p. 1



# OAR Box 

# 1846 Prepped by Ollie Stewart



### Document

Number: 

# 86 ) IV-A- 8 Docket Number: 

# A-90-0 7

Printed 11/18/20087:30:17

AM Sheet 86 of 93P. 2

MB-M:-fcfc»^ - ifflT M

u V ' 

# Auto/Oil AIR QUALITY 

# •BH B

TECHNICA L BULLETI N

No. 1 INITIA L MAS S EXHAUS T EMISSION S RESULT

S FRO M REFORMULATE D GASOLINE S DECEMBE R 199 0 r}-%-07- 

# JVteb i EJ_LLI_L|J D !



# (conoco )
A DuPon t Subsidiary 

# u

«»• « O f EICEiUHC f



### ^CHRYSU R CORPORATIO N



# Shel l
ARC O <

>

-= r Pttrotdw * orodgc n o l V Atlanti c fltenhatd Comow y



### TIXAC O 

# Ashland.

SUNOC OP. 3



### AUTO/OI L AI R QUALIT

YIMPROVEMENTRESEARCH PROGRA M TECHNICA L BULLETI N No . t INITIAL MAS

S EXHAUS

TEMISSION S RESULT

S FRO M REFORMULATE D GASOUNES

ABSTRAC

T Initia l analyse s o

fmass exhaus

t emissio n results fro m Phase I o fth e Auto/Oi l Ai r Qualit yImprovemen t Researc h Progra m ar e presented

. Fuel s wit h varyin g composition s wer e teste d i n two fleets of vehicles : curren t (1989) an d olde r(1983-1985) models

. Subjec t t o th e caution s an d qualification s describe d i n th e bod yo fthi s bulletin , mass exhaus

t emission s of bot h curren t an d olde rvehicl e fleets wer e affecte d b

y change s i n fue l composition

. Responses t o change s i n olefi n an d MTB E conten t wer e simila rfo rbot h fleets whil e response s t o change s i n aromatics an d Tgj , level s wer e different , an d i n certai n case s opposit e i n th e two fleets. Th e largest percentag e effec t i n th e curren t fleet, th e apparen t impac t o flowe rTg-, o n reducin g exhaus t H C emissions , was not foun d i n th e olde rfleet. Mor e studie s ar

e neede d t o confir m thi s effect

. INTRODUCTIO N Th e Auto/Oi l Ai rQualit

yImprovemen t Research Progra m (AQIRP ) i s a cooperative researc h progra m initiate d bythre e domesti caut o companie s an d fourtee n petroleu m companies

. It

s objective i s t o conduc

t a researc h an d testin g progra m t o develo p data o n th e potentia l improvements i n vehicl e emission s an d ai rqualit y- primaril yozon e - fro m reformulate d gasoline , variou s othe ralternativ e fuels , an d developments i n automotive technology

. Th e AQIR P wil l als o develo p dat a o n th e relativ e cost effectivenes s o

f variou s fuel/vehicl e combinations

. Specifically , Phase I examine s emission s fro m curren t an d olde rvehicle s usin g reformulate d gasoline s whos e composition s var ybetwee n widel yspace d values o f aromati ccontent , olefi n content , oxygenate conten t an d type , sulfu rcontent , RVP , an d 9 0 percen t distillatio n temperature
. Phase I wil l als o examin e emission s fro m Flexibl e an d Variabl e Fue l vehicle s usin g methanol/gasolin e mixtures

. Phase I i s designe d t o hel p identif

yfue l characteristics that meri t furthe rstud yi n future phase s o f th e Program

. Initia l exhaust emission s results fro m th e reformulate d gasoline s teste d i n Phas e I ar e presente d i n thi s Technica l Bulletin

. I t i s envisione d that a numbe ro fTechnica l Bulletin s wil l b e issue d durin g th e cours e o fth e Progra m tha

t wil l addres s additiona l results an d test s o n othe rreformulate d gasolines , methanol/gasolin e mixtures , an d othe r fuels

. Futur

e bulletin s wil l als o contai n results o f ai rqualit

ymodelin g studies

. Attachmen t I show

s th e element

s o f Phase I o

fth e Progra m an d publications

. Aforma l repor t wil l b e issue d upo n completio n o f al l Phase I testing

. 1P. 4



### Th e AQIR P i s i n th e forefron t o f researc h o n ai rqualit

yimprovemen t an d expects t o mak e possibl e a substantia l advancemen t i n th e understandin g o f th e effects o

f fuel s o n vehicl e emissions

. Th e Progra m i s wid e rangin g i n its scop e an d wil l provid e a vas t librar yo f complexdata

. Because muc h o fth e analysi s o

fth e Progra m data ha

s yet t o b e complete d an d continuin g researc h i s expecte d t o lead t o additiona l findings , th e results presente d i n thi s bulleti n mus t b e deeme d qualifie d an d shoul d b e interprete d wit h car e fo rth e reason s give n below

. Althoug h th e fue l blend s teste d wer e formulate d fro m commerciall yavailabl e refiner ystreams , th e compositio n o fsom e blend s i s not necessaril yrepresentative o f fuel s that ar

e o rcoul d b e produced

. Th e "industr yaverage " gasolin e ma ynot b e representative offuel s actuall ysol d i n al l areas an d ma ydiffe rfro m nationa l an d regiona l fuel s i n its specifi ccomposition

. Fue l factor s othe rtha n th e fou rdescribe d i n thi s bulleti n coul d hav

e othe rsignifican t effects o n exhaus t emissions

. Becaus e onl y two level s o

feac h fue l variabl e wer e tested , onl ylinea rinterpolatio n i s possible , althoug h non-linea rrelationship s ma yexis t fo rsom e variables

. Result s ar e reporte d fo r exhaus t emission s only ; evaporativ e emission s ma

yb e a substantia l fractio n o fth e tota l hydrocarbo n emission s an d theywil l b e reporte d i n future bulletins

. N o data hav e bee n obtaine d o n th e possibl e long-ter m effects o f changin g fue l properties

. TES TDESIG N Th e effects o

ffou rgasolin e compositio n parameter s wer e teste d i n two fleets : on e compose d o

ftwent y1989 mode l yea rvehicle s ("curren t fleet'), an d on e compose d o ffourtee n 1983-1985 mode l yea rvehicle s ("olde rfleet'). Factor s that wer

e applie d i n choosin g curren t fleet model s include d hig h productio n volum e an d new/lo wemission s contro l technology

. Curren t fleet vehicle s ha d a minimu m o f10,000 miles o n th e odometer

. Model s i n th e olde rfleet wer e chose n o n th e basi s o fhig h productio n volume s an d th e vehicle s i n th e fleet ha d 40,000-80,000 miles o n th e odometer

