# De v e lopment and Evalua tion of Color ado’ s Lo w Emitter Inde x

Colorado Department of Public Health and Environment May 2007

Pr ep ar ed b y : Mobi le So u r ce s Air Poll utio n Control Divi sio n Col o ra do De p a rtm ent of Pu bli c Healt h a n d Environ m e n t and Peter M McClintoc k , P H

. D

. Appli ed A naly s i s 891 Tib u ron B l vd. Peter. mc clintock@ comcas t. netz Page 2

### Introductio n C o lor a d o ’ s insp ec tion an d ma in te na nce ( I/M) pr og ra m inc l ud es a C l e a n Scre en ele m en t tha t allo ws vehi cle owne rs the o p tio n o f bein g exem pted f r om th ei r re qu ired I/M 240 i n sp ecti o n , if their ve hi cle i s dete r mi ne d cl ean. Cu rrentl y , to q ualify a s cl ea n a veh i cle m u st b e seen by a Re m o te S e n s i ng Device (RS D) a mi ni mum of two ti me s wit h in 1 2 month s p r i o r t o its req u i r ed I / M24 0 in sp e c ti on, wit h emi ssion s mea s urem ent less th an 20 0 ppm an d .5% for HC an d CO re sp e c tively. The Colo ra do De pa rtm ent of Publ ic Heal th an d Envi ro nme n t (CDP H E) i s p r o p o s i n g to a dd a hy bri d meth od of i d entifyin g cl ea n vehi cl es t h at co mb i n e s a si ngl e clea n RS D me a s ureme n t wit h a Lo w Emitter I ndex (LEI) crite r i o n. The LEI qua lifie s ve hi cles a s Cl ea n Scree n ca ndi date s b a s e d on a hist orically low prob ability of emi s sions f a ilure fo r simi lar vehi cles. The ad diti on of the LEI hybri d meth od wil l in crea se th e p r odu ctivity of t he existi ng Cl ean Scree n p r o g ram an d a llo w m o re ve hicle owne rs to take adva n ta ge o f the co nven ie nce of cl ea n scree ni ng witho u t jeop a r di zi n g the be nefit t o the cu rre n t I/M p r og ram. T he LEI q ualifi c ati on crite r ia will be eval uat ed /upd ate d o n a n a n n ual ba si s t o en su re it i s e q ual to or bette r than th e cu rre n t 2-hit cle an scree n p r o g r a m
. Col o ra do’ s I/ M prog ram i s inclu d e d in b o th th e O ne Ho ur O z o ne Maint e n a n c e Plan an d Eig h t Hou r Ozone Early Ac tion Compac t (EA C), as a mobile s o urce co ntrol st ra tegy. The p r og ram as m o del ed prohi bit s Co lo ra do from ev alu a tin g mo re than 50% of the I/M eligi b le fle e t. The incl usio n of the proposed LEI hybrid m e thod will not ex ceed thi s threshol d. Thi s do cume nt d e s cri b e s ho w t he LEI wa s d e velo pe d a l on g wit h the comp a r i s on of th e p r oj ect e d pe rfo r ma n c e o f the hyb r id m e tho d to th e curre n t 2
- hit Cl ean S c re en m e tho d

. 

### Source Data and Vehicle Grouping An LEI lo o k u p tabl e h a s bee n d e vel o p ed u s i ng 20 0 5 an d 2 0 0 6 i n itial IM 24 0 i n spe c ti on re sults. Col o ra do te st s A W D a nd t r acti on cont rol vehi cle s on 4 W D dy ne s so there a r e fe w mod e l s th at d o not r e c e ive IM24 0. Vehi cl es are g r o u p ed u s i ng:

- Col o ra do 1 Vehi cle Type: LDG V, LDGT 1, LDGT2, HDG T 1, HDGT 2

- Mod e l Ye ar: t he te nth ch arac ter from the VIN

- Mak e : dec od ed fr om th e VIN;

- Model: decoded from the VI N;

