, reinforcin g the need NR C ( National R esearch Council) . 2 0 0 2 . Effectivenes s and Im pact of Corto review the original m aterials as well as the tab les.

porate A verage F uel Econom y ( CA F E) S tandards. nal A Natio cadem y P ress, W ashington, D . C. R icardo, Inc. 2 0 0 8 . A S tudy of P otential essEffectiven of Carbon D iox ide REFERENCES R educing V ehicle Technologies. P repared for the. U Environm .S ental D OT/ NH TS A ( U . S . D epartm ent of Transportation/ al H ighway Nation TrafP rotection A gency, EP A 4 2 0 - R - 0 8 - 0 0 4- ,C-Contract 0 6 - 0 No. 0 3 EP , ic S afety A dm inistration) . 2 0 0 9 . A veragem F yuel S tandards, Econo W ork A ssignm ent No. 1 - 1 4 , R icardo, Inc. M , ich. A nn A rbor, P assenger Cars and L ight Truck s, M odel Y earinal 2 0R 0 ule. 1 :F 4 9 CF R S ierra R esearch. 2 0 0 8 . Basic A nalysis ofnd theLCost ong-a Term Im pact P arts 5 2 3 , 5 3 1 , 5 3 3 , 5 3 4 , 5 3 6 NH , andTS 5 3A7 -, 2D0 ock 0 9 et- No. 0 0 6of 2the, Energy Independence and S ecurity A ct F uel onom Ec y S tandards. R IN 2 1 2 7 - A K 2 9 , M arch 2 3 . W ashington D . C. S ierra R esearch, S acram ento, Calif. A pril 2 4 .

18 9

Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch T ransmission (DCT) Hybrid T echs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle T echs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

Conversion to Diesel Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory T echs Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission Techs 7.7 2.0 2.0 2.9 0.9 2.6 2.0 3.4 4.1

6.6 1.0 1.0 1.0 0.2 1.8 0.7 1.4 2.7 14.6 62.0 1.0 2.0

EPS IACC MHEV HVIA ISG CVT NAUTO DCT PSHEV 2MHEV PHEV MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

1.5 3.0

15.2 65.0

15.3

15.0

DSL DSL ADSL

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

Abbreviation

-

21.0 65.0

5.5

-

21.2 -

21.2

-

26.5 69.5

9.7

-

25.9 -

25.9

1.0 2.0

14.6 62.0

0.7 1.4 2.7

1.0 1.0 1.0 0.2 1.8

6.6 -

12.3

1.5 3.0

15.0 65.0

2.0 3.4 4.1

2.0 2.0 2.9 0.9 2.6

7.7 -

13.1

-

21.0 65.0

5.5

-

21.2 -

21.2

-

26.5 69.5

9.7

-

25.9 -

25.9

Perf. Compact Car V6 Incremental Value Net Value Low High Low High 0.5 1.0 2.0 1.0 3.0 1.0 3.0 2.5 3.0 1.0 2.0 2.0 3.0 1.0 3.0 1.5 3.5 3.9 5.5 1.0 1.5 0.5 2.6 1.0 2.6 1.9 2.9 7.0 14.0 2.1 2.2 11.0 17.0

NHTSA - 2011 Rule

1.0 2.0

13.1 61.0

0.7 1.4 2.7

1.0 1.0 3.4 0.2 1.8

5.3 -

11.1

1.5 3.0

14.6 65.0

2.0 3.4 4.1

2.0 2.0 4.0 0.6 1.9

6.5 -

12.0

-

21.0 65.0

5.5

-

20.2 -

20.2

-

26.5 69.5

9.7

-

24.9 -

24.9

Perf. Midsize Car V6 Incremental Value Net Value Low High Low High 0.5 1.0 2.0 1.0 3.0 1.0 3.0 2.5 3.0 1.0 2.0 2.0 3.0 1.0 3.0 1.5 3.5 3.9 5.5 1.0 1.5 0.5 2.6 1.0 2.6 1.9 2.9 7.0 14.0 2.1 2.2 11.0 17.0

D OT/ NH TS ) A (2 0 0 9

1.0 2.0

13.7 -

1.4 2.7

1.0 1.0 3.4 0.2 1.8

5.3 -

11.1

1.5 3.0

15.7 -

3.4 4.1

2.0 2.0 4.0 0.6 2.6

6.5 -

12.0

-

21.0 -

5.5

-

20.2 -

20.2

co ntinu ed

-

26.5 -

9.7

-

24.9 -

24.9

Perf. Large Car V8 Incremental Value Net Value Low High Low High 0.5 1.0 2.0 1.0 3.0 1.0 3.0 2.5 3.0 1.0 2.0 2.0 3.0 1.0 3.0 1.5 3.5 3.9 5.5 1.0 1.5 0.5 2.6 1.0 2.6 1.9 2.9 7.0 14.0 2.1 2.2 11.0 17.0

19 0

Low Friction Lubricants Engine Friction Reduction VVT - Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel Techs

Spark Ignition T echs

Technologies

Perf. SubcompactCar I4 Incremental Value Net Value Low High Low High 0.5 1.0 2.0 1.0 3.0 1.0 3.0 1.0 2.0 2.0 3.0 1.0 3.0 1.5 3.5 1.0 1.5 0.5 2.6 1.0 2.6 1.9 2.9 5.0 13.0 4.5 5.2 11.0 17.0

TA BL E I. 1 Technology Effectiveness, Increm ental rcent) ( PF e uel Consum ption Beneit from

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Technologies

Continued

MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

13.5 61.0

PSHEV 2MHEV PHEV

Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

0.7 1.4 5.5

CVT NAUTO DCT

Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid Techs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs 1.0 1.0 2.0

1.0 1.0 1.0 0.2 5.7

EPS IACC MHEV HVIA ISG

Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission Techs

15.0 6.6 -

DSL DSL ADSL

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

Abbreviation

2.0 1.5 3.0

13.9 63.0

2.0 3.4 7.5

2.0 2.0 2.9 0.9 6.5

15.3 7.7 -

-

23.0 65.0

8.2

-

21.2 21.2 -

-

28.5 69.5

12.9

-

25.9 25.9 -

Subcompact Car I4 Incremental Value Net Value Low High Low High 0.5 1.0 2.0 1.0 3.0 1.0 3.0 1.0 2.0 2.0 3.0 1.0 3.0 1.5 3.5 1.0 1.5 0.5 2.6 1.0 2.6 1.9 2.9 5.0 13.0 4.5 5.2 11.0 17.5

Conversion to Diesel Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory Techs

Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel Techs

Spark Ignition Techs

TA BL E I. 1

1.0 1.0 2.0

13.5 61.0

0.7 1.4 5.5

1.0 1.0 1.0 0.2 5.7

15.0 6.6 -

2.0 1.5 3.0

13.9 63.0

2.0 3.4 7.5

2.0 2.0 2.9 0.9 6.5

15.3 7.7 -

-

23.0 65.0

8.2

-

21.2 21.2 -

-

28.5 69.5

12.9

-

25.9 25.9 -

Compact Car I4 Incremental Value Net Value Low High Low High 0.5 1.0 2.0 1.0 3.0 1.0 3.0 1.0 2.0 2.0 3.0 1.0 3.0 1.5 3.5 1.0 1.5 0.5 2.6 1.0 2.6 1.9 2.9 5.0 13.0 4.5 5.2 11.0 17.5

NHTSA - 2011 Rule

1.0 1.0 2.0

1 1.8 60.0

0.7 1.4 2.7

1.0 1.0 3.4 0.2 5.7

13.8 5.3 -

2.0 1.5 3.0

12.8 63.0

2.0 3.4 4.1

2.0 2.0 4.0 0.6 6.5

14.2 6.5 -

-

23.0 65.0

5.5

-

20.2 20.2 -

-

28.5 69.5

9.7

-

24.9 24.9 -

Midsize Car I4 Incremental Value Net Value Low High Low High 0.5 1.0 2.0 1.0 3.0 1.0 3.0 1.0 2.0 2.0 3.0 1.0 3.0 1.5 3.5 1.0 1.5 0.5 2.6 1.0 2.6 1.9 2.9 5.0 13.0 4.5 5.2 11.0 17.5

1.0 1.0 2.0

11.8 -

0.7 1.4 2.7

1.0 1.0 3.4 0.2 5.7

11.1 5.3 -

2.0 1.5 3.0

12.8 -

2.0 3.4 4.1

2.0 2.0 4.0 0.6 6.5

12.0 6.5 -

-

23.0 -

5.5

-

20.2 20.2 -

AP P ENDIX I co ntinu ed

-

28.5 -

9.7

-

24.9 24.9 -

Large Car V6 Incremental Value Net Value Low High Low High 0.5 1.0 2.0 1.0 3.0 1.0 3.0 2.5 3.0 1.0 2.0 2.0 3.0 1.0 3.0 1.5 3.5 3.9 5.5 1.0 1.5 0.5 2.6 1.0 2.6 1.9 2.9 5.0 13.0 2.1 2.2 11.0 17.5