. Vehicle s wer

e i n reasonabl e mechanica l conditio n (driveable , safe t o operate , an d wit h al l emission s hardwar

e intact ; repair

s wer e mad e a

s necessary

) an d had emission s level s that wer

e simila rt o thos e i n EPA' s in-us e vehicl e fleet dat a base

. Detail s of th e fleets ar e show n i n Attachments I I an d III

. Fou rfue l sets wil l b e evaluate d i n Phase I as show n below : Fue l Se t Variable s A : Compositiona l Aromatics , MTBE , Olefins , Tg- , B : RVP/Oxygenates RVP , Ethanol , ETBE , MTB E C : Methano l Methanol/Gasolin e Mixtures D : Sulfu rSulfu r Partia l results fro m Fue l Se t Aar e reporte d i n thi s Technica l Bulletin

. Thi s fue l set consiste d of sixtee n fuel s blende d t o represen t a ful l factoria l experimen t involvin g fou rvariable s a

t eac h o f tw o levels

. I n addition , a fue l representin g industr yaverag e level s o f aromatics , olefins , an d Tg-, (withou t MTBE ) wa s tested , a

s wel l as a n emission sP. 5



### certificatio n test fue l a

s a reference

. Th e targe t level s fo reac h fue l variabl e ar e show n below

. Factoria l Desig n Industr y Lo wHiG h Averaa e Aromatics , vo l % 2 0 4 5 32 MTBE , vo l % 0 1 5 0 Olefins , vo l % 5 2 0 1 2 Tgo , ° F 28 0 - 30 0 35 0 - 36 0 335 Target level s o

f aromatics an d olefin s wer e chose n t o approximat e th e 10t h an d 90t h percentil e value s fo rcommerciall yavailabl e summertim e fuel s fo reac h o f th e parameters
. MTB E was set a t 0 an d 1 5 volum e percent
. Th e hig h MTB E valu e correspond s t o 2. 7 weigh t percen t oxygen . Tg- , value s wer e chose n t o provid e a wid e enoug h rang e i n whic h t o identif yanypotentia l effects

. Al l blend s wer e formulate d fro m currentl yavailabl e refiner ystream s bu t d o not necessaril yreflec t fue l blend s tha

t ar e o rcoul d b e produce d i n volum e b yexistin g refineries

. Industr yaverag e fuel , whic h was als o blende d fro m existin g refiner ystreams , ma ynot b e representative o f fuel s actuall ysol d i n al l geographi careas an d ma ydiffe r fro m nationa l as wel l a

s regiona l "average " fuel s i n its specifi ccomposition

. Ther e ar e numerou s mean s o

fblendin g fuel s havin g th e gros s compositiona l characteristics indicate d above ; n o systemati ceffor t was mad e t o contro l fo rth e speciate d compositio n o fth e test fuels

. Th e formulatio n an d blendin g ofspecifi cprogra m fuel s i s a resul t o f th e statistica l desig n o

fth e experiment , whic h was intende d t o test th e effects o f extrem e value s o

fth e chose n parameters
. Target an d actua l propertie s o fth e individua l fuel s ar e show n i n Attachments IV an d V

. Al l fuel s wer

e teste d a

t leas t twice i n al l vehicles

. EExhaus t emission s wer

e measure d fo ral l test s accordin g t o federa l certificatio n test procedures

. Vehicle s underwen t additiona l tes t preparatio n cycle s whe n test fuel s wer e change d t o eliminate fue l carryove reffects (fue l carryove reffects ca n occu rwhe n switchin g fro m on e fue l t o anothe ri f th e previou s fue l i s not full yeliminate d fro m th e vehicle)

. Manyfuel/vehicl e combination s wer e teste d fo revaporative an d runnin g los s emissions

. I n certai n tests , detaile d speciatio n measurement s wer e mad e t o identif

y approximatel y150 individua l compound s presen t i n th e emissions

. These measurements wil l b e use d t o relate fue l compositio n t o emission s compositio n an d ai rquality

. RESULT S Result s ar e presente d i n thi s bulleti n fo rthre e responses : exhaus t mass emission s o fhydrocarbon s (HC) , carbo n monoxid e (CO) , an d oxide s o fnitroge n (NOx

) fro m ai l fuel s teste d i n th e curren t fleet an d fo rte n fuel s teste d i n th e olde rfleet (abou t halfo f th e fuels ; analysi s o n olde rvehicle s was not complet e a t th e tim e ofthi s bulletin)

. Mor e detaile d analyse s of th e exhaus t emission s results , as wel l as th e evaporativ e an dP. 6

runnin g los s emission s results , wil l b e presente d i n futur e bulletin s an d i n th e fina l report
. Othe rportion s o f Phas e I consis t o f testin g methano l fuel s i n Flexibl e an d Variabl e Fue l Vehicles , an d evaluatin g th e effect s o fothe rgasolin e parameter s (vapo rpressure , ethanol , ETBE , an d sulfur) o n emissions

. Thes e test s ar e currentl ybein g conducte d an d th e emission s results , a s wel l a s result s o f ai rqualit ymodeling , wil l b e presente d i n futur e bulletins

. Statistica l Analvsi s - Exhaus t emissio n result s are presente d i n tw o ways . First , th e mas s emission s wer e analyze d b yregressio n analysi s technique s usin g SA S (Statistica l Analysi s System ) compute rprograms . Thi s analysi s provide d estimate s of th e change s i n emission s du e t o changin g on e o rmor e o f th e fue l compositio n parameters
. Aful l analysi s i s possibl e onl yafte ral l fuel s i n th e factoria l experimen t hav e bee n teste d a s ha s bee n don e i n th e curren t fleet

. Fo rth e olde rfleet , however , wher e th e result s o f onl yhal f o f th e fuel s wer e availabl e fo ranalysis , i t wa s onl y possibl e t o estimat e th e effect of changin g on e compositiona l paramete ra t a time

. Becaus e onl ytw o level s o f eac h fue l facto rwer e studie d i n thi s factoria l design , quadrati ccurvatur e o rnon-linearityo f th e effect s canno t b e estimate d althoug h interactio n effect s ca n b e estimated

. Th e secon d analysi s techniqu e involve d calculatin g th e fleet average s fo reac h fue l an d th e confidenc e interva l associate d wit h tha t average . Becaus e multipl e comparison s wil l b e mad e amon g fuels , th e Tuke yMultipl e Compariso n Tes t wa s use d an d 95 % confidenc e interval s wer e calculate d fo rth e averages . A n analysi s o f th e dat a fro m th e curren t fleet indicate d tha t NO xemission s increase d a n averag e o f 4.7 % betwee n th e first hal f an d th e secon d hal f of th e testin g program . Thi s shift wa s significan t a t th e 99 % confidenc e limi t an d wa s take n int o accoun t i n th e regressio n analysis

. Th e result s show n i n Table s 1 an d 2 wer e correcte d fo rthi s shift s o tha t al l fuel s ca n b e compare d o n a n equivalen t basis

. Thi s behavio rwa s no t observe d fo rH C an d C O emissions

. Curren t Flee t - Th e regressio n analyse s evaluate d al l mai n facto rresponse s a s wel l a s al l possibl e two , three , an d fou rfacto rinteraction s amon g th e variables

. Mai n facto rresult s fo rth e curren t flee t ar e show n i n Tabl e 1 an d Figur e 1

.

