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# OAR Box 1846 Prepped byOllie Stewart



### Document

Number: 

# 9 ) II-B— 6 Docket Number: 

# A-90-0 7

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UNITE D STATE S ENVIRONMENTA LPROTECTIO N AGENC Y AN N ARBOR . MICHIGA N 4810 5 

### HAR2 -} 1 3

MEMORANDU

M
SUBJECT : FROM : TO : THRU : OFFIC E O F AI R AN D RADIATIO N

Vehicl e Selectio nProcedure s fo r th e Propose d Fuel s an d Fue l Additive s Rulemaking Jame s Greaves , Mechanica l Enginee r Standard s Developmen t an d Suppor t Branc h Docke t No . A-90-0 7 Judit hGray , Projec t Manage r Standard s Developmen t an d Su p 

## 4&*b(?r&^-~

Glenn W . Passavant , Senio r Projec t Manag e Standard s Developmen t an d Suppor t Branc h Cheste r J . France , Chie f Standard s Developmen t an 

## 3U^^^M^M M

ppor t Branc h Summary Thi s memorandu

m illustrate s ho wth e vehicl e selectio n procedur e describe d i n th e Fuel s an d Fue l Additive s ProgramNotic e o f Propose d Rulemaking (NPRM ) woul d b e performe d fo r gasolin e an d diese l fuels . Th e result s ar e vali d onl yfo r th e selectio no f 199 1 mode l yea r gasolin e an d diese l fuele d vehicles/engines , bu t th e selectio n metho d i s applicabl e t o othe r mode l year s an d fue l families . Background A s par t o f th e propose d Fuel s an d Fue l Additive s Registratio n programimplementing Sectio n211(b)(2 ) o f th e Clea nAi r Act , emission s fro

mmoto r vehicl e fuel s an d fue l additive s woul d b e generate d and teste d t o determin e thei r compositio nan d potentia l effect s o n huma n health . Th e fue l an d additiv e manufacturer s woul d b e responsibl e fo r selecting an d acquiring ne wvehicles/engine s t o generat e thes e emission s according t o criteri a specifie d i n th e NPRM . Th e proposa l require s th e us e o f ne wvehicle s t o ensur e tha t emission s ar e attributabl e t o th e tes t fue l o r additive/fue l mixture . Th e criteri a tha t determin e th e vehicle/engin e model s eligibl e fo r us e i n th e programar e describe d i nSectio nV(A ) (1 ) o f th e NPRMpreambl e an d Sectio n79.47(a ) o f th e propose d regulations . Th e proposa l specifie s tha t vehicl e selectio nwoul d b e performe d b y th e fue l and additiv e manufacturer s fo r th e yea r i n whic hthei rP. 3

testin g i s initiated . The curren t proposa l require s th e us e o f emission s fromonl yon e vehicle/engine ; however , EP Ai s considering an increas e i n th e numbe r o f require d vehicles/engine s t o improv e th e accurac yo f th e program . Vehicle/engin e selectio nstart s wit hdetermining th e vehicle/engin e clas s an d subclas s whic hconsume th e greates t amoun t o f fue l i n th e fue l famil yo f interest . Next , a surveyo f th e engin e familie s withi n th e identifie d clas s an d subclas s fromth e previou s mode l yea r i s performe d an d th e mos t commo nemissio n contro l technologyequipmen t an d characteristic s ar e determined . Th e five highes t selling engin e familie s wit hthes e characteristic s ar e the n identified . Representative s fromthes e engin e familie s o f th e curren t mode l yea r ar e selecte d a s th e vehicles/engine s eligibl e t o generat e emission s fo r th e program . Adiagram o f thi s proces s i s show

n i n Figur e 1 an

d th e step s ar e describe d i ndetai l i n thi s memorandum . Selectio n o f Vehicle/Engin e Model s fo r Gasolin e and Diese l Testing Vehicle/engin e clas s refer s t o th e broades t classificatio no f vehicles/engine s use d i nth e certificatio no f ne wvehicle s (4 0 CF R 86 ) . A t th e presen t time ther e ar e four on-road vehicle/engin e classes : light-dut yvehicle s (LDV) , light-dut ytruck s (LDT) , heavy

