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# OAR Box 1852 Prepped byKeeiaRichards



### Document

Number: 

# 38 ) ll-C-1 4 Docket Number: 

# A-86-0 3

Printed 11/19/20082:38:54

PM Sheet 38of 101P. 2

' * ^ * \

UNITE D STATE S ENVIRONMENTA LPROTECTIO N AGE N 

# ussy

AU G 7198 7

MEMORANDUM 

### A-8<r--C> 3 

# DRAF T
AN N ARBOR

. MICHIGA N 4810 5 

# H © H 0w AUG - 9 1989 OFFIC E O F AI R AN O RADIATIO N



# ^ Ui vj£it 

# £ Qf len t

SUBJECT : Effec t o f Fue l Sulfu r o n Engin e Wear/Engin e Lif e
FROM :
TO :
THRU : Timoth

yL . Sprik , Chemica l Enginee r Standard s Developmen t an d Suppor t Branc h Charle s L . Gray , Jr. , Directo r Emissio n Contro l Technolog yDivisio n TomDarlington , Mechanica l Enginee r ' XHA A *3b\JcA~*(ftr\^ Standard s Developmen t and Suppor t Branc hJ Richar d A . Rykowski , Senio r Projec t Mange r Standard s Developmen t and S^*pport y Branc h Cheste r J . France , Chie f Standard s Developmen t an^/frupp , Th e purpos e o f thi s mem o i s t o summariz e th e result s o f a studycontracte d t o SwR I on th e effec t o f fue l sulfu r on engin e wea r and engin e life
. Th e draf t repor t receive d fromSouthwes t Researc hInstitut e too k tw o approache s i n analyzin g th e effec t o f sulfu r o n engin e wear . Th e firs t approac hwa s t o analyz e al l availabl e dat a in th e literatur e investigatin g th e relationshi p betwee n engin e wea r an d fue l sulfu r content , operatin g condition s (load and speed) , an d engin e temperature . Th e second approac hwa s t o evaluat e oi l analysi s dat a obtaine d fromdiese l fleet s operatin g i n California' s Sout hCoas t Ai r Basi n (SCAB ) befor e and afte r legislatio n reducin g th e sulfu r conten t t o 0.0 5 weigh t percen t wen t int o effec t i n January , 1985
. Compariso n analysi s o f oi l iro n conten t befor e and afte r th e impose d sulfu r reductio n wa s anticipate d t o giv e an indicatio n o f th e impac t o f sulfu r o n wea r unde r "rea l world " operatin g conditions
.P. 3

-2

- Literatur e Searc h Th e literatur e searchdon e b ySouthwes t wa s mor e comprehensive than an ypreviousl yundertake ni n the are a o f sulfur an

d engin e wear . However , mos t o f the dat a relating sulfur t o engin e wea r wa s ol d (1940' s an d 50's ) and, ^ du e t o th e differenc e i n oi l qualities , pas t an d present , canno t b e applied quantifiabl yt o curren t engines
. Anothe r limitatio no f mos t o f th e literatur e dat a i s tha t th e impac t o f sulfur o n engin e wea r wa s addresse d unde r carefull ycontrolle d stead y stat e conditions , an d no t in-us e transien t conditions
. On e sourc e i n the literatur e whic hdi d tak e al l o f thes e parameter s int o accoun t wa s th e docke t submitta l o f Mercede s Benz . Wea r testing wa s performe d o n a Mercede s Ben z 0M42 2 engin e ( 4 stroke , DI , naturall yaspirated , 14. 6 liter ) operating on AP I C C 2 0 W2 0 oil
. Th e oi l wa s change d frequentl yt o retai n resolutio n o f the experimenta l measuremen t technique , an

d therefor e ther e wa s n o significan t TBN depletion
. Th e wea r effect s o f fuel s wit hsulfur level s o f 0.2 6 an d 0.0 5 weigh t percen t wer e investigated ove r a rang e o f engin e operating condition s (load , speed , temperature)
. Reduce d corrosive wea r wa s observe d during condition s typica l o f col d star t an