• Mai n H C Response s - Individually , lowerin g aromatics , addin g MTBE , an d lowerin g Tg- , resulte d i n lowere d H C emissions

. Lowerin g olefin s raise d H C emissions

. Th e larges t singl e effect suggeste d b ythes e dat a wa s associate d wit h lowerin g T x fro m 36 0 ° F t o 28 0 ° F whic h reduce d exr.aus t mas s H C emission s b y22 % o n averag e fo r al l fuel s tested

. Thi s effect coul d als o b e th e resul t o f fue l compositiona l o rphysica l parameter s othe rtha n Tg-,

. Thes e result s indicat e th e nee d fo rfurthe rexaminatio n i n futur e phase s o f th e Program

.

• Mai n C O Response s - C O emission s wer e lowere d b yreducin g aromatic s an d b yaddin g MTBE

. Changin g olefin s an d reducin g Tg- , di d no t hav e a statisticall yP. 7

Emiwio n Constituen t H S

.. 2 NO x Tabl e 1

Mai n Effect

s OfChange s I n Fue l Variable s O n Mas s Exhaus t Emission s Curren t Vehicl e Fleet , (Percen t Change)
AROMATIC S 45%- * 20 % -6. 3 ±1. 8 •13. 6 ±2. 9 Z 1 ±2. 0 CHANG E I N FUE L VARIABL E MTB E OUEFIN S 0 % • * 15 % 20 % - » 5 % -5. 1 ±1. 8 6. 1 ±2. 0 •11. 2 ±3. 1 1. 5 ±3. 4 1.4 ±£ 0 4. 0 ±1. 9 T 9 0 360°F-» » 280° F -21. 6 ±1. 7 0. 8 ±3. 9 5. 0 ±2. 4
Now : Values are show n wit h 95 % confidence Intervals . Change s less tha n th e confidence interva l are no t signifioan L Note : A n 'affect* I s th e difference I n a response (HC . CO , NOx ) compute d usin g al l experimenta l desig n dat a as particula r variable s (aromatics , MTBE , olefins , Tgg) change . significan t impac

t o n C O emissions .

•Mai n NOxResponses - NOxemission s wer e lowered b

y reducin g olefins , raised whe n Tg o wa s reduced , an d only marginall y increase d whe n aromatics wer e lowered . Addin g MTB E di d no

t significantly affec

t NOxemissions . There appeare d t o b e significan t interaction s amon g fue l variables fo rHC , CO , an d NOxemission s a s show n i n Tabl e 2 an d Figur e 1 .

•Interaction s Affectin g H C - A t lo wvalues o

fTgo , neithe raromati c no r olefi n conten t ha d a n impac

t o n H C mass emission s whil e a t hig h level s o

fTgo , bot h variables ha d a n impact . Correspondingly , reducin g Tg o alway s lowere d H C emission s althoug h th e effec t depend s o n th e leve l o faromatics an d olefins .

•Interaction s Affectin g C O - Lowerin g aromatics whe n Tg o wa s hig h reduce d C O mor e tha n whe n T ^ wa s low. Reducin g Tg- , whe n aromatics were lo wraise d CO , whil e i t reduce d C O whe n aromatics wer e high .

•Interaction s Affectin g NOx- Althoug h th e singl e facto r(main ) effects o f aromatics an d MTB E o n NO xwer e slight o rinsignificant , there wa s a significan t interactio n betwee n th e two fue l variables . Addin g MTB E raise d NO xemission s whe n aromatics were low , an d conversely , reducin g aromatics raise d NOxemission s only whe n MTB E wa s present . Th e ful l regressio n equation s includin g th e interactio n term s are show n i n Attachmen t VI . Flee t averag e emission s ar e plotte d i n Figures 2 throug h 5 . Figur e 2 organizes th e fuel s b

y averag e mass exhaus t emissio n level s fo r HC , CO , an d NOx . Confidence interval s (95%) are show n fo r eac h fue l as wel l a s fo rindustr y averag e fue l t o whic h th e fuel s are compared . Where there i s n o overla p o ftest fue l an d industr

y averag e fue l confidence intervals , th e difference i s considere d significant .P. 8

Tabl e 2 Interactiv e Effect s O fChange s I n Fue l Variables O n Mass Exhaus t Emission s

Emissio n AROMATIC S Constituen t 45 % • * 20 % H C Lo wTg o 1. 7 ±2. 5 Hig h fg o -13. 2 ±2. 5

S S Lo wTg Q -8. 6 ±4. 1 Hig h tg o -18. 0 ±4. 1

NO K W/O MTB E -1. 5 ±2. 8 Wit h MTB E 5. 8 ±2. 8 Curren t Vehicl e Fleet , (Percen t Change) CHANG E I N FUE L VARIABL E MTB E OUEFM S 0 % -* •15 % 20 % • * 5%

Lo wTg Q 1. 2 ±2. 8 Hig h Tg Q 11. 0 ±2. 8
Aromatics Lo w Hig h Lo w Hig h Olefin s

Lo w Lo w Hig h Hig h

Lo wAromatics Hig h Aromatics

5. 2 ±2. 8 Lo

wAromatics •2.0 ±2. 8 Hig h Aromatics T 9 0 360°F-» » 280° F

-18. 3 ±3. 4 -30. 3 ±3. 4 -10. 5 ±3. 4 -23. 7 ±3. 4

5. 7 ±5. 5 -5. 1 ±5. 5

Note : Value s are show n wit h 95 % confidence intervals . Change s less tha n th e confidence interva l ar e no t significan t Note : A n 'effect* i s th e difference I n a response (HC , CO , NOx ) compute d usin g al l experimenta l desig n dat a as particula r variable s (aromatics , MTBE , olefins , Tgo ) change . Note : Th e tabl e show s al l statisticall y significan t multipl e interactions .
Figur e 3 als o organize s th e fuel s b y averag e mass exhaus t emissio n level s fo r HC , CO , an d NOx . I n thi s case , however , averag e confidence interva l bars (95%) are give n whic h ca n b e use d t o compar e an y tw o o rmor e fuel s fo rsignifican t differences . Fuel s separate d b

y mor e tha n th e lengt h o

fa ba rare significantly different . Figures 4 an d 5 illustrat e i n three dimension s th e relationshi p betwee n averag e HC , CO , an d NOxmass exhaus t emissio n level s an d fue l composition . Fuel s wit h MTB E are plotte d separatel y fro m fuel s without MTB E an d eac h fue l i s plotted accordin g t o it

s actua l aromatics , olefins , an d Tg o values . Averag e HC , CO , an d NOx level s are give n fo r eac h fue l (refe rt o Figures 2 an d 3 fo rth e significance o fth e values) . Emissio n result

s fo r individua l fuel s are consisten t wit h th e result s o fth e regressio n analysis .