dut yengine s (HDE) , and motorcycles . However , th e engines , emissio n contro l systems , and , therefore , emission s fro mgasolin e LD V an d LDT ar e verysimilar . Th e LD V an d LD T classe s ar e thu s propose d t o b e combine d fo r th e purpos e o f thi s program . Th e propose d vehicle/engin e selectio n metho d require s tha t th e vehicle/engin e clas s tha t reflect s th e highes t yearl yconsumptio n o f fue l i n th e fue l famil yo f interes t b e use d t o tes t member s o f th e fue l family . Thus , th e gasolin e fue l famil ywoul d b e represente d b

yth e combine d LD

V an d LDT classe s an

d th e diese l fue l famil ywoul d b e represente d byth e HD E class . Th e nex t selectio n criterio n i s th e vehicle/engin e subclass . Subclas s refer s t o division s withi na vehicle/engin e clas s base d typicall yo n vehicle/engin e size . Subclas s i s als o know na s "primar yintende d servic e class " fo r HDE . A s wit hvehicle/engin e class , subclas s i s chose nt o represen t th e greates t consumptio no f fue l withi n th e fue l famil yo f interest . No t al l vehicle/engin e classe s contai n subclasses , an d th e subclas s selectio n proces s i s no t applicabl e i n thes e cases . Th e LD V clas s doe s no t hav e subclasses ; however , th e LDT clas s i s currentl ydivide d int o truck s abov e an

d belo w375 0 pound s loade d vehicl e weight , and starting i n 1994 , a tota l o f four LD T subclasse s wil l b e specified . If , a s proposed , th e LD

V an d LDT ar e combine d fo r th e purpose s o f thi s rulemaking , th e LD T subclas s distinction s woul d no t b e made , an d LDV/LD T woul d b e treate d a s on e clas s wit hn o subclasses . Th e HD E clas s contain s thre e subclasses--light , medium , an d heavy . Th e HD E subclas s tha t represent s th e greates t annua l diese l fue l consumptio n i s th e heav ysubclas s (HHDE) . Onc e th e vehicle/engin e clas s an d subclas s hav e bee nP. 4

determined , a surveyi s performe d t o determin e th e mos t commo n emissio n contro l technologycharacteristic s withi n th e identifie d clas s an

d subclass . Th e surveyprocedur e make s us e o f standar d manufacture r an

d engin e classification s calle d "engin e families, " whic hhav e previousl ybee ndefine d fo r th e purpose s o f vehicl e certificatio n (4 0 CF R86.082- 2 an d 86.090-24) . First , th e engin e familie s whic hpertai n t o th e selecte d clas s and subclas s ar e listed . Next , th e pertinen t engin e familie s ar e sorte d int o large r group s according t o similaritie s i nthei r emissio ncontro l technologycharacteristics 1

. Finally , vehicle/engin e sale s ar e summe d acros s th e engin e familie s i neac htechnologygrou p t o determin e th e mos t commo nengin e an d emissio ncontro l characteristics . Th e grouping o f engin e familie s i s t o b e base d o nthos e technologysystem s which , according t o goo d engineering judgment , ar e likel yt o hav e th e greates t impac t o nemissions . Thus , they mayno t b e a s design specifi c a s ar e some o f th e criteri a use d t o divid e familie s int o engine/emissio ncontro l systemcombinations . Onc e thes e system s hav e bee n selected , th e option s fo r eac hsystem ar e identified . Fo r example , th e option s fo r catalyti c converte r system s coul d b e 3-way , 3-wa yplu s oxidation , oxidation , and n o catalyti c converter . Th e option s fo r some variables , suc ha s th e existenc e o f an exhaus t ga s recirculatio n valve , coul d b e ye s o r no . Th e engin e famil ysale s applicabl e t o eac hoptio nar e summe d separatel yt o determin e th e systemoptio nwit hth e greates t sales . Thi s procedur e i s repeate d fo r th e remaining vehicle/engin e system s identifie d a s mos t affecting emission s s o tha t a lis t o f th e mos t commo n emissio n contro l characteristic s i s determined . Survey s fo r 199 0 mode l yea r LDV/LD T an d HHD E engin e familie s hav e bee n performe d an d th e result s ar e presente d i nTable s 1 an d 2 . Th e light-dut ygasoline-fuele d vehicle/engin e system s identifie d b