d warm-u

p conditions
. Fo r instance , a t coolan t temperature s o f 122°F , an8 0 percen t reductio ni nbor e wea r wa s observed
. At 158°F , th e reductio n wa s onl y2 8 percent , an d a t 176°F , ther e wa s n o differenc e i nthe observe d rate s o f wea r fo r th e differen t fuels
. At eve n highe r temperatures , th e low sulfur fue l actuall yshowed a sligh t increas e i nwear . Mercede s the n develope d a mathematica l correlatio no f wea r vs . engin e operating , fuel , an d oi l parameters , whic hagree d wel l wit hth e tes t data
. Southwes t di d not , however , attemp t t o us e thi s equatio n t o determin e the overal l wea r reductio nwhic h woul d b e seen in engine s unde r a variet yo f operating conditions
. Thi s exercis e mayb e possibl e t o perfor min-house , however , i n orde r t o determin e th e impac t o f th e rat e o f warm-u p (a s i t relate s t o ambien t temperatures ) o nwea r i n conjunctio n wit hth e finding s o f th e flee t oi l analysis
. Th e fina l conclusio n o f Southwes t wit hregard t o th e literatur e search , however , wa s tha t th e interrelationshi p o f engin e operation , fue l quality , oi l alkalinity , an d temperatur e wa s to o complex , an d tha t n o quantificatio n o f th e effec t o f fue l sulfur reductio n o nengin e lif e wa s possible
. Use d Oi l Analysi s Th e investigatio n o f Southwes t int o oi l analysi s dat a i n th e SCA

B prove d t o b e somewha t mor e fruitful
. Four loca l southern Californi a fleet s wer e abl e t o suppl yoi l analyse s fro mbefor e an

d afte r th e implementatio n o f 0.0 5 sulfur legislation
. Th e larges t o f thes e fleet s wa s th e Sout hCoas t Rapi d Transi t Distric t (SCRTD) , whic hoperate s 250 0 transi tP. 4

-3

- buse s powere d b

yCummins , Detroi t Diesel , an d MA Nengines
. Abou t 30,00 0 oi l analysi s record s wer e available , fro m198 4 (pr e 0.0 5 sulfur ) an d 198 5 an

d 198 6 (pos t 0.0 5 sulfur) , o f whic happroximatel y700 0 wer e delete d du e t o suspecte d recordin

g errors . Sulfur level s o f th e fue l wer e 0.3 5 wt . percen t in 1984 , an d 0.0 3 (0.02 ) wt . percen t i n 198 5 (86)
. Given thes e sulfur levels , a naverag e 3 0 percent"reductio n in oi l iro n conten t wa s seen betwee n198 4 an d 1985-86
. I t shoul d b e pointe d ou t that , a s expected , no t al l operatin

g parameter s wer e constan t during thi s thre e yea r period
. Ne woi l TBN , a measur e o f th e oi l alkalinity , increased fro

m5. 4 i n 1984 , t o 7. 4 (6.1 ) i n198 5 (86)
. Use d oi l TB Nvalue s wer e 4.4 , 5.8 , an d 6. 0 respectively
. Fromthi s paramete r only , one woul d expec t t o se e a decreas e i n corrosiv e wea r rate s i n 1985-86 , an d therefore , th e reductio ni n oi l iron conten t coul d b e partiall yattributabl e t o this
. Considering this , th e wea r rat e reductio n determine d fro mth e dat a wil l arguabl yb e maximum
. Also , curren t nationa l fue l sulfur level s ar e aroun

d 0.2 5 wt . percent , an d therefore , rule s limiting sulfur conten t t o 0.0 5 woul d onl yexperienc e 6 2 percen t o f th e sulfur reductio n experience d i nth e SCRTD fuel
. Adjustmen t t o the result s t o incorporat e thi s differenc e i s als o necessary . I n spit e o f thes e problems , however , th e primaryadvantag e o f the SCRTD flee t oi l analysi s dat a ove r experimenta l studie s i s tha t th e oi l analysi s procedur e measure s tota l iron wor ni n th e engin e a s oppose d t o measuring onl yring and/o r line r wea r (a s i n the experimenta l studies)
. According t o a 198 1 EM A rebuil d survey , los s o f oi l contro l i s a majo r facto r i n deciding whe n an engin e i s rebuilt
. Thi s los s o f oi l contro l can come abou t throughsevera l mechanisms , including (1 ) abrasive wea r o f th e cylinde r fro m pisto ndeposits , (2 ) ring scuffing fro