### 6P. 9

A n indicatio n o

fth e linearit

y o fth e responses an d o fth e genera l applicabilit y o f th e regressio n equation s ma y b e obtaine d b

y determinin g th e abilit y o fth e regressio n equatio n t o predic

t th e emission s measure d fo r fuel s A (industr y averag e fuel ) an d B (emission s certificatio n fuel) . Result s o fthi s exercise ar

e show n i n Tabl e 3 .

Table 3 Regressio n Equatio n Prediction s Fo r Fuel s A an d B

Curren t Flee

t
Fue l A Fue l B

Statisticall y significan t value s a t th e 95 % confidence level . H C C O NOx Observe d

0.2 2 Z79 0.6 0 Predicte d

0.2 3 2.8 8 0.5 8 % Difference

-72* -3. 4 -1-2.6 Observe d

0.2 0 2.6 2 0.5 4 Predicte d

0.2 2 2.8 7 0.5 8 % Difference

-11.2 * -9.5 * -8.7 *

Th e difference betwee n actua l an d predicte d H C values fo rfuel s A an d B ma y b e attributabl e t o compositiona l properties othe rtha n thos e studie d i n thi s progra m a s wel l a s non-linearity . Fue l B , whic h was use d a s a reference fuel , wa s blende d to certificatio n test fue l standard s an d wa s produce d fro m entirel y differen t fee d stock s tha n othe r Progra m test fuels . Olde r Flee

t - Th e mai n facto r regressio n analysi s result s fo rth e olde rfleet o n halfo fth e fuel s are show n i n Figur e 6 an d Tabl e 4 . Th e analysi s includes fuel s tha t wer e a half-replicat

e o fth e 16-fue l factoria l design .

Emissio n Constituen t H Q S S NO K Mai n Effect s Of

AROMATIC S 45%- » 20 % 9. 8 ±4. 1 -4. 8 ±5. 4 -8. 4 ±2. 8 Tabl e 4

Change s I n Fue l Variables O n Mas s Exhaus t Emission s Olde rVehicl e Fleet , (Percen t Change )

CHANG E I N FUE L VARIABL E MTB E OLEFIN S 0%- » 15 % 20%-* > 5 % -7. 3 ±3. 5 6. 1 ±4. 0 -13. 0 ±5. 0 -0. 8 ±5. 7 -0. 6 ±3. 0 -8. 9 ±2. 8 T 9 0 360°F- » 280 V •1. 6 ±3. 7 13. 1 ±6. 5 3. 4 ±3. 1
Note : Value s are show n wit h 96 % confidence intervals . Change s lee s tha n th e confidence interva l are no t significan t Note : A n 'effect* I s th e difference i n a response (HC , CO , NOx ) compute d usin g al l experimenta l dat a as particula rvariable s (aromatics , MTBE , olefins , Tgo ) change .
Because onl y halfo

fth e fuel s hav

e bee n analyze d i n th e olde r fleet, estimates o fth e interaction s canno t b e mad e t o determin e i fth e effect

s ar e additive . Whe n th eP.1 0



### analysi s o f al l fuel s i s completed , interaction s ca n b e determined

. I t i s possibl e that th e value s o f th e response s ma

ychang e whe n th e ful l analysi s i s performed

. H C - Exhaus

t hydrocarbo n emission s wer e reduce d byaddin g MTB E an d wer e increase d bylowerin g aromatics an d olefins

. Lowerin g Tg o ha d n o statisticall ysignifican t effec t o n H C emissions

. C O - CO emission s wer

e lowere d byaddin g MTB E an d raise d bylowerin g TgQ

. Th e effects o

f reducin g aromatic

s o rolefin s wer

e not statisticall ysignificant

. NO x- NO xemission s wer

e lowere d b

yreducin g aromatic

s an d olefin s bu t wer

e raise d byreducin g TgQ

. Addin g MTB E di d not hav e a statisticall ysignifican t effec t o n NOx

. Th e regressio n equation s fo rth e mai n term s ar e show n i n Attachmen t VII

. Figure s 7 throug h 1 0 sho wth e fleet averag e results o fth e fuel s teste d i n th e olde rfleet. Th e figures ar e as describe d i n th e curren t fleet results except that fuel s whic h hav

e not yet bee n analyze d ar e show n withou t averag e emission s level s i n Figure s 9 an d 10

. Discussio n of Result

s - Mas s exhaus t emission s ofbot h curren t an d olde rvehicl e fleets wer

e affecte d bychange s i n fue l composition

. Responses t o change s i n olefi n an d MTB E conten t wer

e simila rfo rbot h fleets whil e response s t o change s i n aromatics an d Tg o level s wer

e different , an d i n certai n case s opposit e i n th e two fleets. Th e largest percentag e effec t i n th e curren t fleet, th e impac t o fTg o o n exhaus

t H C emissions , was not foun d i n th e olde rfleet. Th e reason s fo rth e impac t o ffue l compositio n parameter s an d especiall yth e interaction s betwee n the m ar e not yet full yunderstood

. The yma yb e related , i n part , t o th e chemica l compositio n of th e specifi crefiner ystream s use d t o blen d th e tes t fuels

. I n thi s par

t ofth e program , onl yfou rcompositiona l parameter s wer e systematicall y investigated

. A

s a n example , al l aromatic s wer e assume d t o behav

e i n th e sam e way , regardles s o

f molecula rweigh t o rstructure
. Differen t refiner yblend s migh t resul t i n fuel s wit h differen t detaile d composition s tha n thos e o fth e fuel s teste d i n thi s progra m an d hence differen t emission s performance

. Beyon d th e analyse s ofth e progra m desig n variable s (aromatics , MTBE , olefins , Tgo) , a preliminar

yexaminatio n ofliqui d fue l compositio n parameter s has reveale d that goo d statistica l correlatio n exists betwee n parameter s suc h as ligh t an d heav y aromatics , ligh t an d heav yolefins , etc
. an d mass emission s fo rth e curren t fleet. Characterizin g fue l compositio n i n term s o f thos e parameter

s ma yb e mor e usefu l i n correlatin g mass emission s tha n th e progra m desig n variables