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

19 1

T echnologies

Continued

Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance T ires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. T rans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid T echs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

PSHEV 2MHEV PHEV

CVT NAUTO DCT

EPS IACC MHEV HVIA ISG

DSL DSL ADSL

Conversion to Diesel

Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory T echs Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission T echs

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

Abbreviation

6.5 2.0 2.0 4.0 0.6 6.5 2.0 3.4 4.1 12.8 2.0 1.5 3.0

5.3 1.0 1.0 3.4 0.2 5.7 0.7 1.4 2.7 11.8 1.0 1.0 2.0

5.5 23.0 -

20.2 9.7 28.5 -

24.9

Minivan L T V6 Incremental Value Net Value Low High Low High 0.5 1.0 2.0 1.0 3.0 1.0 3.0 2.5 3.0 1.0 2.0 2.0 3.0 1.0 3.0 1.5 3.5 3.9 5.5 1.0 1.5 0.5 2.6 1.0 2.6 1.9 2.9 7.0 14.0 2.1 2.2 11.0 17.5 11.1 12.0 20.2 24.9 1.0 1.0 1.0 0.2 5.7 0.7 1.4 2.7 13.5 1.5 61.0 1.0 1.0 2.0

5.3 2.0 2.0 2.9 0.9 6.5 2.0 3.4 4.1 13.9 4.3 63.0 2.0 1.5 3.0

6.5 5.5 23.0 17.5 65.0 -

20.2 9.7 28.5 21.0 69.5 -

24.9

Net Value Low High 4.5 13.0 11.0 17.5 20.2 24.9

Small LT I4

Incremental Value Low High 0.5 1.0 2.0 1.0 3.0 1.0 3.0 1.0 2.0 2.0 3.0 1.0 3.0 1.5 3.5 1.0 1.5 0.5 2.6 1.0 2.6 1.9 2.9 4.5 5.2 13.8 14.2

NHTSA - 2011 Rule

1.0 0.5 1.0 2.0

1.0 3.4 0.2 5.7 1.4 2.7 13.3 0.3 -

4.0

0.4 0.4 1.0

2.0 1.0 1.5 3.0

2.0 4.0 0.6 6.5 3.4 4.1 16.2 2.9 -

6.5

5.5 23.0 17.5 -

20.2

9.7 28.5 21.0 -

23.9

Net Value Low High 7.0 14.0 11.0 17.5 20.2 23.9

Midsize LT V6

Incremental Value Low High 0.5 1.0 2.0 1.0 3.0 1.0 3.0 2.5 3.0 1.0 2.0 2.0 3.0 1.0 3.0 1.5 3.5 3.9 5.5 1.0 1.5 0.5 2.6 1.0 2.6 1.9 2.9 2.1 2.2 9.9 12.0

0.5 1.0 2.0

1.4 2.7 7.9 -

4.0

0.4 0.4 1.0

1.0 1.5 3.0

3.4 4.1 8.7 -

5.3

5.5 13.5 -

19.2

9.7 17.0 -

23.9

Net Value Low High 7.0 14.0 11.0 17.5 19.2 23.9

Large LT V8

Incremental Value Low High 0.5 1.0 2.0 1.0 3.0 1.0 3.0 2.5 3.0 1.0 2.0 2.0 3.0 1.0 3.0 1.5 3.5 3.9 5.5 1.0 1.5 0.5 2.6 1.0 2.6 1.9 2.9 2.1 2.2 10.0 10.9

19 2

Low Friction Lubricants Engine Friction Reduction VVT - Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) T urbocharging and Downsizing Diesel Techs

Spark Ignition T echs

TA BL E I. 1

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

19 3

AP P ENDIX I

TA BL E I. 2 Technology Effectiveness, Increm ental rcent) ( PF e uel Consum ption Beneit from

NR C ( 2 0 0 2 )

NRC - 2002 Technologies Spark Ignition Techs Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel Techs Conversion to Diesel Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory Techs Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission Techs Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid Techs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

Abbreviation

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS DSL DSL ADSL EPS IACC MHEV HVIA ISG CVT NAUTO DCT PSHEV 2MHEV PHEV MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

Low

High 5.0 2.0 2.0 3.0 3.0 2.0 2.0 6.0 3.0 2.0 7.0

AVG 1.0 3.0 1.5 1.5 2.5 2.5 1.5 1.5 4.5 2.5 1.5 6.0

-

-

2.5 2.0 7.0

2.0 1.5 5.5

8.0 2.0 5.0

6.0 1.5 4.0

-

-

1.5 -

1.3 -

1.0 1.0 1.0 1.0 2.0 2.0 1.0 1.0 3.0 2.0 1.0 5.0 Non-incremental Non-incremental 1.5 1.0 4.0 Non-incremental 4.0 1.0 3.0 Non-incremental Non-incremental 1.0 -

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

19 4

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

TA BL E I. 3 Technology Effectiveness, Increm ental rcent) ( PF e uel Consum ption Beneit from

EPA 2008 Technologies Spark Ignition Techs

Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory Techs Electric Power Steering (EPS) Improved Accessories2 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission Techs Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid Techs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle T echs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

DSL

25.0

35.0

DSL ADSL

-

-

-

-

-

-

1.5 1.5 30.0 6.0 5.3 12.0 35.0 58.0 1.5 1.0 -

1.5 1.0 25.0 6.0 4.5 9.5 35.0 40.0 58.0 1.0 1.0 -

2.0 2.0 6.0 14.5 2.0 -

1.8 1.5 25.0 6.0 5.3 12.0 35.0 40.0 58.0 1.5 1.0 -

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

Conversion to Diesel

3 3 3

Large Car V6 AVG 0.5 2.0 3.0 4.0 2.0 3.0 4.0 5.0 3.0 4.0 1.5 6.0 30.0

Abbreviation

Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing 1 Diesel T echs

Small Car I4

EP A ( 2 0 0 8 )

Low

High 0.5

1.0 3 3.0 4.0 2.0 3.0 4.0 5.0 3.0 4.0 1.0 2.0 5.0 7.0 Non-incremental

Non-incremental EPS 1.5 IACC 1.0 2.0 MHEV HVIA ISG 30.0 Non-incremental 6.0 CVT NAUTO 4.5 6.0 DCT 9.5 14.5 Non-incremental PSHEV 35.0 2MHEV PHEV 58.0 Non-incremental MR1 MR2 MR5 MR10 MR20 ROLL 1.0 2.0 LDB SAX 1.0 AERO -

1.0 4.0 3.0 6.0 1.0 4.0 3.0 6.0 6.0 4.0 4.0 1.0 5.0 30.0

3 2.0 7.0 40.0

AVG 0.5 2.0 4.0 3.0 6.0 1.0 4.0 3.0 6.0 6.0 4.0 4.0 1.5 6.0 35.0

Low

High 0.5

2.0 -

DSL

Conversion to Diesel

Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory Techs Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission Techs

Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid Techs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

3.0 6.7

3.0 8.0 -

EPS IACC MHEV HVIA ISG CVT NAUTO DCT PSHEV 2MHEV PHEV MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO 1.3 -

-

-

-

DSL ADSL

2.0

from report for NAS 1.5 -

Abbreviation

from EPA report

Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel Techs

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

Spark Ignition Techs

Technologies

Standard Car I4, 2.4L-4V, DCP, 5spd AT, 3.39 FDR

-

-

-

-

-

-

-

Low -

-

-

7.0

-

-

-

-

5.0 3.0 2.0 -

2.0

from EPA report

1.3 -

-

-

-

-

-

-

from report for NAS -

Full Size Car V6, 3.5L-4V, 5spd AT, 2.87 FDR

-

-

-

3.0 -

-

-

-

2.0 -

-

AP P ENDIX I

1.6 -

-

6.8

1.7 -

-

-

12.8

1.9 -

-

6.4

1.4 -

-

-

-

from report for NAS (pack 5) (pack 15) 4.4

-

-

2.0 -

-

-

-

-

5.0 3.0 3.0

2.0

from EPA report

1.4 -

-

2.4 -

2.0 -

-

-

-

from report for NAS 4.0 2.5 2.8 -

Large MPV V6, 3.8L-2V, OHV, 4spd AT, 3.43 FDR

2.0

-

9.0

-

-

-

16.0

-

2.0

from EPA report

1.4

-

9.3

-

-

-

11.4

from report for NAS -

Truck V8, 5.4L-3V, CCP, 4spd AT, 3.73 FDR

co ntinu ed

R icardo, 2 0Inc. 0 8( ) , NES CCA F ( 2 0 0 4 ) , S ierra R esearch ( 2 0 0

Small MPV I4, 2.4L-4V, DCP, 4spd AT, 3.91 FDR

from EPA report

Ricardo, Inc.