yEP Aa s mos t affecting emission s are : fue l system type , catalys t type , exhaus t ga s recirculatio nvalve , ai r injection , feedback , and adaptiv e learning . Th e diesel-fuele d HHD E system s identifie d b yEP Aare : fue l injectio ncontro l type , aspiratio n type , and fue l injectio n position . A s show ni n Tabl e 1 , th e mos t commo n technologycharacteristic s fo r light-dut yvehicle s are : multipor t fue l injection , a 3-wa ycatalys t wit hn o oxidation , close d loop feedbac k (include s anoxyge nsensor) , n o ai r injection , an exhaus t ga s recirculatio nvalve , an d adaptiv e learning . Tabl e *I n some instance s ther e ar e emissio ncontro l system difference s withi n an engin e famil ywhic hcaus e engin e familie s t o b e furthe r divide d int o engine/emissio n contro l system combinations , als o know n a s engine/systemcombination s (4 0 CF R 86.082- 2 and OM S AdvisoryCircular s 20 B an d 20B-1) . Th e sorting proces s describe d abov e migh t requir e th e engine/system combination s withi n an engin e famil yt o b e sorte d int o differen t technologygroups . I n general , fewengin e familie s hav e mor e tha n on e engine/systemcombination , an d eve nfewe r woul d b e divide d int o mor e tha n on e technologygroup .P. 5

2 show s tha t th e mos t commo n technologycharacteristic s fo r th e HHD E are : turbocharge r wit hair-to-ai r aftercooling , mechanica l contro l o f fue l injection , an d direc t injectio no f fue l int o th e combustio n cylinders . Onc e th e se t o f engin e familie s containing th e mos t commo n emissio n contro l technologycharacteristic s ha s bee n determined , th e five engin e familie s wit hth e highes t sale s ar e identified 2

. Sinc e dat a concerning curren t mode l yea r engin e familie s coul d b e incomplet e an

d difficul t t o obtain , th e surveyi s t o b e performe d ove r th e engin e familie s fromth e previou s mode l year . However , th e propose d Fuel s an d Fue l Additive s Registratio n program currentl ycall s fo r th e acquisitio no f ne wvehicles/engine s t o generat e emissions . Therefore , engin e familie s fro mth e curren t mode l yea r corresponding t o th e engin e familie s selecte d fro mth e surveyo f th e previou s mode l yea r mus t b e determine d an d acquired . Thi s determinatio n i s base d o n engin e an d emissio n contro l equipmen t similaritie s betwee n familie s i n th e tw o mode l years . A significan t indicato r o f correspondenc e woul d b e i f dat a wer e "carrie d over " from th e previou s mode l yea r engin e famil yfo r curren t mode l yea r engin e famil ycertification . Finally , onc e th e corresponding engin e familie s fromth e curren t mode l yea r hav e bee nidentified , a representativ e mus t b e selecte d fromeac hengin e family . Th e metho d t o b e use d i nthi s programfo r selecting th e appropriat e engin e famil yrepresentativ e i s th e same a s tha t require d fo r vehicl e certificatio npurposes . Generatio n o f emission s fo r th e certificatio n o f light-dut y vehicle s require s a n engin e operating withi n a vehicle . Th e chose n vehicl e configuratio n ( a uniqu e combinatio no f engin e an d vehicl e parameters ) i s th e on e expecte d t o produc e th e larges t tota l mas s o f regulate d emission s fro mtha t engin e family . Fo r heavy-dut y engines , emission s ar e generate d using th e engin e o n a tes t stan d an d a vehicl e i s no t required . Thus , th e engin e cod e ( a uniqu e combinatio n o f engin e parameters ) whic hi s expecte d t o produc e th e larges t mas s o f th e regulate d emission s fromtha t famil yi s selecte d t o represen t th e heavy-dut yengin e famil yfo r th e purpos e o f collecting certificatio n emissio n data . Th e requirement s fo r choosing th e vehicle/engin e t o represen t anengin e famil yinclud e highes t road-loa d power , larges t engin e displacement , maximu mfue l flowcalibration , heavies t equivalen t tes t weight , an d th e transmissio n wit hth e highes t numerica l fina l gea r rati o (4 0 CF R 86 . 090-2 4 (b ) (1 ) (i) , (b ) (1 ) (iv ) , an d (b ) (3 ) (ii)) 3

.

2 Again , th e existenc e o f engine/systemcombination s migh t complicat e th e process . I f th e engine/systemcombination s withi n an engin e famil yar e i n differen t technologygroups , onl yth e sale s o f th e identifie d engine/systemcombinatio nar e use d t o determin e i f i t i s on e o f th e to p five sellers .