. Furthe ranalyse s ar e planne d t o determin e th e mos t importan t compositiona l factors , t o determin e quantitativel yhowmass emission s respon d t o chemica l composition , an d t o estimate th e relative importance of chemica l compositio n an d physica l propertie s suc h a s distillatio n temperatures
. 8P.1 1



### Anothe rare a ofinevitabl e uncertaint ya t thi s tim e as t o th e relationshi p o f exhaus t emission s t o fue l compositio n i s th e fac t that onl ytwo level s ofeac h paramete rwer e teste d an d there i s n o wa yt o determin e whethe rth e respons e functio n ove rth e region s investigate d require s th e inclusio n ofhighe rorde r(curvature ) terms
. Th e tw o leve l factoria l design s employe d i n thi s stud yca n detec t interaction s betwee n factors , bu t not individua l curvature effects

. Futur e studie s ar

e planned

. Base d o n th e dat a availabl e fro m thi s portio n ofth e Program , a complet e analysi s ofwh yth e fleets responde d differentl yt o change s i n th e fue l compositio n ma ynot b e possible

. Ther

e wer e a numbe rof difference s betwee n th e fleets suc h as vehicl e mileage , catalyti cconverte rage , method s offue l meterin g (carburetio n vs . fue l injection) , an d th e employmen t of adaptive learnin g algorithms

. Thes e difference s ar e characteristi cofth e differen t vehicl e model s whic h distinguis h th e tw o fleet s an d wer e no t controlle d systematicall ybetwee n th e fleets. Ther e ar e a numbe rofothe rvehicl e factors whic h ma yaffec t emission s an d ai r qualit yan d whic h wer

e not teste d i n thi s par

t ofth e program . Al l tes t vehicle s ha d emission s level s that wer e simila rt o thos e i n EPA' s in-us e vehicl e fleet dat a base

. Th e progra m was no t designe d t o stud yvehicle s wit h hig h level s of emission s ("supe r emitters" , tampere d vehicles , etc.)

. I n addition , al l effects wer e instantaneou s effects

. Ther e are n o dat a o n th e lon g ter m effects of fue l compositio n change s o n catalyst durabilityan d emissions

. Thes e factors wil l b e examine d i n Phase I I ofth e Program

. Th e implication s ofthes e results fo rai rqualit ycannot b e evaluate d unti l th e ai r qualit ymodelin g effor

t i s completed

. Th e modelin g effor t wil l take int o accoun t evaporative an d runnin g los s emission s as wel l as exhaus t emissions

. I t wil l als o mak e us e of th e speciatio n measurements carrie d ou t i n man yofth e tests
. Result s o f th e ai rqualit ymodelin g wil l b e reporte d i n future Technica l Bulletins

. Th e estimate d cos t ofproducin g som e reformulate d gasoline s withi n th e Phase I matri xwil l b e determine d b ydevelopin g regiona l refiner ylinea rprogrammin g models

. Result s wil l b e reporte d a

t th e en d of Phase I followin g completio n ofth e ai rmodelin g studies

.p 1 ?



### FIGUR E 1 

# CHANGE S I N MASS EXHAUS TEMISSION S CURREN TFLEE T

% Increas e

% Decreas e

% Increas e

% Decreas e 2 0

1 0 0 •1 0 •2 0 •3 0 •4 0 

# + 1
a 

### EXHAUS

TH C

D 

# 1

* * « 

# 4"' ° TDIA. 0

# yAROMATIC

S MTB E OLEFIN S T9 0 45 % —20 % 0 —

15% 20 % —5% 36 0 F —28 0 F 

### EXHAUS TCO , NO

x

AROMATICS MTB E OLEFIN S T9 0 45%- * 20 % 0—15 % 20% —5% 36 0 F—28 0 F
A/ a - High/Lo wAromatic s O/ o - High/Lo wOlefin s T/ t - High/Lo wT9 0 

### NOTES : 1 . Square s represen t averag e effect s fo r al l fuel s 2 . Effect s fo r Aromatics , Olefins , T9 0 depen d o n level s ofothe r parameters , a s show n 3 . Bar s represen t 96 % confidenc e interval sP.1 3



### FIGUR E 2 

# MASS EXHAUS

TEMISSIONS , CURREN TFLEET

0. 3 0.2 8 0.2 6 0.24 0.22 0. 2 0.1 8 0.1 6 EXHAUS

TH C g/n H

0 H N

• c a P e » 

# llll l

• • l l l l l «

C M P 0 ' TTI 

# 4..\..L r L T1 

# in 1

IM0U1TB Y MIRM I
i — i i_

. t
. . . T

I I 1

/c x

1 1 —fc

.

3. 6 3. 4 3. 2 AaaAAaCAaaaaaAAA A M MMMMIncfllMrnfllMIWM M M f n OO00OOR0O0O00OO0 0 ttttttTtTtTTTTTT T EXHAUS T CO . a/m i

3 • U 2. 6 2.4 2.2 M J r

1 W 1 C ) 1

i l l I' i i 1 1

i ' » (

i i : c

i i j •

. ' • <

i i j

i i <

i i »
i i i 1 t

1 i

\ IN0U6TR V mvuat 1 ) 

# V I >c.i

aaaaaCaAaaAAAAAA A MMMMf n E fllMHIfllMMfflllinifll M oOOoOROoooOOoOOo o TTttTTttTttTttTT T 0. 7
03 6
0. 6

03 6 EXHAUS

TNOi , a/m l

1

i I O R 1 J F C KI (

i l r i ' i ' i i > i i )
i i I '
i r »
1 1 . « 1 

## l v ) » ( A
l 1
\ INDUSTR Y MWUOK H

I 

# V 

# r

CaAAaaAAAAAaaaaA a B f nM M M f nM f nft l M M f nM t nM f nM RoooooeoOOOOeOOO O TTTTTtttTtTttTTt t 

### A/ a * High/Lo wAromatic s M/ m - High/Lo wMTB E O/o - High/LowOlefi n T/ t - High/Lo wT9 0 CERT- Certificatio n Tes t Fue l Note : Confidenc e interval s ar e fo r Comparison s o

ftwo fuels . Pairs whic h d o no

t overla p are different .FIGUR E 3



# MAS S EXHAUS TEMISSIONS , CURREN TFLEE T

EU£]