moverfueling an

d overheating , (3 ) broke nrings , an d (4 ) corrosive wear . Fortunately , al l o f thes e wea r mechanism s resul t i n wea r particle s being deposite d i nth e oil , an d ar e therefor e accounte d for i n th e comparativ e oi l iron analysis
. Th e percentag e reductio n i n oi l iron conten t ca n therefor e b e directl yrelate d t o a decreas e i ncombustio n chambe r wea r and , consequently , a decreas e i noi l consumption
. Dat a fro

mth e othe r thre e SCA B fleet s wer e les s reliabl e since : 1 ) n o fue l analysi s dat a coul d b e provided , 2 ) th e numbe r o f sample s wer e significantl yles s ( a tota l o f onl y abou t 200 0 fo r th e othe r thre e fleet s combine d a s compare d t o abou t 30,00 0 for SCRTD) , an d 3 ) ther e wa s a significan t increas e i n th e level s o f zin c presen t i nth e oi l i n 1985-8 6 compare d t o 1984
. Zin c dithiophosphat e (ZDTP ) i s wel l establishe d a s a

n inhibito r t o abrasive wear , an d i t i s therefor e difficul t t o determin e the relative contribution s o f th e zinc increas e an d th e sulfur decreas e t o th e reductio n i n wea r observed
. Southwes t di d conclud e tha t theyfee l th e zinc increas e di d no t contribut e significantl yt o th e reductio n i nP. 5



### -4

-

wear , bu t thi s clai mwa s no t wel l supporte d an d therefor e th e dat a fro

mSCRTD shoul d b e considere d preferentially
. Considering al l o f th e oi l analysi s data , however , Southwes t di d conclud e tha t i t appeare d tha t a significan t decreas e i n oi l iron conten t wa s observe d wit h„lower sulfur fuel
. However , theyfel t tha t thi s reductioni nwea r coul d no t b e extrapolate d t o engin e life , an d therefor e n o quantitative statemen t abou t th e effec t o f desulfurizatio no nengin e lif e wa s made
. In summary , the Southwes t repor t di d no t discus s adequatel yho wt o relat e th e finding s o f th e literatur e searc h an d oi l analysi s t o engin e life , an d consequentl ylef t th e issue unresolved
. Afte r conversatio n wit hthe Southwes t staf f member s responsibl e for th e repor t an d othe r member s o f industr yfamilia r wit hthe issue , however , a n interna l approac h wa s develope d fo r using th e dat a t o quantif ypotentia l increase s i n engin e life
. Thi s i s describe d generall yi nth e followin

g paragraphs , an

d a nexampl e calculatio nfo r buse s i s outlined i n Appendi xA . Interna l Approac ht o Estimating Wea r Benefit s Our approac huse s the flee t oi l analysi s data , wit hth e primar yissu e being ho wt o relat e a percentag e decreas e i n engine wea r product s (iron ) t o anincreas e i nflee t lifetime VMT and , consequently , a saving s t o owners/operators
. Th e firs t are a o f focu s i s t o determin e th e actua l reductio ni n wea r rates . Sinc e th e bul k o f th e dat a i s take n fro m two-strok e Detroi t Diese l engines , man yo f th e iro nwea r particle s ar e los t du e t o th e highoi l consumptio n o f thes e engines
. I n othe r words , th e concentratio no f iron i n th e oi l mayno t increas e linearl ywit htime , bu t mayreac han "equilibrium " valu e wher e th e rat e o f ironi nequal s th e rat e o f iron los t i n th e consume d oil
. Th e analysi s wa s don e tw o ways . On e waywa s t o compar e absolut e value s o f ironi nth e oil , independen t o f mile s o n th e oi l sample , an d th e othe r wa s t o normaliz e iron conten t b yth e mile s o n th e oi l sample , giving "iron pe r mile " values
. Ther e wa s littl e differenc e i n th e fina l result s betwee nthes e two methods
. Compariso no f wea r rate s befor e an d afte r th e sulfur reductio nwer e made , an d a percentag e reductio n wa s determined
. Th e nex t step wa s t o translat e thi s percentag e reductio n i n wea r rat e t o a

n extensio n i nvehicl e life
. Arebuil d survey don e b yEM Awa s obtaine d fro mwhic hth e fractio no f rebuild s necessitate d b

ylos s o f oi l control , blowby , an d poo r oi l analysi s (al l a functio n o f cylinde r wear ) wa s estimated
. Th e wea r benefi t wa s the n applie d t o onl ythos e engines
. Engine s whic hfaile d fo r othe r reason s (se e Appendi xA ) wer e assume d t o receive n o benefit
. Vehicle s remove d fro mth e flee t b

ycrashe s likewis e receive d n o benefit
. Thes e extension s i n vehicl e lif eP. 6