TA BL E I. 4 Technology Effectiveness, Increm ental rcent) ( peF uel Consum ption Beneit from EEA ( 2 0 0 7 )

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

19 5

Continued

Technologies

Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid Techs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs

DSL ADSL

Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory Techs Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission Techs

MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

PSHEV 2MHEV PHEV

CVT NAUTO DCT

EPS IACC MHEV HVIA ISG

DSL

Conversion to Diesel

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

Abbreviation

0.5 0.5 4.0 4.0 6.0 1.0 4.0 4.0 6.0 6.0 4.0 1.0 8.0 15.0 3.0 3.0 7.0 53.0 -

0.5 0.5 3.0 4.0 2.0 3.0 4.0 5.0 4.0 0.0 6.0 13.0 1.0 3.0 1.0 4.0 3.0 8.0 53.0 0.5 1.0 2.6 5.3 1.8 1.7

Large

Car V6

NESCCAF

Small

Car I4

18.0 4.0 3.0 8.0 53.0 -

-

0.5 0.5 2.0 3.0 5.0 1.0 2.0 3.0 4.0 5.0 3.0 -1.0 6.0 -

Mini

V an V6

21.0 3.0 8.0 53.0 -

-

0.5 0.5 2.0 4.0 6.0 1.0 3.0 4.0 5.0 6.0 4.0 -1.0 6.0 -

Small

T ruck/SUV V6

17.0 1.0 2.0 0.0 2.0 5.0 53.0 0.6 1.1 2.9 5.7 2.0 1.9

-

0.5 0.5 4.0 4.0 4.0 2.0 4.0 4.0 5.0 4.0 4.0 0.0 -

Large Truck/SUV V8

co ntinu ed

19 6

Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel Techs

Spark Ignition Techs

TA BL E I. 4

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

19 7

AP P ENDIX I

TA BL E I. 4

Continued

Sierra Research Technologies

Midsize

Truck

- assume engine size adj.

for constant acceleration

Spark Ignition Techs Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel Techs Conversion to Diesel Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory Techs Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission Techs Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid Techs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

Abbreviation

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

0.5 7.5 6.3 11.4 7.5 5.9 -0.3

0.5 8.8 6.8 12.4 8.8 6.2 0.3

DSL DSL ADSL

21.3

18.6

-

-

EPS IACC MHEV HVIA ISG

1.8 0.9 -

1.1 0.6 -

CVT NAUTO DCT

4.0

4.4

PSHEV 2MHEV PHEV

28.7 -

22.1 -

MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

-

-

co ntinu ed

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

19 8 TA BL E I. 4

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Continued

EEA -constant engine size

T echnologies Spark Ignition Techs Low Friction Lubricants Engine Friction Reduction VVT - Coupled Cam Phasing (CCP), SOHC Discrete V ariable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete V ariable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete V ariable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel Techs

Values were converted to FC%

percent relative to PFI, fixed valve timing

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

Low 0.9 1.8 1.3 n/a 5.3 1.1 1.8 2.9 6.5 5.3 1.3 n/a n/a 2.9 n/a

High 1.1 6.0 1.9 n/a 7.1 1.8 2.5 3.8 8.3 7.1 1.9 n/a n/a 3.8 n/a

AVG 1.0 3.9 1.6 n/a 6.2 1.4 2.2 3.4 7.4 6.2 1.6 n/a n/a 3.4 n/a

Abbreviation

DSL

24.8

30.1

n/a

Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory Techs

DSL ADSL

n/a

n/a

n/a

n/a

n/a

n/a

Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission Techs

EPS IACC MHEV HVIA ISG

1.8 n/a 4.0 0.3 2.9

2.2 n/a 4.6 0.7 11.5

2.0 n/a 4.3 0.5 7.2

Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid Techs

CVT NAUTO DCT

4.8 4.0 6.1

7.8 5.5 7.0

6.3 4.8 6.5

Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle T echs

PSHEV 2MHEV PHEV

-

-

-

MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

n/a n/a 3.0 5.8 1.3 n/a n/a 1.8 3.5

n/a n/a 3.2 6.2 1.5 n/a n/a 2.2 4.2

n/a n/a 3.1 6.0 n/a n/a n/a 3.8

Conversion to Diesel

Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

Technologies

Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid Techs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

Conversion to Diesel Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory Techs Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission T echs 120.0 211.0 -

105.0 173.0 372.0 84.0 1713.0 300.0 323.0 68.0 1409.0 19648.0 6.0 117.0 60.0

EPS IACC MHEV HVIA ISG CVT NAUTO DCT PSHEV 2MHEV PHEV MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

9.0 116.0

1462.0 19701.0

3254.0 1858.0 -

2963.0 1567.0 -

196.0 440.0 -

5.0

High

7.5 117.0 88.0

1435.5 19674.5

300.0 323.0 68.0

-

4300.0 22500.0

500.0

-

-

112.5 192.0 372.0 84.0 1713.0

4000.0 4000.0

Net -

3108.5 1712.5

AVG 5.0 124.0 61.0 201.0 61.0 61.0 201.0 306.0 61.0 201.0 373.0 366.5 1223.0

6.0 117.0 60.0

1742.0 23670.0

9.0 116.0

1795.0 23723.0

-

300.0 323.0 68.0

1858.0 -

3254.0

196.0 440.0 -

120.0 211.0 -

5.0

High

105.0 173.0 408.0 84.0 2019.0

1567.0 -

2963.0

52.0 61.0 201.0 61.0 61.0 201.0 306.0 61.0 201.0 373.0 293.0 1223.0

Low

7.5 117.0 88.0

1768.5 23696.5

300.0 323.0 68.0

112.5 192.0 408.0 84.0 2019.0

-

3108.5 1712.5

AVG 5.0 124.0 61.0 201.0 61.0 61.0 201.0 306.0 61.0 201.0 373.0 366.5 1223.0

I4

I4

52.0 61.0 201.0 61.0 61.0 201.0 306.0 61.0 201.0 373.0 293.0 1223.0

Low

Compact Car

Subcompact Car

NHTSA 2011

D OT/9NH ) TS A ( 2 0 0

DSL DSL ADSL

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

Abbreviation

Increm ental Costs ( $ ) from

Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel T echs

Spark Ignition T echs

TA BL E I. 5

-

4900.0 26700.0

500.0

-

-

4000.0 4000.0

Net -

6.0 117.0 60.0

2175.0 26702.0

300.0 323.0 218.0

105.0 173.0 453.0 84.0 2190.0

1567.0 -

2963.0

52.0 61.0 201.0 61.0 61.0 201.0 306.0 61.0 201.0 373.0 293.0 1223.0

Low 5.0

9.0 116.0

2228.0 26755.0

-

120.0 211.0 -

1858.0 -

3254.0

196.0 440.0 -

High

I4

7.5 117.0 88.0

2201.5 26728.5

300.0 323.0 218.0

112.5 192.0 453.0 84.0 2190.0

-

3108.5 1712.5

AVG 5.0 124.0 61.0 201.0 61.0 61.0 201.0 306.0 61.0 201.0 373.0 366.5 1223.0

Midsize Car

-

5600.0 30000.0

600.0

-

-

4000.0 4000.0

Net -

6.0 117.0 60.0

2534.0 -

300.0 323.0 218.0

105.0 173.0 490.0 84.0 2386.0

3110.0 -

4105.0

78.0 122.0 306.0 75.0 122.0 122.0 306.0 432.0 306.0 122.0 76.0 590.0 384.0 822.0

Low 5.0

9.0 116.0

2587.0 -

-

3495.0 120.0 211.0 -

4490.0

294.0 558.0 -

High

V6

7.5 117.0 88.0

2560.5 -

300.0 323.0 218.0

112.5 192.0 490.0 84.0 2386.0

-

4297.5 3302.5

AVG 5.0 186.0 122.0 306.0 75.0 122.0 122.0 306.0 432.0 306.0 122.0 76.0 590.0 471.0 822.0

Large Car

AP P ENDIX I co ntinu ed

-

6200.0 -

600.0

-

-

5600.0 5600.0

Net -

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

19 9

300.0 323.0 97.0 2838.0 23736.0 117.0 60.0

PSHEV 2MHEV PHEV MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

105.0 173.0 406.0 84.0 1789.0

EPS IACC MHEV HVIA ISG CVT NAUTO DCT

-

-

Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. T rans. with Improved Internals Dual Clutch T ransmission (DCT) Hybrid T echs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance T ires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