3 Th e representativ e froma selecte d engin e famil ywoul d hav e t o b e from

an engine/systemcombinatio n tha t containe d th e mos t commo n emissio n contro l technology .P. 6

Th e representative s o f th e fiv e selecte d engin e familie s woul d b e eligibl e t o generat e emission s fo r th e Fuel s and Fue l Additive s program . I f an

yo f th e engin e familie s selecte d b yth e surveyd o no t hav e a corresponding curren t mode l yea r engin e family , th e selectio n woul d b e limite d t o th e remaining engin e families . I f fewe r tha n five engin e familie s wer e availabl e fo r th e survey(as mayoccu r fo r alternativ e fuels ) th e representativ e o f an y availabl e engin e famil ycoul d b e use d fo r testing . Alternat e Vehicl e Selectio nScenari o i n th e Fuel s an d Fue l Additive s Proposa l I n th e preambl e o f th e propose d Fuel s an d Fue l Additive s Registratio n programNPRM , an alternativ e i s presente d i nwhic h emission s woul d b e generate d from si xvehicle s t o tes t a produc t instea d o f onl yone . Th e greate r numbe r o f vehicle s woul d increas e th e confidenc e tha t coul d b e place d o nth e result s o f th e testing b yprovidin g a greate r amoun t o f emission s tes t dat a a s wel l a s dat a representing a variet yo f vehicle s commo nt o th e o f U.S . fleet . Th e metho d use d t o selec t th e si xvehicle s woul d b e simila r t o th e selectio n metho d describe d above , wit hth e exceptio ntha t th e surveywoul d identif yth e si xmos t commo ntechnologygroup s withi n th e appropriat e vehicle/engin e clas s and subclass . Thes e group s woul d represen t a rang e o f technologycharacteristic s and , therefore , possibl ya broade r rang e o f emission s an d emissio n species . Arepresentativ e fromth e engin e famil ywit hth e highes t sale s withi n eac ho f th e si xgroup s woul d b e use d t o generat e emission s fo r th e program(presumabl yth e highes t emitting configuration) . Th e si xmos t commo n technologygroup s fo r gasolin e and diese l fuel s ar e show ni nTable s 3 an

d 4 fo r vehicl e selectio n fo r th e yea r 1991 . Th e si xgroup s represen t approximatel y9 4 an d 10 0 percent , respectively , o f gasoline-fuele d LDV/LD T an d diesel

fuele d HD E sale s withi n th e appropriat e vehicle/engin e clas s an d subclass . A s a possibl e variation , mor e tha n on e representativ e coul d b e selecte d fro mth e technologygrou p wit hth e highes t sales , i n orde r t o mor e accuratel yrepresen t in-us e emissions . Discussio n EP Awoul d appreciat e comment s o nth e vehicl e selectio nmetho d describe d i n thi s memorandum . Comment s ar e particularl ywelcom e on th e topic s presente d i n thi s section . EP Ausuall ydesign s regulatoryprogram s s o tha t thei r implementatio n doe s no t requir e regula r periodi c inpu t fro mth e EPA . I n thi s spirit , th e propose d Fuel s an d Fue l Additive s program woul d requir e fue l an d additiv e producer s t o determin e th e eligibl e vehicle/engin e model s fo r emissio ngeneratio n testing . However , i t migh t b e mor e efficien t fo r EP At o playa large r par t i n vehicl e selectio n tha n ha s bee n proposed . Muc heffor t an d potentiall y costl yerror s o n th e par t o f th e producer s coul d b e avoide d i f EP A woul d yearl ypresen t a lis t o f th e eligibl e vehicles/engines . Dat a necessaryfo r th e engin e famil ysurveyproces s migh t b e difficul t fo r fue l and additiv e producer s t o obtain . Also , bot hth eP. 7

producer s an EP Awoul d b e mor e assure d tha t testing woul d b e performe d on eligibl e engines/vehicle s i f EP Awer e t o lis t th e eligibl e models . Acompromis e coul d b e adopte d i nwhic hEP Awoul d presen t a lis t o f eligibl e vehicles/engine s during th e firs t few year s o f th e programonly , whe nmuc htesting woul d b e performed , an d responsibilit yshifte d t o th e producer s i nfutur e years . Anothe r optio n woul d b e fo r EP At o determin e eligibl e vehicle s upo n specifi c reques t fro mth e producers . Comment s concerning thi s topi c woul d b e appreciated . Th e nex t discussio ntopi c concern s th e numbe r o f vehicle/engin e model s eligibl e t o generat e emission s fo r thi s program . Allowin g five differen t model s t o b e eligibl e fo r testing i n eac hfue l famil yprovide s flexibilit yduring vehicle/engin e selectio n and acquisition . However , th e potentia l fo r substantia l emissio n variatio n betwee neligibl e model s migh t reduc e th e usefulnes s an