-5

-

wer e the n pu t i n terms o f a saving s i nowners ' cos t i nterm s o f dollar s pe r mile
. Fo r buse s thi s resulte d i nan extensio n o f abou t 6 percen t i n lifetime vehicl e mileage , an d a reductio ni n yearl yoperating cost s o f abou t $67 2 (1.50/mil e o r 80/gallon)
. I t shoul d b e note d tha t the bul k o f thi s cos t benefi t result s fro mth e fac t tha t the lif e benefi t i s claime d onth e entir e vehicl e chassi s (=$150,000)
. Wer e th e benefi t claime d onl y o n th e engin e (-$15,000) , th e saving s woul d onl yb e abou t $10 0 pe r yea r (^It/qzl). Othe r calculation s ar e show n i n th e Appendi xA . Probabl yth e mai nquestio n involved wit hthi s analysi s i s whethe r th e SCRTD flee t dat a shoul d als o b e use d fo r HDD an d LDD analysis
. The majorit yo f th e SCRTD dat a i s take n fro mDD A two-strok e enqine s operating a s transi t buses , an d mayno t b e applicabl e t o line-haul , mediu mduty , an

d ligh t dut y operation
. Dat a fro mth e othe r two Californi a fleet s (show n i n Appendi xB ) showvarying results
. Th e renta l truc k flee t generall yconfirms the SCRTD results
. Th e Chandle r flee t show s a n increas e i n oi l iron conten t wit hlowe r sulfur , whic hw e ar e currentl yattributing t o th e smal l sampl e siz e i n198 4 versu s 198 5 an d 198 6 or perhap s error s i nanalysi s or reporting (sinc e othe r sample s ar e generall yi ngoo d agreement)
. Th e reductio n i nline hau l engin e wea r rates , however , woul d probabl yb e differen t fro mtha t see nfrombuses
. Firs t on e woul d expec t t o se e highe r averag e operating temperature s i n line-hau l engines , a t whic hi t appear s tha t th e effec t o f sulfur i s muc hless
. Also , a t hightemperatur e operation , formatio n o f pisto n deposit s increases , whic hwoul d increas e the rat e o f abrasive wear . Areductio n i n corrosive wea r woul d therefor e represen t a smalle r fractio no f th e tota l wear , an d th e overal l effec t o f a sulfur reductio nwoul d b e less
. O nth e othe r hand , oi l consumptio ni n 4-strok e engine s woul d b e expecte d t o b e les s thantha t seeno n th e 2-strok e engine s investigated
. Frequen t replenishing o f th e 2-strok e engine s oi l supply , therefore , migh t insur e tha t oi l TB Nneve r drop s t o critica l levels
. Pursuing thi s logic , i t migh t b e expecte d tha t 4-strok e engine s operat e o nlowTBNoi l mor e frequently , an d woul d therefor e b e mor e sensitive t o th e sulfur leve l i n th e fuel
. Anothe r facto r whic hcomplicate s th e analysi s i s th e fac t tha t th e ambien t temperature s experience d b ythe SCRTD flee t ar e highe r than thos e experience d b ymos t diesel s i nth e nation
. Engine s i n colde r climate s mayspen d mor e time operating a t lowcoolan t temperature s wher e th e corrosiv e problemi s exacerbated
. Hence , engine s i ncolde r climate s may se e a greate r benefi t fro ma fue l sulfur reductio n tha nth e SCRTD fleet
. Clearly , th e questio no f applicabilit yo f th e SCRTD dat a t o non-bu s application s i s complex
. However , a t thi s point , sinc e th e larges t an d mos t reliabl e dat a bas e o f oi l sample s take n wer e fro mSCRTD buses , i t ha s bee n preliminaril ydecide d t o us e thi s dat a fo r al l engine s instead o f dat a fro

m th e smalle r fleets
.P. 7
Appendi xA : Extensio n o f Engin e Lif e

Methodolog

yo f Calculation s Analysi s o f SCRTD Dat a a . Assumption s i
. Th e oi l use d i n1984 , 1985 , an d 198 6 wa s sufficientl yalkalin e (4. 4 - 7. 4 TBN ) fro m on e oi l chang e t o the next . Althoughaverag e TB N increased i n 85-8 6 b yabou t l TBN , th e level s wer e always withi nmanufacture r recommende d levels , an