1858.0

1567.0

116.0

2966.0 23864.0

638.0 218.0 5900.0 26800.0 -

2902.0 23800.0 117.0 88.0

600.0

-

-

300.0 480.5 157.5

4000.0

1712.5

-

4000.0

3108.5

112.5 192.0 406.0 84.0 1826.5

Net -

AVG 5.0 124.0 61.0 201.0 61.0 61.0 201.0 306.0 61.0 201.0 373.0 366.5 1223.0

117.0 60.0

3144.0 26790.0

300.0 323.0 97.0

116.0

3197.0 26843.0

638.0 218.0

120.0 211.0 -

105.0 173.0 443.0 84.0 2054.0

3495.0

4490.0

294.0 558.0 -

-

5.0

High

-

3110.0

4105.0

78.0 122.0 306.0 75.0 122.0 122.0 306.0 432.0 306.0 122.0 76.0 590.0 384.0 822.0

Low

117.0 88.0

3170.5 26816.5

300.0 480.5 157.5

112.5 192.0 443.0 84.0 2054.0

-

3302.5

4297.5

AVG 5.0 186.0 122.0 306.0 75.0 122.0 122.0 306.0 432.0 306.0 122.0 76.0 590.0 471.0 822.0

-

6400.0 30100.0

600.0

-

-

5600.0

5600.0

Net -

117.0 60.0

4093.0 30110.0

300.0 323.0 97.0

105.0 173.0 494.0 84.0 2183.0

-

3110.0

4105.0

78.0 122.0 306.0 75.0 122.0 122.0 306.0 432.0 306.0 122.0 76.0 590.0 384.0 822.0

Low 5.0

116.0

4146.0 30163.0

638.0 218.0

120.0 211.0 -

-

3495.0

4490.0

294.0 558.0 -

High

V6

117.0 88.0

4119.5 30136.5

300.0 480.5 157.5

112.5 192.0 494.0 84.0 2183.0

-

3302.5

4297.5

AVG 5.0 186.0 122.0 306.0 75.0 122.0 122.0 306.0 432.0 306.0 122.0 76.0 590.0 471.0 822.0

Performance Midsize Car

-

7500.0 33600.0

600.0

-

-

5600.0

5600.0

Net -

117.0 60.0

5467.0 -

323.0 97.0

105.0 173.0 549.0 84.0 2351.0

-

3723.0

5125.0

104.0 122.0 396.0 75.0 122.0 122.0 396.0 582.0 400.0 122.0 76.0 746.0 512.0 1229.0

Low 5.0

116.0

5520.0 -

638.0 218.0

120.0 211.0 -

4215.0

5617.0

392.0 744.0 -

High

V8

117.0 88.0

5493.5 -

480.5 157.5

112.5 192.0 549.0 84.0 2351.0

-

3969.0

5371.0

AVG 5.0 248.0 122.0 396.0 75.0 122.0 122.0 396.0 582.0 400.0 122.0 76.0 746.0 628.0 1229.0

-

8800.0 -

600.0

-

-

7000.0

7000.0

Net -

co ntinu ed

Performance Large Car

2 0 0

120.0 211.0 1864.0

3254.0

2963.0

DSL DSL ADSL

Conversion to Diesel

Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory T echs Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission Techs

5.0

High 196.0 440.0 -

Low

V6

52.0 61.0 201.0 61.0 61.0 201.0 306.0 61.0 201.0 373.0 293.0 1223.0

Abbreviation

Performance Compact Car

I4

NHTSA 2011 Performance Subcompact Car

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

T echnologies

Continued

Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) T urbocharging and Downsizing Diesel Techs

Spark Ignition Techs

TA BL E I. 5

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Technologies

Continued

Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid T echs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

300.0 323.0 218.0 2534.0 6.0 117.0 60.0

CVT NAUTO DCT PSHEV 2MHEV PHEV MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

105.0 173.0 490.0 84.0 2386.0

EPS IACC MHEV HVIA ISG

9.0 116.0

2587.0 -

-

120.0 211.0 -

-

-

4490.0 3495.0

4105.0 3110.0

DSL DSL ADSL

294.0 558.0 -

5.0

600.0

300.0 323.0 218.0

7.5 117.0 88.0

-

6200.0 -

-

112.5 192.0 490.0 84.0 2386.0

2560.5 -

5600.0 5600.0 -

4297.5 3302.5 -

Net -

AVG 5.0 186.0 122.0 306.0 75.0 122.0 122.0 306.0 432.0 306.0 122.0 76.0 590.0 471.0 822.0

6.0 117.0 60.0

1932.0 6376.0 24376.0

300.0 323.0 97.0

105.0 173.0 427.0 84.0 2029.0

-

2963.0 1567.0

52.0 61.0 201.0 61.0 61.0 201.0 306.0 61.0 201.0 373.0 293.0 1223.0

Low 5.0

9.0 116.0

1985.0 6429.0 24329.0

638.0 218.0

120.0 211.0 -

-

3254.0 1858.0

196.0 440.0 -

High

7.5 117.0 88.0

1958.5 6402.5 24352.5

300.0 480.5 157.5

112.5 192.0 427.0 84.0 2029.0

1712.5 -

3108.5

AVG 5.0 124.0 61.0 201.0 61.0 61.0 201.0 306.0 61.0 201.0 373.0 366.5 1223.0

I4

High

Small LT

V6

NHTSA 2011 Minivan LT

78.0 122.0 306.0 75.0 122.0 122.0 306.0 432.0 306.0 122.0 76.0 590.0 384.0 822.0

Low

Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory Techs Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission T echs

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

Abbreviation

Conversion to Diesel

Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel T echs

Spark Ignition T echs

TA BL E I. 5

-

5200.0 9800.0 27500.0

600.0

-

4000.0 -

4000.0

Net -

1.0 1.0 2.0 6.0 89.0 117.0 60.0

3173.0 8313.0 -

323.0 97.0

105.0 502.0 84.0 2457.0

-

4105.0 3110.0

78.0 122.0 306.0 75.0 122.0 122.0 306.0 432.0 306.0 122.0 76.0 590.0 384.0 822.0

Low 5.0

2.0 2.0 4.0 9.0 116.0

3188.0 8328.0 -

638.0 218.0

120.0 -

-

4490.0 3495.0

294.0 558.0 -

High

V6

1.5 1.5 3.0 7.5 89.0 117.0 88.0

3180.5 8320.5 -

480.5 157.5

112.5 502.0 84.0 2457.0

3302.5 -

4297.5

AVG 5.0 186.0 122.0 306.0 75.0 122.0 122.0 306.0 432.0 306.0 122.0 76.0 590.0 471.0 822.0

Midsize LT

-

6400.0 12100.0 -

600.0

-

5600.0 -

5600.0

Net -

1.0 1.0 2.0 89.0 117.0 60.0

14106.0 -

323.0 97.0

-

-

5125.0 3723.0

104.0 122.0 396.0 75.0 122.0 122.0 396.0 582.0 400.0 122.0 76.0 746.0 512.0 1229.0

Low 5.0

2.0 2.0 4 116.0

15171.0 -

638.0 218.0

-

-

5617.0 4215.0

392.0 744.0 -

High

V8

1.5 1.5 3.0 89.0 117.0 88.0

14638.5 -

480.5 157.5

-

3969.0 -

5371.0

AVG 5.0 248.0 122.0 396.0 75.0 122.0 122.0 396.0 582.0 400.0 122.0 76.0 746.0 628.0 1229.0

Large LT

-

15300.0 -

600.0

-

7000.0 -

7000.0

Net -

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

AP P ENDIX I

2 0 1

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 0 2 TA BL E I. 6

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Increm ental Costs ( $ ) from

NR C ( 2 0 0 2 )

NRC 2002 Technologies Spark Ignition Techs Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel Techs

Abbreviation

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

Low

High -

35.0 35.0 70.0 112.0 35.0 35.0 70.0 112.0 35.0 70.0 350.0

140.0 140.0 120.0 252.0 140.0 140.0 120.0 252.0 140.0 120.0 560.0

AVG 87.5 87.5 95.0 182.0 87.5 87.5 95.0 182.0 87.5 95.0 455.0

DSL

-

-

-

Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory Techs

DSL ADSL

-

-

-

-

-

-

Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission Techs

EPS IACC MHEV HVIA ISG

105.0 84.0 210.0

150.0 112.0 350.0

127.5 98.0 280.0

CVT NAUTO DCT

140.0 140.0 70.0

350.0 280.0 280.0

245.0 210.0 175.0

PSHEV 2MHEV PHEV

-

-

-

MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

210.0 14.0 0.0

350.0 56.0 140.0

280.0 35.0 70.0

Conversion to Diesel

Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid Techs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