- Engi ne Di spl a ce me nt: de co ded f r o m the VIN; Only g r o u p s contai ni ng 2 0 o r mo re ve hi cle s wi ll be reta i ned i n the co mbin ed profile in orde r to a v oid concerns over stati s ti cal v a ri ability i n smal l sampl e si zes. Missour i had used t he fi rst fi ve characters of the VIN i n lie u of Make a nd Mod e l. Colo rado prop o s e s usi ng M a ke and Mod e l a s de cod ed f r o m the VIN us in g th e Po lk pr og ra m, s i nc e th is app ro ac h ap pe ars to b e tter a n d mo re c ons iste n t ly d i ffe r e n t ia te Ma ke/M od el t han t he Mi sso uri ap proa ch.

1 In the Col o ra do d a ta, li ght t r u cks a r e d e fi ned u s in g fou r types: LDGT 1 , LDGT2, HDGT1, an d HDGT2. The firs t pair roughly c o rresponds to the E PA’ s LDGT1 and the sec o nd pair corresponds to EPA’s LDGT 2.

z Page 3Tabl e 1 co mp ares t he u s e o f alternativ e sets of L EI vehi cle grou pin g s
. It sho w s the num be r of so urce vehi cle s , th e n u mb er of bin s with 20 o r m o re re sult s, an d the p e rcenta g e of all so urce vehi cle s in th ese cla s sifi catio n s. Cove ra ge of so urce veh i cle s i s hi gh est wit h the prop ose d sch e m e
. Tabl e 1 LEI Vehi cl e Grou pin g s Vehi cl e s > = 2 0 Bins HC /CO Fail % NOx Fail % HC /CO + N O x Fail % Fleet Cov e r a g e % No ne (All ve hi cle s ) 1,55 7,5 0 9 N / A 2

. 6 7 % 0

. 1 6 % 2

. 8 3 % 1 0 0 % Veh. Type, Model Year , Firs t 5 VIN Char., Polk Engine Di spl a ce ment, # of Cyli nd ers 1,43 9,3 8 2 8 ,43 8 2

. 5 4 % 0

. 1 6 % 2

. 7 % 9 2

. 4 % Veh. Type, Model Year , Firs t 5 VIN Char., Polk Engine Di spl a ce ment 1,45 0,5 1 8 8 ,38 8 2

. 5 3 % 0

. 1 6 % 2

. 6 9 % 9 3

. 1 % Veh. T y pe, Model Year , P o lk Make, Polk Model, Pol k Engine D i sp la ce ment 1,47 6,8 4 2 6 ,81 7 2
. 5 8 % 0.16 % 2.74 % 94.8 %

The LEI tab l e gen e r ate d u s i ng 20 05/ 20 06 I/M test re sult s wil l typically be ap pli ed to vehi cle s in spe c te d in 20 07 and pa rt of 20 08. Col o rad o ha s a fo ur-y e a r exem ptio n for ne w vehi cl e s . Althoug h som e in sp ec tio n s on th ese mo dels a r e per for m e d , the 20 05 /2 0 0 6 ins p ec tio n r e su lts may le a v e ga ps in th e profile fo r m o del s that will be fo ur -ye a r o l d vehi cl e s in 200 7/2 0 0 8 , e. g. 20 03 a nd 2 004 mod e l s . The gaps will be fi l l ed t o a lar ge extent by assumin g newer year vehi cles, wil l perform similarly (or bet ter) than t he sam e mo del of a n ea rlie r ye a r , for wh ich p e r fo rma n c e stati s t i cs a r e avai la ble, e. g. 2 0 0 3 and newer A c ura MDX s will perform at le ast as well as 2002 Acura MDX s
. 

### LEI Emissions Perfor m ance The val u e s l i sted bel o w we re co mput ed f o r ea ch ve hi cl e g r o up. T h e ave r a g e ex cess emi s si on s pe r vehi cle a r e the su m of the vehi cl e emi s sio n s ex ce ed ing the Colo ra do sta n d a rd s divi ded by th e nu mbe r of vehi cle s i n the g r o up. T h e s e g/ mi val u e s a r e u s uall y small co mp ared to g/ mi stand ard s be ca use mos t ve h i c l es d o no t a d d any e x c e ss emiss i ons a nd a ll vehi cl es are in clud ed i n the d eno min ato r
.