d sinc e i t appear s TBNoperate s o na "threshold " effect , i t shoul d no t significantl yaffec t th e differenc e betwee n8 4 an d 85-8 6 wea r levels
. ii
. Th e iron i nth e oi l i s al l derive d fro m th e liner , rings , pistons , etc . SwR I agree s wit h thi s assumption
. An ydifference s see ni nth e oi l iron conten t represent s a direc t percentag e reduction i n cylinde r liner , bore , an d rin g wear , whic hshoul d correlat e wel l wit hengin e life
. (I f thi s assumptio nwer e fals e [i.e. , < 10 0 percen t o f ironcame fro m cylinder ] the na percen t reductio ni n iron betwee n198 4 an

d 1985-8 6 woul d correspon d t o a greate r percen t reductio n i n cylinde r wear , assuming tha t corrosiv e wea r wa s th e onl y differenc e betwee n 198 4 an d 1985-86)
. iii
. Oi l consumption , o naverage , wa s th e same al l thre e years . iv
. a ) Ironwea r normalize d t o oi l mile s

assume s lo

woi l consumptio n(i.e. , littl e dilutio nb

yadditio n o f fres hoi l t o the crankcase)
. b ) Iron wea r no t normalize d assume s high oi l consumptio n (i.e. , th e ironleve l reache s anequilibriu mvalue , wher e iro n i n = iron burne d wit hconsume d oil , an d therefor e doe s no t chang e wit hmileage
.P. 8

Percen t Reductio n i n IronConten t Normalize d t o Oi l Mile s From

SCRTD Dat a % o f Sample s 0.7 7
52. 6
45. 6
1.0 3 Enqin e

CUV90 3
DDV7 1
DDV9 2
MAN86 6 Yea r

8 4 8 5 8 6 8 4 8 5 8 6 8 4 8 5 8 6 8 4 8 5 8 6 Sample s

8 7 7 3 1 5 205 4 511 1 483 6 45 8 438 7 555 1 5 9 6 7 11 0 Iron(p

p (xlO 1 ) 6.27 7 8.21 0 6.89 9 12.54 3 8.83 5 9.61 1 ^13.31 6 8.05 1 8.50 1 14.34 3 24.54 8 24.01 3 Iron(ppm)/Mil e %Reductio n (xlO 1 ) Iron(ppm)/Mi l

-30. 1

- 9. 9 2 9 2 3 3 9 3 6 -71. 2 -67. 4 2280 8 Adjus t % Reductio n t o Nationa l Sulfur Leve l Chang e

d
. % o f Sample s 52. 6
45. 6

e . Yea r

198 5 198 6 Avg . % Re d

Iron(ppm)/Mil e

Percen t Reduc t (assuminq Engin e DDV7 1
DDV9 2
Adjus t % (hig hoi l
Yea r 198 5 198 6 Avg . hiq

h
Yea r 8 4 8 5 8 6 8 4 8 5 8 6 32. 6 28. 0 30. 3 ion i n Iron % Re d a t

0.238^-0.0 5 Sulfur 19. 2 16. 0 17. 7
Conten t fro

mSCRTD Dat a oi l consumptio n o nDDV7 1 an d DDV92 ) Sample s 205 4 511 1 483 6 45 8 438 7 555 1 Iron %

(ppm ) Reduce d 82. 1 63. 6 22. 5 66. 2 19. 3 82. 1 50. 1 39. 0 51. 6 37. 2 Reductio n t o Nationa l Sulfur Leve l Chanqe consumption ) % Re d Iron 30. 2 27. 6 28. 9 % Red a t

0.238+0.0 5 Sulfur 17. 7 15. 7 16. 7P. 9

2 ; Applicatio n o f cylinde r wea r reductio nt o engin e lif e extensio n
a . Fractio n o f rebuild s cause d b yrin g & line r wea r i
. EM