d comparabilit yo f tes t results . I f onl yon e vehicle/engin e mode l wer e eligibl e t o generat e emission s pe r fue l family , th e vehicle/engin e selectio n proces s woul d b e simplified , reducing th e chance s tha t anineligibl e mode l woul d b e chosen . Thi s metho d woul d als o increas e th e opportunit yfo r existing bas e fue l dat a t o b e compare d wit hadditive/bas e fue l mixtur e dat a t o determin e th e emission s attributabl e t o th e fue l additive . Commen t i s requeste d o n th e numbe r o f vehicle/engin e model s pe r fue l famil y tha t shoul d b e eligibl e t o generat e emission s fo r thi s program . Th e fina l issu e t o b e raise d fo r commen t i s whethe r th e mode l yea r surveye d t o determin e th e mos t commo nemissio ncontro l technologyshoul d b e altere d t o allo wtim e fo r engine/vehicl e sale s dat a t o becom e available . Th e proposa l state s tha t engin e familie s b e surveye d fro

m th e mode l yea r previou s t o tha t i n whic htestin g i s initiated . Thus , i f testing wer e t o begi n i n 1994 , 199 3 mode l yea r engin e familie s woul d b e surveyed . However , 199 3 mode l yea r engines/vehicle s ca n b e produce d unti l Decembe r 31 , 1993 . Thus , 199 3 sale s dat a migh t no t becom e availabl e unti l some time i n 1994 . T o solv e thi s problem , a cutof f dat e coul d b e specified . Survey s performe d befor e th e cutof f dat e woul d us e engin e famil ydat a o f tw o mode l year s previous , an d survey s performe d afte r woul d us e engin e famil ydat a o f on e mode l yea r previous . Fo r example , i f th e cutof f dat e wer e Apri l 1 an d th e surveywer e performe d befor e Apri l 1 , 1994 , the n 199 2 mode l yea r engin e familie s woul d b e surveyed . I f th e surveywer e performe d afte r Apri l 1 , 1994 , the n 199 3 mode l yea r engin e familie s woul d b e surveyed . Commen t i s requeste d on whethe r t o adop t thi s metho d and , i f so , wha t th e cutof f dat e shoul d be . Also , wha t mode l yea r engines/vehicle s shoul d b e acquire d fo r testin g whe n th e surveyi s performe d o nengin e familie s o f tw o mode l year s previous ?P. 8



### Figur e 1 : Outlin e o f the Vehicl e SelectionMetho d 1 . Selec t vehicl e clas s an d subclas s wit hth e highes t consumptio n o f fue l withi n th e fue l family . 2 . Specif yth e importan t technologyparameter s affecting emission s fo r th e class/subclas s (e.g. , fue l systemtype , catalyti c converte r type , etc. ) and specif yth e possibl e option s fo r eac h parameter . 3 . Find sale s dat a fo r eac hengin e famil ywithi nth e vehicl e class/subclas s fo r th e previou s mode l year . 4 . Find dat a concerning th e importan t technologyparameter s affecting emission s fo r eac hengin e famil ywithi nth e vehicl e class/subclas s fo r th e previou s mode l year . 5 . Appl yth e engin e famil ysale s dat a i n# 3 t o th e paramete r dat a i n # 4 t o determin e th e sale s fractio nfo r eac hvariabl e i n# 2 (e.g. , i f engin e famil yAaccounte d fo r 40 % o f sales , the nth e catalys t typ e use d i n engin e famil yAwoul d hav e 40 % o f sales . Su m thes e ove r al l pertinen t engin e familie s fo r eac hparameter. ) 6 . Determin e th e previou s mode l yea r engin e familie s whic hhav e al l o f th e mos t frequentl yuse d technologyparameter s (as determine d i n #5) . 7 . O f th e engin e familie s determine d i n#6 , selec t th e five engin e familie s wit hth e highes t sales . 8 . Determin e th e curren t mode l yea r engin e familie s tha t correspond t o th e engin e familie s selecte d i n #7 . 9 . Fo r th e familie s determine d i n#8 , find th e vehicl e configuration s o r engin e code s use d fo r certificatio npurpose s (vehicl e configuration s ar e use d fo r light-dut yvehicle s an d engin e code s ar e use d fo r heavy-dut yengines) . 10 . Th e vehicles/engine s foun d i n# 9 can b e use d fo r th e Fuel s an d Fue l Additive s Registratio nprogram .P. 9