- Initial test s

- HC/CO fails

- HC/CO fail %

- NOx fails

- N O x Fail %

- Overall fail %

- Avera ge Ex ce ss HC g/ mi p e r vehi cl e

- Avera ge Ex ce ss CO g/m i pe r vehi cl e

- Avera ge Ex ce ss NOx g/mi p e r ve hi cle The LEI cl ea n scre eni ng eff e ctiv en ess wi ll be ta rget ed toward s th e m o st criti c a l p o ll utant s by a d ju stin g the sel e cti on crite r ia. F i g u re 1 A p l o t s the c u mu la tive p e rc en tag e o f e x c e ss emiss i o n s vs . th e p e rc e n t a g e o f veh i c l es w hen LEI g r o u p s are ran k ed by ta ilpip e emi s sio n s fail rate. Fi gu re 1B i s t h e same cha r t with a n ex pa nd ed y
axis. Th e s e cha r ts in di cate wh en g r o u p s of vehi cl e s a r e ran k ed by in crea si ng tail pi pe f a il rate, g r oup s co ntai nin g 7 0 % of the ve hi cle s prod u c e only 1 0 % of t he ex cess HC and CO a nd 30% of th e ex ce ss NOx. Note that total ex c e ss NO x i s sm al l com p a r e d to exce ss HC a nd CO d u e to Colo ra do’ s le nie n t N O x s t an da rds

.

z Page 4Figur e 1 A LEI Exce ss Emis sion s v s . % o f Vehi cles When Ranked b y Tailpipe Fail Rate


### Inde xed by Tai l pipe Fail Rate

0% 20% 40% 60% 80% 100%

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 % of Vehicle s% of Excess Emissions E xce ss HC % E xce ss CO% E xce ss NOx%

Figur e 1 B LEI Exce ss Emis sion s v s . % o f Vehi cles When Ranked b y Tailpipe Fail Rate


### Inde xed by Tai l pipe Fail Rate

0% 5% 10% 15% 20% 25% 30%

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 % of V e hic l e s% of Excess Emissions E xce ss H C % E xce ss C O % E xce ss N O x%

z Page 5Figu res 2A a n d 2B sh ow th e cum u lative p e r cent ag e of ex ce ss emi s si on s v s . t he pe rce n tag e of ve hi cl es wh en LEI g r ou ps a r e ra n k e d by the fail rate for HC o r CO. Seventy pe rcent of the ve hi cle s p r od uce 8% of the ex cess HC an d CO. Figur e 2 A LEI Exce ss Emis sion s v s . % o f Vehi cle s When Ra nk ed b y HC/CO Fai l Ra te


### I n d exed b y H C / C O Fail Rat e

0% 20% 40% 60% 80% 100%

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 % o f Vehi cles% of Excess Emissions E xce ss HC % E xce ss CO% E xce ss NOx%

Figur e 2 B LEI Exce ss Emis sion s v s . % o f Vehi cle s When Ra nk ed b y HC/CO Fai l Ra te 

### Indexed by H C /C O Fail R a t e

0% 5% 10% 15% 20% 25% 30%

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 % of V e hic l e s% of Excess Emissions E xce ss HC% E xce ss CO% E xce ss NOx%

z Page 6Figu res 3A a n d 3B sho w th e cu mul a tive p e r cent ag e of ex ce ss e m i s sio n s vs. th e p e rce n tag e of ve hi cl es wh en LEI grou ps are ran k ed by exce ss HC. Seventy p e rcent of th e veh i cle s prod u c e 5% of the excess HC

. Figur e 3 A LEI Exce ss Emis sion s v s . % o f Vehi cle s When Ra nk ed b y Excess HC 

### Indexed by Excess H C

0% 20% 40% 60% 80% 100%

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 % of Vehicle s% of Excess Emissions E xce ss H C % E xce ss C O % E xce ss N O x%