Arebuil d criteri a survey(flee t survey ) Frequencyo f Reason s Cite d % % Criteri a Oi l Consumptio n Ma j Engin e Failur e Reductio n i nOi l Press . Blowb y Los s o f Performance / Reduce d Powe r Mile s Oi l Analysi s Compressio n Pressur e Engin e Hrs . Year s i n us e Tota l Response s Fractio n o f Engine s no t i
. Vehicl e Crashe s o f Fleet s Citinq 8 0 6 5 6 2 5 7 4 6 3 2 2 2 1 8 9 6 39 7 rebuil t 20. 2
14. 4



### 5. 5

40.1 % (36.3%) *

FromMVM

Afact s an

d figures , 1986 , assuming al l vehicle s no t surviving yea r numbe r on e ar e totale d crashes , Cras hRat e =0. 3 percen t pe r yea r HDD

0. 7 percen t pe r yea r LDDT 0. 4 percen t pe r yea r LDD V

Owne r Operato r SurveyP.1 0

ii
. Chassi s Failur e I t wa s assume d tha t scrappag e du e t o chassi s failur e wa s minimal , an d sinc e n o dat a coul d b e foun d concerning this , failur e rat e = zero . Operating Cost s - Urba n Bu s Lifetime Mileag e Miles/yea r Vehicl e Lif e (yrs ) Discoun t Rat e Baselin e 540,00 0 45,00 0 12. 0 10 % Discounte d Lifetime Mileag e 320,29 0
Overhau l Mileag e t o 1s t Overhau l Year s o f Operatio n Befor e Overhau l Fractio n o f Vehicle s Purchase d Remove d b

yCrashe s befor e 1s t overhau l Cos t o f Overhau l ($ ) Presen t Valu e Cos t o f Overhaul($ ) Coac h(w/Engine ) Cos t (new ) ($ ) Tota l Presen t Cos t Lifetime Operating Cos t ($/mile ) Operating Cos t Reductio n ($/yr ) 304,00 0 6.7 6

0.020 3 5,000.0 0 2,571.8 7 150,00 0 152,571.8 7 0.476 4 0.0 5 Sulfur :

574,686 * i 45,00 0 i 12.7 7 10 % 330,39 9
325,57 7 7.2 4

0.021 7 5,000.0 0 2,453.3 5 150,00 0 152,453.3 5 0.461 4 (-0.0149 ) 672.0 1

Assuming a 17. 7 percen t decreas e i n cylinde r wea r an d accounting fo r additiona l vehicl e crashe s an d vehicl e failure s du e t o non-oil-control-relate d reason s during the additiona l VMT fo r vehicle s benefiting
.P.1 L

- 1 % o f Flee t 20. 7
31. 7
47. 6

2

3 % o f % Re d Flee t 12. 6
50. 1
4. 5
0. 8
32. 0

4 . Eng :

Ca t Appendi xB : Dat a Fro m Chandle r

m e

Cummin s

DDA

.

• Y r

8 4 8 5 8 6 8 4 8 5 8 6 8 4 8 5 8 6 Summary :• Truc k

Sample s 6 5 4 8 2 5 7 4 13 8 2 2 11 9 18 5 68 5 Othe r SCAB Fleet s Flee t Engine s Iro n (ppm ) 72. 9 78. 2 50. 4 9. 8 17. 2 21. 6 53. 2 55. 5 62. 3 Iron(ppm)/M i

(xl0 J ) 24.5 7 46.7 7 48. 5 1. 9 3. 8 4. 9 13. 3 12. 1 14. 7
Chandle r Flee t Yea r 198 5 198 6 Avg . % Re d

Iro n -27. 5 -39. 9 -33. 7 % Re d

Iron/Mil e -46. 1 -75. 2 -60. 7

Renta l Truc k Flee t Engine s
Enqin e Cummin s

DD A

Deut z
GM C

I- H Y r

8 4 8 5 8 6 8 4 8 5 8 6 8 4 8 5 8 6 8 4 8 5 8 6 8 4 8 5 8 6
Summary : Sample s

3 8 3 4 5 1 12 6 16 2 20 0 8 1 6 2 0 2 2 4 9 0 11 4 10 8 97 5 Ren t a Yea r 198 5 198 6 Avg . Iro n

(ppm ) 34. 8 32. 5 37. 3 85. 3 62. 9 56. 4 128. 3 82. 3 102. 1 31. 0 18. 0 8. 7 72. 0 53. 8 49. 3 Iron(ppm)/M i