_ A B C D E F G H 1 J K L M N O P Q R _£_=__

_ AV E CER T AMo t amO T AMO T amo t AmO t aMO t Amo T aMo T Amo t AmO T aMO T aMo t AMO t amO t amo T AMo T 

### 0.2 8 ( )



## o R 

### 0.26(h L

0.2 4 0 Q.E

0.2 2
0. 2
0.1 8 A

M.F. D K C.G.P. B O.H. N 

### 3. 3
3. 1
2. 9 ( )



### 2.7 i
2. 5
2. 3 O
( ) ( ) L.I. R

K. G E
A F. O P.C. Q B D H, N
O J. M 

### 0.6 6 r O H



### 0.62 ^ O P 

### 0. 6 0.5 8 0.5 6 ( ) Q 0.54(IJ B 

## 0.5 2 

# a Hi . O. E A C.K. L F J

H C , g/m i CO , g/m i NOx , g/m i NOTE : Bar s represen t averag e 95 % confidenc e interval s fo r compariso n o fpair s o ffuels . Fuel s separate d b y mor e tha n th e lengt h o fa ba rar e significantl y different . A / a - High/Lo wAromatic s M/ m - High/Lo wMTB E O/ o - High/Lo wOlefin s T/ t - High/Lo wT9 0 AV E - Industr y Averag e CER T- Emission s Certificatio n Fue lP.1 5

o r o o c n b r o t o o > - 4

C D 

## fi) 

## 0 )

C D 

# i f 

# 3 c n - 5 

# 3 

# 2.55 " C D ••< • } g 

# m

# J2 . O 3 0) p r o p b > c n r oa.


# FIGUR E 5 

# Mas s Exhaus t Emissions , Curren t Fleet 8 Fuel s Wit h MTB E (grams/mile) H C = 0.2 5 C O = 2.9 2 J* ^ NO x= 0.61>""A , , * ' , , ->« ^ 

## Z^\ 

## E ) 0.2 7 ^ ^ 3.16/—^ ^ 

## 0.5 7 

## U

0.2 0 2.6 8 S~\ 0.2 4 2.3 2 — 0.58^X ^ ( J 

### 0.1 9 V- ^ 2.7 4 ^~S

. 0.6 1 ( o )

0.5 9 (^Cj ^ 01 9 

### 45^J5^^ ^ 2.4 6 f ^**v*^ ^

0.6 2 ( h 

# Aromatics —^^ 1

20vol%^5vol% 0.1 9 

### 2.4 5 J •^^0.6 5 ( •

_-

0.2 1 ^-^2.3 8 

### I M J 0.6 4 360°F 

# T9 0

H ) J^T^80°F ^^20vol% 

# Olefin sFIGUR E 6



# CHANGE S I N MAS S EXHAUS TEMISSION S - OLDE R FLEE T

% Increas e 3 0

2 0

1 0



### % Decreas e H C C O NO x

- [ ] H C C O NO x

T 

### O

III I l\

i H C H C C O NO x

[ ]

" [ ] ( )

III I C O NO x

Z\


### O

i i - 1 0

2 0 AROMATIC S MTB E OLEFIN S T9 0 

### 45 % •- > 20 % 

### 0-*>15 % 20 % -• > 5 % 36 0 F -•

> 28 0 F NOTES : 1 - Analysi s o fvarianc e fo r hal ffactoria l

2 . Fue l variabl e effect s o n emission s ar e no t additiv e 3 . Bar s represen t 95 % confidenc e interva l fo r individua l effect sP.1 8



### FIGUR E 7 

# MASS EXHAUS

TEMISSIONS , OLDE R FLEET

o.s s

0.8 6

0.4 S • EXHAUS THC . fl/ml

0.3 8 c "

1 E a

i i n i 0 

# •fH 1 ? !

. > 

## ^ s i

" . INDUSTR Y vtntau j
i F 

# i A 

# i Ci .

A M 0 t A M 0 T m O t m 0 T M 0 t m o T M O t M 0 T m o t EXHAUST CO , g/m i

EXHAUS TNO» . g/n l



### A/ a - High/LowAromatic s Note : Confidenc e interval s ar e fo r M/m - High/LowMTB E comparison s o ftwo fuels . O/o - High/LowOlefin s Pairs whic h do no t overla p T/ t - High/LowT9 0 are different .

### FIGUR E 8



# MAS S EXHAUS TEMISSIONS , OLDE R FLEE T

fc-i-J-LI. A 

### c D E F Q H 1 J N &£. . AV E AMo t amO T AMO T amo t AmO t aMO t Amo T aMo T aMo t 

## 0.5 9



## o.syf F 0.5 5 0.53 $ 

## 0.5 1 0.49 ' 0.4 7 0.45(b E 

## d) C 0.4 3 J • N.I. A

UH. D O G 6.5^G* »
OF. A

5. 5 O H N C. D

4. 5 1.3 5 <) G 1. 3
1.2 5 () E



## 1. 2
1.1 5 <) C () H () D O l ( ) A 1.1(J N ( ) J O F 

### 1.0 5 L 

### HC , g/m i CO , g/m i NOx , g/m i NOTE : Bar s represen t averag e 95 % confidenc e limit s fo rcompariso n o fpair s o ffuels . Fuel s separate d by more tha n th e lengt h o fa ba r ar e significantl y different . A/ a - High/Lo wAromatic s AV E - Industr y Averag e M/ m - High/Lo wMTB E O/ o - High/Lo wOlefin s T/ t - High/Lo wT9 0

C O

# FIGUR E 9 

# Mas s Exhaus t Emissions , Olde r Flee t 9 Fuel s Withou t MTB E (grams/mile )

H C = 0.5 3 C O = 6.4 9 NO x= 1.13 1 I

45 vol% 

# Aromatic s 280°F 0 vol% 

# Olefin s

T l h o

# FIGUR E 1 0 

# Mas s Exhaus t Emissions , Olde r Flee t 8 Fuel s Wit h MTB E (grams/mile ) H C = 0.4 5 C O = 4.7 9 NO x= 1.27 /
' E )

0.5 4

4.6 9 1.0 8



### 45 vol% 

# Aromatic s 280°F 20 vol% 

# Olefin s 20 vol%^5 vol%

u hoATTACHMEN TI 

# AI R QUALIT

YIMPROVEMEN TRESEARC H PROGRAM PHAS E I RESULT

S PUBLICATION S

PROGRA M MATRI X
CURREN TFLEE T REFORMULATE D GASOUN E
OLDE R FLEE T REFORMULATE D GASOUN E
FLEXIBLE

/ VARIABL E FUE L METHANO L 

### EXHAM5 T
TECHNICA L BULLETI N # 1
TECHNICA L BULLETI N # 1 (PARTIAL

) RESULT S CATEGOR Y

EVAPORATIV E RUNNIN G LOS S AI R MODELIN G FUEL S
SA E 90209 8

SA E 90209 8

SULFU R

RVP / OXYGENATE S

ro roVeh .