Figur e 3 B LEI Exce ss Emis sion s v s . % o f Vehi cle s When Ra nk ed b y Excess HC 

### Indexed by Excess H C

0% 5% 10% 15% 20% 25% 30%

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 % of V e hic l e s% of Excess Emissions E xce ss H C % E xce ss C O % E xce ss N O x %

z Page 7

### LEI Clean Screen Selection Crit eria To m a int a in fl exibility i n the sel e ctio n of LEI vehi cles (both quantity and quality), it i s suggest ed t hat the follo wi ng five crite r ia be co nsi d e r ed. Col o rad o is p r o p o si ng u s in g o n ly the HC/CO Fai l Rate crite r i a howev e r t he remai n i ng four will conti n ue t o be cal c ulat ed and if necessary i n cluded as part of future LEI table s
. Overall tailpi p e fail rate is less than: X% HC/CO Fail Rate is less than Y% Exc e ss HC is less than: A g/mi Exc e ss CO is less than: B g/mi Exc e ss N O x is less than C g/mi To ig no re on e or m o re of th e crite r i a , eith er a hig h o r a low v a lu e is e n tered. F o r e x ampl e, to sel e ct a ll vehi cle cl a s se s with a n ove r all fail rat e of l e ss th an 1%, entrie s wo uld be 1%, 9 9 %, 99, 9 9 an d 9 9

. Avera ge ex ce ss emi s sio n s pe r vehi cl e rel a te mo re di re ctly to ma ss e missi on s b e n e fits th an fail rate. Given two g r o u p s of v ehi cl e s with t he sa me fai l rate, o ne grou p co ntaini ng po or fu el e c on omy v ehi cl es and o n e g r o u p co ntai nin g g ood fu el e c o n o my ve hi cl es, the grou p wit h the p o o r f uel econ omy v ehi cle s will cont ribute greater excess emi s si ons. However, usi n g fail rate as t he criteria i s easi er for the m edi a and t he p u b l i c to un de rstan d

. 

### Hybrid Met hod Evalua tion The hyb r id me thod of sele cti ng ve hi cle s fo r cle an scre en wa s evalu a te d usi ng 20 06 d a ta. I/M re sult s of vehi cle s t hat wo uld hav e b een sele ct ed usi ng t he hyb r id met h o d a r e co mp ared t o the re su lts of the 5 % aud it sam p le of vehi cl e s p a s sin g th e cu rrent 2-hit sc ree n a nd v ehi cl e s th at we re id entifie d as cle an (2
- hits) b u t fo r un kn o w n re ason s di d n o t pa rti c ipate i n th e cu rrent cle an screen prog ram. Tabl e 2 b e lo w sh o w s that proje c t ed re sults f o r veh i cl es sele ct ed u s in g th e hyb r i d met h o d co mpa r e favorably t o t he cu rre n t RSD 2
- hit met hod. B o th t h e tail pip e a n d ove r all f a il ra tes, wh ich i n clud e s evap orative t e st fail u r e s , a r e 0.3% l o we r. Th e hyb r i d meth od was mod e le d u s i n g RS D CO a nd HC cut poi nts of 0. 5% an d 2 0 0 p p m re sp ectiv e l y and a si mpl e LEI HC/CO fa il rat e of 2%. Tabl e 2 Clea n Scre en M e th od Ev aluatio n Summary

Method Sam p le Num b er of Vehicl es IM24 0 Tailpipe Fail Ra te Ov erall I/M Fail Rate