(xlO 3 ) 3.1 3 2.7 6 2.8 2 10. 7 8. 3 6. 7 16. 8 9. 7 13. 6 4. 4 2. 6 1. 5 11. 6 9. 0 8. 2
1 Truc k Flee t % Re d Iro n 24. 1 27. 6 25. 9 % Re d

Iron/Mile s 22. 1 30. 7 26. 4 l e % Re d

Iro n -7. 3 30. 9 -75. 5 -120. 4 -4. 3 -17. 1

l e % Iro n I
6. 6 -7. 2 26. 3 33. 9 35. 9 20. 4 41. 9 71. 9 25. 3 31. 5 % Re d

Iron/Mil e -90. 3 -97.4 4 -10 0 -15 8 9. 0 -10. 5

Re d ron/Mil e
11. 8 9. 9 22. 4 37. 4 42. 3 19. 0 40. 9 65. 9 22. 4 29. 3P.1 2



## 1 V

AU G

## 7 193 7

Dear : Bnclosedfo

r your revie

w ar e copie s o f thre e report s whic h wil l pla

y animportan t col e inour understandingo f the cost s an dbenefit s o f controllingthe qualit y o f on-highway

diese l fuel . Pleas e provid e u s withyou r comment s o a the enclose d report s withi nth e next thirty

days , a s w

e planon incorporatingth

e result s o f thes e report s i nour stud y o f diese l fue l qualit y to be publishe dson*tia e thi s fall . The enclose dstuo y fro m Bonne r * Moor e Managemen t Scienc e i s a draf t repor t whic hshow s th e result s o f thei r nationwid e refinery

modeling . The acceiingwa s conducte dt o determin e the nationwid e refinery cos t fo

r controllingbot hdiese l fue l sulfur conten t a s wei l a s sulfur an daromatics , conten t simultaneously . W e specificall y

reques t your consent s inthe followingtw

o areas : 1 ) The industries ' abilit y t o segregat e on-highway

diese l fue l fro m othe r distillat e products , an d2 ) th e estimate s of th e investment s requiredt o hydrotrea t the controlle ddistillat e poo l voluaea . \ Als o enclose di s the Southwes t researc hInstitut e repor t entitled , "stud

y of th e affect s o f Reduce dDiese l Fue l Sulfur Conten t onEngine Hear. " The repor t suwaariae s th e result s o f thei r literatur e searcho nth e effec t c f fue l sulfur o nengin e wear , an

dgive s a sumcary c f th e analysi s of engin e oil s taken fro a Sout hCoas t Ai r Basi n(SCAB ) fleet s fro m bot hbefor e an

d afte r fue l sulfur regulation . Th urepor t conclude s tha t ther e appear s t o b

e a reductioni

noi l iro

nconten t coincidingwit h lower fue l sulfur levels . Pleas e commen t o nthe content s i f thi s report , particularl y the finuingof th e oi l analysi s an d th e suamary

an dconclusions .P.1 3
Th e thir d itemi s a memorando mdescribin g a preliminar y ec:tempt t o appl yth e result s c f th e SCAB flee t oi l analysi s t o th e expecte d lif e ar. d cost s associate d wit hownin g and operatin g urba n transi t buses
. Pleas e provid e comment s o n th e methodolog yuse d i n thi s analysis , particularl ywith-respec t t o th e relativ e contribution s o f corrosiv e an d abrasiv e cylinde r wea r t o los s o f oi l control , and th e applicabilit yo f applyin g dat a take n from

buse s t o line-hau l engin e operation
. Than k yo u i n advanc e fo r you r cooperation
. Sincerel yyours ,

Charle s L . Gr ; _ Directo r Emissio n Contro l TechnologyDivisio n Enclosure stam P.1 4 |BBgiat{ j

Mr . Bruc e I . Bertelse n MECA 100 1 Connecticu t Avenue , N.W . Suit e 83 0 Washington , D C 2003 6
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W Washington , DC 2003 6 Associatio n

Mr . Marce l Halberestad t Moto r Vehicl e Manufacturer s Associatio n 30 0 Ne wCente r Buildin g Detroit , M I 4820 2

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W Washington , D C 2000 5

Mr . Chri s Weave r Radia n Corporatio n 1039 5 Ol d Placervill e Rd
. Sacramento , CA9582 7

Mr . Thoma s C . Youn g Executiv e Directo r Engin e Manufacturer s Associatio n 1 Illinoi s Cente r 11 1 Eas t Wacke r Driv e Chicago , I L 6060 1