### Tabl e1 : Projecte d199 0Vehicl ean dEmissio nContro l Syste mTechnolog yDistribution s : Light-Dut yGasolin e

Fuele dVehicle s an dTrucks * Syste mo r

Component
Fue lSyste m Catalys t

Feedbac k

Syste m Ai r Injectio n Exhaus t Ga s Recirculatio n Valv e Adaptiv eLearnin g Option s

Mult i Por t Throttl e Bod

y Carbureto r 3-wa y 3-way+Oxidatio n Oxidatio n Non e Close d Loo p Ope nLoop Absen t Presen t Presen t Absen t Presen t Absen t Sale s

Fractio n (% ) 71. 2 26. 9 2. 0 85. 4 14. 3 0. 2 0.0 6 99. 6 0. 4 75. 4 24. 6 77. 3 22. 7 9 8 2



### * Thi s dat aha s bee ntake nfro mTabl eV. 4 o f th epreambl eo f

th e Reformulate dGasolin eProgra mNotic eo f Propose dRulemakin g (5 6 F R 31176 , Jul y9 , 1991,)
. Thes efigure s reflec t bot hlight-dut y vehicl ean dlight-dut ytruc k sales
.P.1 0



### Tabl e 2 : Projecte d 199 0 Vehicl e an d Emissio nContro l SystemTechnolog

yDistribution s : Heav yHeavy-Dut y Diese l Fuele d Engines *

Syste mo r Componen t Option s Sale s Fractio n 

## il l

Aspiratio n T C w/Air-Wate r Aftercoole r 5 7 T C w/Air-Ai r Aftercoole r 4 3 Natura l 0 Turbo-charge d 0 Fue l Syste m

Contro l Mechanica l

Electroni c 7 3 2 7 Fue l Injecto r Positio n Direc t Prechambe r 99 , 0 ,

Not e : T C = turbocharge d

* Thes e figure s hav e bee n calculate d fro mth e 199 0 heavy-dut y diese l engin e certificatio n dat a bas e an d fro mengin e certificatio n applications .

### Tabl e3 : Th eSi xMos t Commo nTechnolog yGroup s Base d o nProjecte dSale s - Light-Dut yGasolin eFuele d Vehicles * p. n

Grou p
1 2 3 4 5 6 Fue l

Syste m Mult i Mult i TB I Mult i Mult i TB I Catalys t

Ai r

Feedbac k

EG R Iniectio n Sale s

3-Wa yAbsen t 3-Wa yAbsen t 3-Wa yAbsen t 3-Way+0 xPresen t 3-Wa yPresen t 3-Wa yPresen t C l

C l C l C l C l C l Loo p Loop Loo p Loo p Loo p Loo p Valv e Fractio n Presen t Absen t Presen t Presen t Presen t Presen t (% )

32. 0 20. 8 20. 7 10. 4 7. 6 2. 3 93. 8 Not e : EGR= Exhaus t Ga s Recirculatio n Mult i = Multipor t Fue l Injectio n TB I = Throttl e Bod

yFue l Injectio n C l Loop = Close d Loop
* Thi s dat a ha s bee n take nfrom Tabl e V. 4 o f th e preambl e o f th e Reformulate d Gasolin e ProgramNotic e o f Propose d Rulemakin g (5 6 F R 31176 , Jul y9 , 1991,) . Thes e figure s reflec t bot hlight-dut y vehicl e an

d light-dut ytruc k sales . XP.1 2



### Tabl e 4 : Th e Si xMos t Commo n TechnologyGroup s Base d o n Projecte d Sale s - Heavy , Heavy-Dut yDiese l Fuele d Engines *

Grou p

1 2 3 4 5 6 Aspiratio n

TA W TA A TA A TA W TA A TA W Fue l Svstem

Contro l Mechanica l Mechanica l Electrica l Electrica l Electrica l Mechanica l Fue l Iniecto r

Positio n Direc t Direc t Direc t Direc t Prechambe r Prechambe r Sale s

Fractio n 

### 1% 1 37. 6 35. 0 21. 5 5. 0 0. 6 0. 2 99. 9 Not e : TA

W= Turbocharge d wit hAir-to-Wate r Aftercoole r TA A= Turbocharge d wit hAir-to-Ai r Aftercoole r
* Thes e figure s hav e bee n calculate d fromth e 199 0 heavy-dut y diese l engin e certificatio n dat a bas e and fromengin e certificatio n applications .