H y brid Sample 31,6 4 4 0

. 3 4 % 2

. 6 % 200 6 RSD 2- h i t 5% Audit S a m p le 1,50 9 0

. 4 6 % 2

. 5 % Other RS D 2 - hit Sam p le M e e t ing Scre en Cri t er ia 15,2 9 9 0

. 6 6 % 2

. 9 %
Com b ine d R S D 2 - hi t Sam p les 16,8 0 8 0

. 6 4 % 2

. 9 %

z Page 8The re sult s sh ow th at the ef fective n e s s of the hybri d m e tho d is e quiv a le nt to that o f the cu rrent clea n scree n in g m e thod u s in g two RS D me a s u r e m ent s. Fu rthe r i n ve sti gatio n i s b e in g co nd uct e d to d e te rmi n e if the evap o r ativ e fail u r e s can be cost effe cti v ely re du ce d f o r b o th meth od s by a pplyi ng a n a dditi on al rest ri ctio n on cle a n scree n s for m ode ls with a patte rn of eva p o r ative t e st f a ilu re s. The re mai n d e r of thi s se cti o n provid e s d e tail s of the hyb r id eval uati on. H y brid Ev alu a tion Process As n o te d ab ov e, the hyb r id meth od of sel e cti ng v ehi cl e s fo r cle an screen wa s eval u a ted u s in g 2 0 06 I/M re su lts of vehi cle s th at wou l d hav e be en sele cte d u s i ng t h is meth od. Vehi cl e o w n e rs a r e notifi ed of thei r cle an scree n eli g i b ili ty one to t w o mont hs p r io r t o thei r re gi stratio n re ne wa l date. Cha n g e of o w ne rshi p vehi cl es th at are in spe c te d off-cy cl e are, the r ef ore, not ab le to t a ke adva n ta ge of cle a n scree n i ng. Hist oricall y , vehi cle s ch ang in g o w ne rshi p hav e h i g h e r e m i s sio n s an d failu re rat e s th an othe r ve hi cles. To a c cu ra tely p r oj ect hy bri d cle an screen p r o g ram pe rfo r ma n c e t h e s e off-cycle t e sts a r e remov e d fro m t he eval uatio n samp le . T o accomp l i sh thi s , vehi cl es te ste d i n 2 0 0 6 we re sel e ct ed whe r e t hei r f i rst te st o ccurre d withi n 2 3
- 25 mont h s of thei r fi rst te st in 2 0 0 4

. T h is ide n tifie d 30 3, 525 v ehi cl e s test ed with IM 2 40. RS D me a s u r e m ent s from th e 12 -m ont h wind ow i n a d va nce of th e IM 240 t e st we re identifi ed fo r the 303, 52 5 veh i cl es. Of th e s e, 23,5 21 ve hi cl es ha d at le a s t two m e a s u r e m ent s a nd 48, 438 v ehi cl e s h a d a si ngl e m e a s ureme n t. Vehi cl es with two me a s u r e m ent s woul d typically be con s id e r e d fo r cu rre n t 2
- hit scree ni ng met hod

. Vehi cl es t hat accepte d th e cle an scre en optio n wo ul d not typi ca lly h a ve a n IM2 4 0 test in 20 06 and, therefo r e, are not typi cally incl ud ed i n t he ext r a c te d sa mpl e of ve hicle s with t w o me asu r em e n ts de scri be d a b o v e. The extra c te d sam p le o f vehi cle s with two m e a s ure m ent s d o e s i n clu de t he 5% aud it sa mpl e , vehi cl es th at did n o t pass th e scre en, vehi cl e s th at did n o t accept the cle an scree n opti on and vehi cle s fo r which th e se co nd q ualifyi ng RS D may n o t have b e e n in time to b e in clu d e d b e fo re the proce s sin g d e adli ne. Vehi cl es with a si ngl e me a s ureme n t pa ssed th e hyb r id metho d if th eir HC an d CO emi s si on s we re bel ow 2 0 0 p p m and 0.5% respe c tive ly on their RS D me asurem ent a n d thei r LEI g r o up h ad a n HC/CO fail rat e of le ss tha n 2%. Result s are co mpa r e d to bot h the 5% a udi t sam p le a nd t he oth e r RS D 2-hit vehi cle s scree ned u s in g the cu rre n t 2-hit m e tho d