2790 118 2477

DSL DSL ADSL EPS IACC MHEV HVIA ISG

Conversion to Diesel

Continuously V ariable T ransmission (CVT) 6/7/8-Speed Auto. T rans. with Improved Internals Dual Clutch T ransmission (DCT) Hybrid T echs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle T echs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance T ires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10% 231 76 141 3754 4500 6 676 -

CVT NAUTO DCT PSHEV 2MHEV PHEV MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory T echs Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission T echs

Low Friction Lubricants Engine Friction Reduction VVT - Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously V ariable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) T urbocharging and Downsizing Diesel T echs

Low 3 0 59 169 59 89 169 254 59 169 122 690

T echnologies

Increm ental Costs ( $ ) from

Abbreviation

Spark Ignition T echs

TA BL E I. 7

-

-

167 -

197 -

-

-

High 84 420 -

6 676 -

3754 4500

231 121.5 141

157.5 2477

2790 -

A VG 3 42 59 169 59 89 169 254 59 169 271 690

6 676 -

4655 6750

270 76 141

118 3153

-

3045

Low 3 0 119 246 203 119 209 246 466 203 59 246 204 120

-

-

167 -

197 -

-

-

High 126 525 -

V6

I4

EPA Large Car

Small Car

EP A ( 2 0 0 8 )

6 676 -

4655 6750

270 121.5 141

157.5 3153

3045 -

A VG 3 63 119 246 203 119 209 246 466 203 59 246 364.5 120

6 676 0

4655 6750

270 76 141

118 -

-

3120

Low 3 0 119 246 203 119 209 246 466 203 59 246 204 120

75

-

167 -

197 -

-

-

High 126 525 -

V6

Minivan

6 676 37.5

4655 6750

270 121.5 141

157.5 -

3120 -

A VG 3 63 119 246 203 119 209 246 466 203 59 246 364.5 120

6 87 676 0

4655 6750

76 141

118 -

-

3405

Low 3 0 119 246 203 119 209 246 466 203 59 246 204 120

75

-

167 -

197 -

-

-

High 126 525 -

V6

Small Truck

6 87 676 37.5

4655 6750

121.5 141

157.5 -

3405 -

AVG 3 63 119 246 203 119 209 246 466 203 59 246 364.5 120

6 87 0

6006 10200

76 141

118 -

-

4065

Low 3 0 119 322 229 119 209 322 508 229 59 322 228 810

75

-

167 -

197 -

-

-

High 168 525 -

V8

Large Truck

6 87 37.5

6006 10200

121.5 141

157.5 -

4065 -

AVG 3 84 119 322 229 119 209 322 508 229 59 322 376.5 810

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

AP P ENDIX I

2 0 3

T echnologies

Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid T echs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid V ehicle T echs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

225 190 195 100 380 18 23

CVT NAUTO DCT PSHEV 2MHEV PHEV MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

75 320 16 -

140 440 22 33

-

255 325 225

85 380 18 -

-

EPS IACC MHEV HVIA ISG

-

-

-

-

DSL DSL ADSL

Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory T echs Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator T ransmission T echs

-

I4 High 18 60 54 54 84 158 346 94 155 520

Low 14 18 50 50 76 142 314 82 145 480

Conversion to Diesel

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

Abbreviation

120 410 20 28

-

240 258 210

80 350 17 -

-

-

2200.0

AVG 16 39 52 52 80 150 330 88 150 500

-

-

100 380 18 23

-

360 190 195

140 440 22 33

-

400 325 225

85 380 18 -

-

-

75 320 16 -

-

-

I-6 High 23 85 54 318 54 84 212 420 318 140 207 580

Low 17 23 50 302 50 76 188 380 302 120 193 540

120 410 20 28

-

380 258 210

80 350 17 -

-

-

-

A VG 20 54 52 310 52 80 200 400 310 130 200 560

100 380 18 23

-

360 190 195

75 320 16 -

-

-

-

Low 17 23 100 302 100 178 198 440 302 120 193 550

140 440 22 33

-

400 325 225

85 380 18 -

-

-

-

High 23 85 108 318 108 190 222 480 318 140 207 610

V6

120 410 20 28

-

380 258 210

80 350 17 -

-

-

3200.0

AVG 20 54 104 310 104 184 210 460 310 130 200 580

100 380 18 23

-

360 190 195

75 320 16 -

-

-

-

Low 20 27 100 205 100 178 255 575 205 144 240 630

140 440 22 33

-

400 325 225

85 380 18 -

-

-

High 28 88 108 225 108 190 285 625 225 170 260 690

V8

co ntinu ed

120 410 20 28

-

380 258 210

80 350 17 -

-

-

-

A VG 24 58 104 215 104 184 270 600 215 157 250 660

EEA ( 2 rra 0 0R 7esearch ) , S ie ( 2 0 0 8 ) , M artec ( 2 0 0 8 ) , and NES CCA

2 0 4

Low Friction Lubricants Engine Friction Reduction VVT - Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel T echs

Spark Ignition T echs

EEA

TA BL E I. 8 Technology Effectiveness, Increm ental rcent) ( PF e uel Consum ption Beneit from (2 0 0 4 )

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 0 5

AP P ENDIX I

TA BL E I. 8

Continued

Sierra Research Midsize

Truck

Low 13 335 335 515 814

Low 16 410 410 630 996

DSL ADSL

5775 -

7063 -

EPS IACC MHEV HVIA ISG

76 68 -

140 83 -

CVT NAUTO DCT

450

551

PSHEV 2MHEV PHEV

-

-

MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

-

-

Technologies Spark Ignition Techs Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel Techs Conversion to Diesel Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory Techs Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission Techs Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid Techs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

Abbreviation

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS DSL

co ntinu ed

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 0 6

ASSESSMENT OF F U EL ECONOMY TECH NOLOGIES F OR ULIGH TY VT- EH D ICLES

TA BL E I. 8

Continued

Martec Research MPFI, DOHC, 4V

MPFI, DOHC, 4V

MPFI, DOHC, 4V

L4

V6

V8

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

428 440 -

480 675 558 855

825 746 1289

Technologies Spark Ignition Techs Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel Techs

Abbreviation

DSL

-

-

-

Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory Techs

DSL ADSL

-

3542 -

5198 -

Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission Techs

EPS IACC MHEV HVIA ISG

627 617

-

-

CVT NAUTO DCT

638 450

638 450

638 450

PSHEV 2MHEV PHEV

5246 -

7871 -

9681 -

MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

-

-

-

Conversion to Diesel

Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid Techs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

co ntinu ed

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 0 7

AP P ENDIX I

TA BL E I. 8

Continued

NESCCAF Large Car

Technologies Spark Ignition Techs Low Friction Lubricants Engine Friction Reduction VVT- Coupled Cam Phasing (CCP), SOHC Discrete Variable Valve Lift (DVVL), SOHC Cylinder Deactivation, SOHC VVT - In take Cam Phasing (ICP) VVT - Dual Cam Phasing (DCP) Discrete Variable Valve Lift (DVVL), DOHC Continuously Variable Valve Lift (CVVL) Cylinder Deactivation, OHV VVT - Coupled Cam Phasing (CCP), OHV Discrete Variable Valve Lift (DVVL), OHV Conversion to DOHC with DCP Stoichiometric Gasoline Direct Injection (GDI) Turbocharging and Downsizing Diesel Techs Conversion to Diesel Conversion to Diesel following TRBDS Conversion to Advanced Diesel Electrification/Accessory Techs Electric Power Steering (EPS) Improved Accessories 12V BAS Micro-Hybrid Higher Voltage/Improved Alternator Integrated Starter Generator Transmission Techs Continuously Variable Transmission (CVT) 6/7/8-Speed Auto. Trans. with Improved Internals Dual Clutch Transmission (DCT) Hybrid Techs Power Split Hybrid 2-Mode Hybrid Plug-in hybrid Vehicle Techs Mass Reduction - 1% Mass Reduction - 2% Mass Reduction - 5% Mass Reduction - 10% Mass Reduction - 20% Low Rolling Resistance Tires Low Drag Brakes Secondary Axle Disconnect Aero Drag Reduction 10%