OI A 01 B 02 A 02 B 03 A 03 B 04 A 04 B 05 A 05 B 06 A 06 B 07 A 07 B 08 A 08 B 09 A 09 B 10 A 10 B
Key : Mfr . Chrysle r Chrysle r Chrysle r Chrysle r For d For d For d For d For d For d Toyot a Toyot a Hond a Hond a G M G M G M G M G M G M 

### M<* W ATTACHMEN TI I



## Curren t Mode l Fleet Vehicle s
Displ . Yea r Liters Sundanc e 198 9 Sundanc e 198 9 Shado w Shado w Mustan g Mustan g Tauru s Tauru s Aerosta r Aerosta r Camry Camry Accor d Accor d Suburba n Suburba n 198 9

198 9 198 9 198 9 198 9 198 9 198 9 198 9 198 9 198 9 198 9 198 9 198 9 198 9 Gran d A m 198 9 Gran d A m 198 9 Delt a 8 8 198 9 Bonnevill e 198 9

T C - Turbocharge d TB I - Throttl e Bod y Injectio n PF I - Por

t Fue l Injectio n SF I - Sequentia l Fue l Injectio n Carb . - Carbureto r 2. 5 2. 5 2. 5 T C 2. 5 T C 5. 0 5. 0 3. 0 3. 0 3. 0 3. 0 2. 0 2. 0 2. 0 2. 0 5. 7 5. 7 2. 3 2. 3 3. 8 3. 8 

## 10,00 0 t o 29,00 0 Mile s

Fue l Svste m TB I TB I PF I PF I SF I SF I PF I PF I PF I PF I PF I PF I Carb . Carb . TB I TB I PF I PF I SF I SF I Ai r

EG R Iniectio n Ye s Ye s N o N o Ye s Ye s N o N o N o N o Ye s Ye s Ye s Ye s Ye s Ye s N o N o Ye s Ye s

Ai r - Secondary Ai rInjectio n Pai r - Pulse d Ai r Injectio n N o N o N o N o Ai r Ai r N o N o N o N o N o N o Pai r Pai r Ai r Ai r N o N o N o N o Catalvs t TW C TW C TW C TW C 2TWC&20 C 2TWC&20 C TW C TW C 2TW C 2TW C TW C TW C TW C TW C TW C TW C TW C TW C TW C TW C

TW C - Thre e Way Catalys t O C - Oxidatio n Catalys t Locatio n C C C C U B U B CC&U B CC&U B C C C C U B U B C C C C U B U B U B U B U B U B U B U B



### cc U B - Clos e Enoin e Famil v

KCR2.5V5FBD 6 KCR2.5V5FBD 6 KCR2.5V5FAC 3 KCR2.5V5FAC 3 KFM5.0V5HBF 4 KFM5.0V5HBF 4 KFM3.0V5FEG 0 KFM3.0V5FEG 0 KFM3.0T5FYK2 KFM3.0T5FYK2 KTY2.0V5FFF X KTY2.0V5FFF X KHN2.0V2F4F 6 KHN2.0V2F4F 6 K3G5.7T5TYA 3 K3G5.7T5TYA 3 K2G2.3V8XEW 0 K2G2.3V8XEW 0 K2G3.8V8XEB 1 K2G3.8V8XEB 1

Couple d Unde r Bod yVeh . Mfr .

20 A Chrysle r 20 B Chrysle r 21 A For d 21 B For d 22 A For d 22 B For d 23 A Hond a 23 B Hond a 24 A G M 24 B G M 25 A G M 25 B G M 26 A G M 26 B G M Displ .

Mode l Yea r Liters Relian t 198 5 Relian t 198 5 Temp o 198 5 Temp o 198 5 F-15 0 198 3 F-15 0 198 3 Accor d 198 5 Accor d 198 5 Gran d Pri x198 4 Cutlas s 198 4 Impal a 198 5 Capric e 198 5 Suburba n 198 4 Suburba n 198 4
Note : * Ope n loo p contro l system . Key : TB I - Throttl e Bod y Injectio n Carb . - Carbureto r 2. 2 2. 2 2. 3 2. 3 4. 9 4. 9 1. 8 1. 8 3. 8 3. 8 5. 0 5. 0 5. 7 5. 7 ATTACHMEN TII I 

## Olde r Mode l Flee t Vehicle s 42,00 0 t o 79,00 0 Miles

Fue l Svste m Carb . Carb . TB I TB I Carb. * Carb. * Carb . Carb . Carb . Carb . Carb . Carb . Carb * Carb. * Ai r

EG R Iniectio n Ye s Ye s Ye s Ye s Ye s Ye s Ye s Ye s Ye s Ye s Ye s Ye s Ye s Ye s

Ai r - Secondary Ai r Injectio n Pair- I Pulsed Ai r Injectio n Ai r Ai r Ai r Ai r Ai r Ai r Pai r Pai r Ai r Ai r Ai r Ai r Ai r Ai r Qatarys

t TW C TW C TWC/O C TWC/O C O C O C TW C TW C TWC/O C TWC/O C TWC/O C TWC/O C O C O C

TW C - Thre e Way Catalyst O C - Oxidatio n Catalyst Locatio n C C C C U B U B U B U B U B U B U B U B U B U B U B U B

C C - Clos e U B - Unde r Enain e Famil y

FCR2.2V2HDH 5 FCR2.2V2HDH 5 FFM2.3V5HCF 4 FFM2.3V5HCF 4 DFM4.9T1ADF 9 DFM4.9T1ADF 9 FHN1.8V3FXF 5 FHN1.8V3FXF 5 E4G3.8V2NEY 0 E4G3.8V2NEY 0 F1G5.7V4NEA 4 F1G5.7V4NEA 4 E1G5.7T4HHC X E1G5.7T4HHC X

Couple d Bod y •

, .
% *

_,

•

## QQP E A B C D E F G H 1 J K L M N O P Q R 

## J__

L AV G CER T AMo t amO T AMO T amo t AmO t aMO t Amo T aMo T Amot AmO T aMO T aMo t AMO t amO t amo T AMo T ATTACHMEN TI V