V6 Abbreviation

LUB EFR CCP DVVL DEAC ICP DCP DVVL CVVL DEAC CCP DVVL CDOHC SGDI TRBDS

16 16 173 278 173 105 210 383 623 173 278 -420

DSL

-

DSL ADSL

1125

EPS IACC MHEV HVIA ISG

60 75 60 -

CVT NAUTO DCT

263 -

PSHEV 2MHEV PHEV

5246 -

MR1 MR2 MR5 MR10 MR20 ROLL LDB SAX AERO

321 96 134

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

J Probabilities in Estimation of Fuel Consumption Beneits and Costs

The com m ittee estim ated cum ulative fuel consum ption m ittee’s estim ated conidence interval for technolog y i and by successively m ultiplying the base fuel consum on ptiby assum e thatσi2 is a reasonable estim ate of the variance of one less the estim ated fractional reductions associ ated with the estim ate, whose distribution is assum ed toym be s m etric. speciic technologies. The estim ates of cum ulative ost c F urtherm ore, it is assum ed that the individualnology tech im pacts are obtained by successively adding individ ual estim ates are independent. The ex act form ula eforvarith retail price eq uivalent change estim ates. The comtteem i ance of the product of n independent random variables was has provided rough conidence intervals for the individual derived by Goodm an ( 1 9 6 2 ) , who also pointed t ifout thetha fractional reductions. The conidence intervals are based sq uare of the coeficients of variation σ( i2/f2) of the variables on the com m ittee’s judgm ent and have not beened deriv in is sm all, then an approx im ation to the ex actce varian should a rigorous, reproducible m ethod. The com m ittee’s tent in in be reasonably accurate. The com m ittee’s estim fates fuelo providing the conidence intervals is to convey its opinion consum ption reduction are on the order of f = 1 . –0 05 , that all such estim ates are subject to uncertainty.The com in general, while its estim ates of the conidence tervals in m ittee believes it is im portant to com m unicate degree the 1 . 6σ 4are on the order of 0 . 0 2 . Thus the sq uare ofo-the c of uncertainty in estim ates of fuel consum ption ential pot eficients of variation are on the order of 0 . 0 0 0 1. 95 0/ 2 5 = and cost even though it cannot m ak e these estim with ates 0 . 0 0 0 1 6 . H owever, Goodm an also notes that x imhis ate appro precision or scientiic rigor. Given the judgm ental nature of form ula tends to underestim ate the variance, ineral. gen A s our fuel consum ption and cost estim ates, the comtee m has it a conseq uence, we use his ex act form ula, shownwbelo in attem pted to aggregate them with an appropriate ree degof Eq uation 2 . m athem atical rigor. The following describes the m ethod used by the com m ittee to aggregate its estim ates ofrtainty unce for n  n σ2    n  individual technologies to estim ate the conidencentervals i Var  ∏ fi  = ∏ fi 2  ∏  i2 + 1 − 1  i =1  i =1    i =1  fi for the full technology pathways shown in Chapter 9. Eq uation 2 A ssum ing the individual estim ates of cost im re pacts a  n  independent, the variance of the sum of n cost estim ates is 1.64 × StdDev ( fn = 1.64 × Var  ∏ fi   i =1  eq ual to the sum of the variances. Thus the standar d deviation of the sum is the sq uare root of the sum of theared sq stanu dard deviations. L et±1 . 6ω 4be the com m ittee’s estim ated Eq uation 1 can be used to calculate a conidence int erval conidence interval for the retail price im pact ofechnology t for either the cum ulative fuel consum ption or cum ativeul i. The conidence interval for the sum of i price im pact escost im pacts by calculating the sq uare root of the variance tim ates would be ± 1 . 6ω,4 whereωn is deined as follows. and m ultiplying by 1 . 6 4 . The com m ittee believes t its tha 1 . 6σi4bounds represent, very approx im ately, a 9 0 percent n conidence interval. A ssum ing that the cost and fuel conω n = ∑ ω i2 Eq uation 1 sum ption estim ates are also independent, the probab ility that i −1 fuel consum ption is within its 9 0 percent conidence bounds L etfi be the im pact of technology i on fuel consum ption, and cost is within its conidence bounds at the sam etim e where fi = 1 ∆–1 and ∆1 is the ex pected fractional reducim plies that the joint conidence interval is an 8 percent 1 tion ex pected from technology I, and let pi be the ex pected conidence interval. increase in retail price eq uivalent. L ±et1 . 6σi4be the com -

)

2 0 8

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 0 9

AP P ENDIX J

)

Prob ( fi − 1.64σ i < fi < fi + 1.64σ i = 0.9

)

Prob ( pi − 1.64σ i < pi < pi + 1.64σ i = 0.9 Prob ( fi − 1.64σ i < fi < fi + 1.64σ i

 Prob ( p − 1.64σ i

i

) )

< pi < pi + 1.64σ i = 0.9 × 0.9 = 0.81

interval to an 8 1 percent conidence interval would be approx im ately 1 . 6 4 / 1 . 3 1 = 1 . 2 5 . Thus, y rough an appropriatel adjustm ent factor to convert the individual coniden ce intervals to a joint conidence interval of 9 0 percent wo uld widen them by about 2 5 percent.

REFERENCE The com m ittee did not address what speciic probabil ity distribution the uncertainty about fuel consum ption and cost im pacts m ight tak e. H owever, if one assum llow es they a fo norm al distribution, then the ratio of a 9 0 percent conidence

Goodm an, L . A . 1 9 6 2 . The variance of a product randomof K variables. J ournal of the A m erican S tatistical A ssociation 2 9 57 7) :5 ( 4 -6 0 .

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

K Model Description and Results for the EEA-ICF Model

METHODOLOGY OVERVIEW

m any of the technology effects on each source of lo ss have been determ ined from data presented at technicalnferco The lum ped param eter approach to fuel consum ption ences. H owever, the EP A does not docum ent how ari-the v m odeling uses the sam e basic principles as all sim lationu ous losses were determ ined for the baseline vehicle : It says m odels, but instead of calculating fuel consum ption second only that the vehicle has a ix ed percentage of fuellost to by second, as is som etim es done, it uses an average cycle. each category. The EP A also does not docum ent how he t S uch an approach has been used widely by industry nd a regutechnology- speciic im provem ents in each category loss of latory agencies, m ost recently by the U . S . Environ m ental were characteriz ed. It appears that the losses forboth the P rotection A gency ( EP A ) to help assess the 2 60 1 2 - 2 0 1 baseline vehicle and the effects of technology im prove proposed fuel econom y standards ( EP A , 2 0 0 8thod ) . The m e m ents were based not on com puted values but on ex rt pe can be generally described as a irst- principles- bas ed energy opinion. balance, which accounts for all the different categories of energy loss, including the following:

MODEL COMPUTATIONS • L osses based on the second law of therm odynam, ics • H eat loss from the com busted gases to the ext and haus coolant, • P um ping loss, • M echanical friction loss, • Transm ission losses, • A ccessory loads, • V ehicle road load tire and aerodynam ic drag loss es, and • V ehicle inertial energy lost to the brak es.

H ere the com m ittee sum m ariz es the EEA - ICF m od GM researchers S ovran and Bohn ( 1 9 8 1 ) used lnum erica integration over the F ederal Test P rocedure city danhighway driving cycles to determ ine the energy req uired at the wheel to m ove a vehicle over the driving cycle as function a of its weight, frontal area, drag coeficient, andire t rolling resistance coeficient. This procedure is used to com pute the energy req uirem ent at the wheel for the givenaseline b vehicle and translated to energy at the engine output shaft by using transm ission and driveline efficiency fact ors ( which differ by transm ission type and num ber of ars) ge Conceptually, each technology im provem ent is charac teriz ed derived from the open literature. A ccessory energy req uireby the percent change to each of the loss categories. If m ulm ents are added as a ix ed energy am ount that unction is a f tiple technologies are em ployed to reduce the samcategory e of engine siz e. This determ ines total engine output energy; of loss, each successive technology has a sm allermi pact as average cycle power is then com puted by distributin g the the category of loss becom es closer to z ero. energy over the cycle tim e when positive engine out put is EEA - ICF 1Inc. has developed a lum ped param eter m odel req uired—that is, the tim e spent at closed throttle brak ing that is broadly sim ilar in scope and content to theEP A and idle are accounted for separately. A verage cycl eR P M m odel ( D uleep, 2 0 0 7 ) . In this m odel, eline all of the bas ex cluding idle was obtained for speciic vehicles from vehicle energy losses are determ ined com putationall y, and sim ulation m odels on speciic vehicles, and these ta da are scaled by the ratio of the N/ V for the data vehicle and the 1 Energy and Environm ental A nalysis, Inc. ( EEA acq ) was uired by baseline vehicle. The data are used to determ ine erage av ICF International during the course of this study.In this appendix , referbrak e m ean effective pressure ( BM EP ) for the ve positi ence is m ade to EEA - ICF , although in the report a whole as reference is power portion of the cycle. m ade sim ply to EEA . 2 10