## COMPOSITIONA L MATRI X FUE L PROPERTIE S AROMATIC S % 

### 3 2 3 5 MA X 4 5 2 0 4 5 2 0 4 5 2 0 4 5 2 0 4 5 4 5 2 0 2 0 4 5 2 0 2 0 4 5 

## » - TARGE T

MTB E % 

### 0 0 1 5 0 1 5 0 0 1 5 0 1 5 0 0 1 5 1 5 1 5 0 0 1 5 OLEFIN S

% 

### 1 2 1 0 MAX 5 2 0 2 0 5 2 0 2 0 5 5 5 2 0 2 0 5 2 0 2 0 5 5 ^9 0



## ° F 33 5 330/32 5 28 0 36 0 36 0 28 0 28 0 28 0 36 0 36 0 28 0 36 0 36 0 28 0 28 0 28 0 36 0 36 0

. AL L FUEL S AR E 8. 7 PS I RV P AN D CONTAI N N O ETHANO L O R ETHANO L COMPOUND S •A/ a - HIGH/LO WAROMATIC S •M/ m - HIGH/LO WMTB E
• O/o - HIGH/LO W OLEFIN S
• T/ t - HIGH/LO W Tgj ,

T l

. h o c n

### CQDf E

A B C D E F G H 1 J K L M N O P Q R

. A/a -

. M/m -

. O/ o - •T/t - 

## _IQ

AV G CER T AMot amO T AMO T amot AmOt aMO t AmoT aMo T Amo t AmO T aMO T aMo t AMO t amO t amo T AMoT ATTACHMEN TV 

## COMPOSITIONA L MATRI X FUE L PROPERTIE S - AROMATIC S % 

### 32. 0 29. 9 43. 8 20. 7 43. 7 20. 0 44. 3 20. 2 42. 9 21. 4 45. 7 47. 8 18. 0 21. 4 46. 7 20. 3 21. 5 46. 0 HIGH/LO WAROMATIC

S HIGH/LO WMTBE HIGH/LO WOLEFINS HIGH/LO WT ^ SE E SA E 90209 8 FO R MORE DETAIL

S MTB E

% 

### 0 0 15. 4 0 14. 8 0 0 14. 6 0 14. 9 0 0 14. 5 13. 9 14. 6 0 0 15. 2 

## ACTUAL

OLEFIN S % 

### 9. 2 4. 6 3. 3 22. 3 17. 2 3. 2 17. 4 20. 2 4. 1 4. 0 4. 9 17. 7 21. 8 5. 7 19. 3 18. 3 4. 8 4. 0 T 

### 9 0

° F 33 0 30 9 28 8 35 7 35 7 27 9 28 6 28 6 35 3 35 6 29 4 35 7 35 6 29 2 28 3 28 4 35 7 35 4 RV P



## PSI 8. 7 8. 7 8. 7 8. 5 8. 7 8. 8 8. 8 8. 5 8. 9 8. 6 8. 8 8. 5 8. 7 8. 8 8. 6 8. 5 8. 6 8. 4 *

•

t

### Attachmen t V I P.2 7



## Curren t Flee

t Tabl e ofRegressio n Coefficient s

R 2 Std

. Erro r Variabl e Mean(1 ) 

### A M 0 T A M A O A T M O M T O T AM O AM T AO T MO T Bloc k 

### a

o
« i 

### -h. % 3 4 3 1 2 3 1 3 31 4 % 3 32 4 ^3 4 3 12 3 3 12 4 3 13 4 323 4 3i2a

_ 

### H C

0.982 7 0.082 9
-1.511404 2 0.0025823 * -0.0034959 * -0.0039509 * 0.0030304 * 0.000103 6 -0.000011 7 0.0000795 * 0.000100 9 0.000017 9 -0.0000764 * -0.000011 1 -0.000002 7 -0.000001 0 0.000001 0 -0.008772 8 

### C Q 0.972 3 0.147 1
1.008286 3 0.0058362 * -0.0079158 * -0.000967 9 -0.000104 9 0.000074 9 •0.000082 9 '#0.0000542 *
' " 0.000001 2 -0.000006 7 -0.000058 8 -0.000013 2 0.000001 9 -0.000002 2 0.000001 5 0.005037 9 NO x

0.988 3 0.086 5
-0.506667 6 -0.000813 2 0.000950 9 

### 0.0041530 * -0.0006042 * -0.0001905 * -0.000019 1 -0.000010 9 -0.000129 8 0.000004 4 0.000018 7 0.000002 3 0.000003 0 -0.000001 6 0.000002 1 -0.001485 8



### * = Significan

t a t th e 95% confidenc

e level . (HC , CO , NOx

) EX P [a , + a , * (A ) + a - * (M ) + a , * (O ) + a 4 •(T ) + a, a * (AM ) + a, , * (AO ) + a, 4 * (AT ) + a, , * (MO ) + a * •(MT ) + a * * (OT

) + a, a * (AMO ) + a, * * (AMT ) + a, * * (AOT

) + a- ^ •(MOT) ]
where , A •(

% Aromatic s - 328 ) M = ( % MTB E - 7.37 ) O = » ( % Olefins - 11.8 ) T- (T , - 321 ) (32.8 , 7.37 , 11.8 , 321 ) mea n value s o fAromatics , MTBE , Olefins , an d T ^ respectively , fo r th e 1 6 factorial * fuel s (fuel s C •R) Bloc k > •0. 5 fo r Bloc k + 0. 5 fo r Bloc k Exampl e o

finteractio n terms : A M « A * M = (

% Aromatic s - 328 ) * ( % MTB E •7.37)

### Attachmen t VI I 

## Olde rFlee t Tabl e Q f Regressio n Qn*m r 

### \an^ Preliminary

, Base d o n Bloc

k I Fuels Onl

y 

### HQ_ R 2 Std . Erro r Variabl e Mean(l ) * 

### A M __f\ 

### 0 T i

3

o a i 3 2 3 3 3 4 0.975 9

0.097 2

-0.69635 2 -0.003742 * -0.005089 * -0.003975 * 0.00020 2 

### -GO . 0.953 2 0.147 1

1.72278 4 0.00195 6 

### -0.009269 * 0.000539 -0.001537 *

*

_ 

### NO x 

### 0.9840 0.0790
0.16466 7 0.003526 * -0.000383 0.006212 * -0.000416 *

= Significan t a t th e 95 % confidenc e level . (HC , CO , NOx

) - EX P [a- + a , * (A

) + a , * (M) + a , * (0 ) + a , •(T)]
A M , 0 , Tar

e define d a s for Curren

t Vehicle Flee

t Equations . Thi s equatio n is simpler tha n reporte d herei n for th e curren

t vehicle flee

t becaus e onl y hal fo f th e 1 6 fuel s ar e include d an d onl y th e mai n effect

s A, M . O , an d Tca n b

e determined ."n-?jp '(ATittc'cA'A/- X '"MJ

. • t'.; . .''„••_!'. ' .-..

•);%7.-.<. - •"-.* : '•" : > ^ i-> 3 P.2 9

«*. - X.r;- i