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

AP P ENDIX K

2 11

F uel consum ption is determ ined by the following m ates, and the EP A concluded the results of their odelm relationship: were plausible, although a few technology pack ages req uired additional investigation. The EP A has indicatedatthit will IM EP = BM EP + F M EP + P M EPcontinue to use the lum ped param eter approach asanalytian cal tool, perhaps adjusting it to im prove its ideli ty as m ore where I is for indicated, F is for friction, P or is pum f ping, sim ulation results becom e available. and M EP is the m ean effective pressure in eachgory. cateThe EEA - ICF also perform ed analysis for the NR C Com m itfuel consum ption m odel is derived from a m ethodolog y to tee on A ssessm ent of Technologies for Im provinght-L ig estim ate an engine m ap using a sem iem piricaldevelm odel D uty V ehicle F uel Econom y ( D uleep, 2 0 0 ased 8 a, 2 0 0 8 b) oped by researchers at F ord and the U niversityNottingham of on the com m ittee’s ex perience, when a num berine, of eng ( S hayler et al. , 1 9 9 9 ) . In this form ulation, onsum fuel ption c is transm ission, and other technology im provem ents simareulproportional to IM EP divided by indicated thermficiency al e taneously added to a baseline vehicle, the net fueleconom y ( som etim es called the W illans line) , friction termis de ined beneit can be approx im ated by tak ing 9 0 percent of the addiem pirically from engine layout and is a functionRofP M only, tive sum of the individual technology beneits, aseveloped d and P M EP is sim ply intak e m anifold pressure heric ( atm osp by EEA - ICF . The com m ittee used this techniqvelop ue toa de pressure) . Intak e m anifold pressure is solved for ny given a q uick approx im ation of the level of agreem ent y between lik el BM EP , since IM EP is also proportional to intak ssure. e pre the R icardo sim ulations and the EEA - ICF lum mpedeter para This m odel ex plicitly derives therm al eficiency, iction fr loss, m odel. It was able to perform a q uick analysis nlyof 2 o3 of and pum ping loss for the baseline vehicle. F uel sum con ption 2 6 pack ages developed by R icardo, since thereno were data at idle and closed throttle brak ing are m odeled functions as on H CCI engines, which were used in three of the cardo R i of engine displacem ent only. The baseline engine always is technology pack ages. m odeled with ix ed valve lift and tim ing, and the m pu ping R icardo included one technology for which the com ttee m i loss is adjusted for the presence of variable valve tim ing if had no speciic data. It called this “fast warm - up” technology applicable. The m odel can be construed as a two- nt poiapbecause it involved the control of coolant low to the engine prox im ation of a com plete engine m ap and is reasona very im m ediately after cold start. Based on the datasented pre able representation of fuel consum ption at light an d m oderate by R icardo, the beneit of the technology was estimtedaat loads where there is no fuel enrichm ent. 1 percent, including the beneit of the electric wat er pum p. The technologies are characteriz ed by their effecton each A ll other technology beneits were based on the datafrom of the losses ex plicitly accounted for in the m odel , and the ICF - EEA previous reports to D OE on fuel economhnoly tec representation is sim ilar in concept to the represe ntation in ogy. These beneit estim ates were adjusted for theresence p the EP A m odel. In the EEA - ICF analysis, the eecom col- m itt or absence of technologies on the baseline vehicle, since lected inform ation on the effect of each engine tec hnology on all beneits in the D OE reports have been typicallydeined peak engine eficiency, pum ping loss, and friction oss las a relative to an engine with ix ed valve tim ing andfoura cycle average from technical papers that describe m easured speed autom atic transm ission. The results are trated illus in changes in these attributes from prototype or produ ction F igure K . 1 , and the plot shows the difference betwe en the system s. W hen these losses are not ex plicitly m red,easu they R icardo results and the q uick approx im ation m ethod. are com puted from other published values such as the change In 1 6 of the 2 3 cases, the R icardo estim ate in +is with 5 perin com pression ratio, the change in torq ue, ormthe easured cent of the q uick estim ate. In two cases, the do R estim icar ates change in fuel consum ption. were m ore than 1 0 percent lower than the q uick m esti ates, as shown in F igure K . 1 . In ive cases, the R icardo m ates esti were 1 0 percent ( or m ore) higher than the q uick .estim The difate Comparison of Results to Detailed Simulation Model ference im plies that the beneits are larger than ethsim ple sum Outputs of individual technology beneits and that technology synerBoth EEA - ICF and EP A have com pared the lum gies pedare positive. The com m ittee also ex am ined technology the param eter results with new full- scale sim ulationdeling m o pack ages in the two “low” and ive “high” outliers.Both low results on several vehicle classes with different com binations outliers had technology pack ages with a continuousl y variable of planned technological im provem ents. The sim ons ulati transm ission ( CV T) as one of the technologies.ive Thehigh were done by the consulting irm R icardo, Inc. , docuand outliers had no m ajor technology im provem ent inmcom on. m ented in a separate report ( R icardo, 2 0 0 8 cardo ) . The R i M ore detailed analysis was also done with the EEACF- I work m odeled ive baseline vehicles ( standard car, argel car, lum ped param eter m odel. Constraints on resources d timan e sm all M P V , large M P V , and large truck ology ) and 2 6 allowed techn the com m ittee to analyz e only 9 of theases 2 3 c com binations, covering gasoline and diesel powerains tr used with the lum ped param eter m odel, but the 9 cases cludedin in the EP A m odel, but there was no sim ulation brids. of hy both high and low outliers from the previous analys is. Three In a m ajority of the com parisons done by EP Aum , the ped l technology pack ages were analyz ed for a standard r, ca param eter m odel estim ates were close to the R estiicardo which used a Toyota Cam ry baseline; three for a com pact

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 12

ASSESSMENT OF F U EL CONOMY E TECH NOLOGIES F OR LIGH T- DU TY V EH ICLES

20

RICARDO-EEA %

15 10 5 0 –5 10

20

30

40

50

–10 –15 –20

EEA QUICK ESTIMATE %

FIGU R E K . 1

Com parison of the difference between R icardo, the Inc. , results and the q uick approx im m ation ethod.

van, which used a Chrysler V oyager baseline; andree th for a standard pick up, which used a F ord F - 1 5line. 0 base Table K . 1 shows the results and com pares them those with of the q uick m ethod. The m ore detailed m odeling uced red the average difference between the R icardo estim sate and the com m ittee estim ates for the Toyota Cam ry andrysler the Ch com pact van but increased the difference for the FrdoF - 1 5 0 truck . The largest observed difference is for P ack ge 1a 0 on the F ord, where the baseline 5 . 4 - L V 8 is yreplaced a 3 . 6 b- L V 6 turbo GD I engine and the downsiz ing is consisten t with the 3 3 percent reduction that was used.

Comparison of Model Results to NRC Estimates The NR C study has developed a series of technology paths whose com bined effect on fuel consum ption was estim ated from ex pert inputs on the m arginal beneits of each successive technology given technologies already adopted. P aths were speciied for ive different vehicles: smll cars, a interm ediate/ large cars, high- perform ance sedans, ody- bonfram e sm all truck s, and large truck s. There were substanno tial differences in the paths or the resulting fuel consum ption estim ates across the ive vehicles: A ll estim ated creases de in fuel consum ption were between 2 7 and 2 9 percent for

TA BL E K . 1 Com parison of F uel Econom y Im inprovem P ercent) entsfrom ( A nalysis, and the EEA - ICF M odel V ehicle

Technology P ack age

Toyota Cam ry

Z

Chrysler V oyager

F ord F - 1 5 0

1 2 R M S difference 4 6 b 1 6 R M S difference 9 1 0 1 6 R M S difference

R icardo Estim ate 3 3 .0 1 3 .0 2 2 .0 2 6 .0 3 5 .5 4 1 .0 3 2 .0 4 2 .0 2 3 .0

R icardo, Inc. , M odeling, EEA uick - ICF Q EEAR Q esult uick 2 3 .7 2 3 .7 2 2 .4 8 .1 5 3 0 .9 3 3 .3 2 8 .5 7 .8 5 3 0 .0 2 8 .2 2 1 .3 8 .1 2

EEA M odel R esult 3 2 .6 2 3 .1 2 1 .9 5 .8 5 2 9 .9 3 5 .5 3 6 .6 3 .3 9 2 8 .3 2 6 .4 2 3 .4 9 .2 5

NOTE: R M S , root m ean sq uare difference between EEA the - ICF estim ate and the R icardo estim ate.erences The diff seem to be in the sam e range as the differences between the EP A estim ates with their m luped param eter m odel and the R icardo estimis ates. also im It portant to note that the EP A m odels result are m ore consistent with the results of the EEA - ICF m odel. The “low” R icardo result for P ack agehe 1 Cam on t ry is also signiicantly lower than the EP A estim ate of 2 0 . 5 percent fuel econom y beneit,is which closer to the EEA - ICF estim ate of 2 3 percent an to the th R icardo 1 3 percent estim ate. S imhe ilarly, t high R icardo estim ate for P ack age 1 0 on the1F5 ord 0 Fis also substantially higher than the EP A ate estim of 3 0 . 5 percent fuel eficiency gain, which inis, turn, higher than the com m ittee estim ate of 2rcent 6 . 4butpe m uch lower than the R icardo estim ate2 ofpercent. 4

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

AP P ENDIX K

2 13

spark - ignition engines and 3 6 and 4 0 percentesel for endi TA BL E K . 2 Com parison of F uel Consum ption R eductions gines. S ince the “perform ance sedan” and interm teedia sedan ( in P ercent) for NR C Estim ates and the EEA - ICF l M ode speciications were not very different, only the sm llacar, one S park Ignition P ath NA S EEA - ICF interm ediate car, and two truck s were sim ulated. m ulation S i S m all car 2 7 2 6 .7 was done for the spark ignition engine and the diesel engine Interm ediate/ large car 2 9 2 7 .3 paths, but not for the hybrid path. BOF sm all truck 2 7 2 7 .3 Table K . 2 lists the m odel results versus the com tee m itBOF large truck 2 9 2 6 .2 estim ates for the eight cases ( four for spark ignit ion and four D iesel path for diesel) . In general, the m odel forecasts areryveclose S m all car 3 7 3 5 .7 to but typically slightly lower than the forecasts of ex perts, Interm ediate/ large car 3 7 3 6 .2 although well within the range of uncertainty included in the BOF sm all truck 3 7 3 6 .6 com m ittee estim ate. Only one vehicle, the fulltruck siz ,e BOF large truck 4 0 3 6 .5 shows a larger difference on the diesel path. H isto rically, NOTE: BOF , body on fram e. the com m ittee’s m ethod of forecasting the m beneit arginal of technology along a speciied path has been criticiz ed as potentially leading to an overestim ation of beneits for spark ignition engines since it could lead to infeasible solutions if total pum ping loss reduction estim ated ex ceededactual the REFERENCES pum ping loss. The sim ulation m odel output’s ex t track pliciD uleep, K . G. 2 0 0 7 . Overview of lum ped param el. P eter resentation m od to ing of the losses addresses this issue directly to ensure that the National R esearch Council Com m ittee for the essm A ssent of Techno basic scientiic relationships are violated. nologies for Im proving L ight- D uty V ehicle F om uel Econ y on October 2 6 , W ashington, D . C. F uel consum ption is decreased by reducing the tract ive D uleep, K . G. 2 0 0 8 a. EEA - ICF A nalysisulation of R icardo outputs.sim energy req uired to m ove the vehicle ( by reducingight, we P resentation to the National R esearch Council Comttee m for i the aerodynam ic drag, or rolling resistance) , reducing losses to A ssessm ent of Technologies for Im proving L ightV Dehicle uty F uel the transm ission and drive line, reducing accessory energy Econom y on F ebruary 2 6 , W ashington, D . C. consum ption, or reducing engine fuel consum ptionring du D uleep, K . G. 2 0 0 8 b. EEA - ICF analysistation update. to the P resen National R esearch Council Com m ittee for the A ssessm chnologies ent of Te for idle and closed throttle brak ing. F uel consum ption can also Im proving L ight- D uty V ehicle F uel Econom 1y on , W A pril ashington, be reduced by increasing engine eficiency over the cycle, D . C. which is accom plished by increasing peak eficiency or by EP A ( U . S . Environm ental P rotection A gency) EP A. 2S0 taff 0 8Technia. reducing m echanical friction and pum ping loss. F resigu K .2 cal R eport: Cost and Effectiveness Estim ates of Tec hnologies U sed through K . 5 show the technology path steps and trac k the to R educe L ight- D uty V ehicle Carbon D iox ide ns.Em EP issio A 4 2 0 R - 0 8 - 0 0 8 . A nn A rbor, M ich. reductions from both approaches separately, withethreducR icardo, Inc. 2 0 0 8 . A S tudy of the P otential ivenessEffect of Carbon tion in energy req uired to drive through the test yccle shown D iox ide R educing V ehicle Technologies. R eport e Environm to th ental on top and the engine eficiency shown below. P eakngine e P rotection A gency. J une 2 6 . eficiency actually decreases slightly due to turbocharging S ovran, G. , and M . Bohn, 1 9 8 1 . F orm ctive ulae energy for the tra req uireand downsiz ing, but the cycle eficiency increases fro m m ents of the vehicles driving the EP A schedules.E PS aper A 8 1 0 1 8 4 . S A E International, W arrendale, P a. about 2 4 to 2 9 percent owing to reduction in pum g and pin . A m ethod brak e friction loss ( blue part of the bar) . The general trends are very S hayler, P . , J . Chick , and D . Eade. 1 9 9 of9 predicting speciic fuel consum ption m aps. S A E P aper 1 95 96 9. S- 0A 1 E- Inter0 5 sim ilar across all four vehicle types, but the k feature ey is national, W arrendale, P a. that pum ping and friction loss are not reduced tohysically p im possible levels for the solution.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 14

ASSESSMENT OF F U EL CONOMY E TECH NOLOGIES F OR LIGH T- DU TY V EH ICLES

0.35 0.33 0.31 0.29

kWH/mile

0.27

ACC DRIVETRAIN TRANSMISSION

0.25

TORQUE CONV. TRACTION

0.23 0.21 0.19 0.17 0.15 BASE COMP.

4-VALVE

GDI/TURBO

ENG FRIC.

CVVL

DCT6

WT. REDUC

RRC REDUC.

ACC

Technology

FRICTION

PUMPING

0.35

ENGINE EFFICIENCY

0.33 0.31

Efficiency Percent

0.29 0.27 0.25 0.23 0.21 0.19 0.17 0.15 BASE COMP.

4-VALVE

GDI/ TURBO

ENG FRIC.

CVVL

DCT6

WT. REDUC

RRC REDUC.

ACC

Technology

FIGU R E KTechnology .2 path steps and reduction in energy req uired to drive through the test cycle ( top) and thengine e eficiency ( bottom ) , body- on- fram e sm all truck .

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

2 15

AP P ENDIX K

0.25 ACC DRIVETRAIN TRANSMISSION TORQ U E CONV. TRACTION

0.24

k W H /m il e

0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 BASE COMP.

LESS ICP

VVL+DCP

ENG FRIC.

GDI/ Turb o

DCT

W T. REDU C

RRC REDU C.

ACC

RRC REDU C.

ACC

Tec h n ol ogy

FRICTION

Ef f ic ien c y Perc en t

0.4

PU MPING

ENGINE EFICIENCY

0.35

0.3

0.25

0.2

0.15 BASE COMP.

LESS ICP

VVL+DCP

ENG FRIC.

GDI/ Turb o

DCT

W T. REDU C

Tec h n ol ogy

FIGU R E KTechnology .3 path steps and reduction in energy req uired to drive through the test cycle ( top) and thengine e eficiency ( bottom ) , m idsiz e sedan.

2 16

ASSESSMENT OF F U EL CONOMY E TECH NOLOGIES F OR LIGH T- DU TY V EH ICLES

ACC DRIVETRAIN TRANSMISSION TORQUE CONV. TRACTION

0.22

0.2

kWH/mile

0.18

0.16

0.14

0.12

0.1 BASE COMP.

VVL+DCP

GDI/ Turbo

ENG FRIC.

VVLT

DCT

WT. REDUC

RRC REDUC.

ACC

RRC REDUC.

ACC

Technology FRICTION

0.4

PUMPING

ENGINE EFFICIENCY

Efficiency Percent

0.35

0.3

0.25

0.2

0.15

0.1 BASE COMP.

VVL+DCP

GDI/ Turbo

ENG FRIC.

VVLT

DCT

WT. REDUC

Technology

FIGU R E KTechnology .4 path steps and reduction in energy req uired to drive through the test cycle ( top) and thengine e eficiency ( bottom ) , sm all car.

2 17

AP P ENDIX K

ACC DRIVETRAIN TRANSMISSION TORQUE CONV. TRACTION

0.45

0.4

kWH/mile

0.35

0.3

0.25

0.2

0.15 BASE COMP.

4V

GDITURBO

ENG FRIC.+OIL

VVLT

DCT6

wt. REDUC

REDUC.

ACC

Technology

FRICTION

0.4

PUMPING

ENGINE EFFICIENCY

Ef fciency i Percent

0.35

0.3

0.25

0.2

0.15 BASE COMP.

4V

GDITU RB O

ENG FRIC.+OIL

VVL T

D CT6

w. t REDUC

REDUC.

ACC

Tech nolo gy

FIGU R E KTechnology .5 path steps and reduction in energy req uired to drive through the test cycle ( top) and thengine e eficiency ( bottom ) , full- siz e truck .