. Since ve hicle s with t w o q uali f ying me a s u r e m ent s wo uld not b e eli g ibl e for th e hyb r id meth od th ey we re not co n s id e r e d p a rt of t he hybrid eval uat ion. Ho we ve r, vehi cl es fro m thi s grou p t hat wo ul d h a v e m e t the 2-hit RS D scree n crite r ia p r ovid e an oth e r po int of refe re nce f o r com p a r i s o n with th e eff e ctiv en ess o f the hyb r i d me thod. Th e r ef ore, re sults f o r three sa mpl e s are con s i d ered in th e fol l owin g cha r ts and table s :

• 200 6 RSD 2-h i t Audit sam p l e

• Hybrid Method sample

• Othe r RS D 2
- hit sa mpl e ; vehicle s wit h two RS D mea s u r em ent s that met the 2
- hit scree n criteria. Figu re 4 sho w s th at MY di st ributi o n s of veh i cl es me etin g t he scree ni ng crite r ia f r o m th e ‘ H yb rid S a m p le ’ and the ‘ O ther 2-Hit S a m p l e ’ vehi cles are simil ar to the ‘Audit S a m p le ’ except t hat the ‘Audit Sample’ inclu d e s mo re 200 2 mod e l s
. Most 20 02 m ode ls we re no t tested i n 20 0 4 an d, as a re sult of th e sa mple

z Page 9s e lec t ion me th o d de scr ib ed ab o v e , were no t inc l u ded in th e ‘H ybr i d Sa mp le’ or the ‘O th er 2
- h i t Sampl e ’. Sin c e th e 2 0 0 2 mod e l s a r e th e ne west fu ll mod e l ye ar, a nd a r e exp e ct ed to b e virt u a lly all cle an, t hei r o missi on do es not com p ro mise th e hy b r id eval uati o n altho u g h th e evalu a te d h y bri d effe ctiven e ss may ap pe a r to be le ss g o o d than if all th ese 200 2 mo de ls had be en i n cl ude d. Figur e 4 – V e hicle Ag e Di s t rib u tio n o f Clean S c re en Vehicl es 

### Ag e Di s t ri b u t i o n o f Veh i cl e Sam p les Meeting Cl ean Screen Criteri a

0% 5% 10% 15% 20% 25% 30%198219841986198819901992199419961998200020022004
Model Year% of Candidates Hyb r i d RSD 2 - h i t 5% A u d i t

Figu re 5 sh ows th e p r oj ect e d hyb r id pa ss rate v s . th e cu rrent Cle an S c re en p r og ra m by mod e l ye ar in 200 6. Th e p a s s rate i s hi gh er fo r th e n e west m o d e l s b u t dro p s rapi dly belo w th e cu rre n t prog ram f o r 199 6 a nd old e r mo del s, whi c h were ove r te n yea r s ol d in 200 6. Th e ov erall hy bri d p a s s rate wa s 6 8 % of cand id ate s vs. 78% f o r cu rrent 2
- hit RS D. Figur e 5 – Hy brid v s . Curr en t Cl ean S c r een Pr og ram Pass Rate P a s s R a t e of C l e a n S c r e e n C a n d i d a t e s i n 200 6 an d P r o j e c t e d H y b r i d M e t h o d

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%198219841986198819901992199419961998200020022004
M o d e l Y e a r% Passing Screen R S D 2 - H i t I / M E lig i b le s H y b r i d

z Page 10Tabl e s 3, 4 , 5 an d 6 sh o w t he I M 2 40 t e st re su lts fo r th e ‘Audit Sam p le ’ , ‘Hy b ri d S a m p le’, ‘ O the r RSD 2-hit Sampl e ’, and ‘Audit Sample a n d O t he r R S D 2-H i t Sa mp le C o mbin ed ’. Th e tab l es s how the MY dist ri buti on, th e tail pip e fai l rate, th e ov eral l fail rat e a nd t he ave r a ge I M 24 0 g/ mi e missi on s of ve hicle s pa ssin g the scre e n s
. De spite th e a b sen c e of a fu ll co mpl e m ent of 200 2 m o d e ls, th e av era ge e m i s sio n s of vehi cl es pa ssin g the Hyb r id me thod a r e l o we r tha n th e ‘Au d i t Sam p le ’ by 0.01, 0.1 an d 0.01 g/mi fo r HC, CO an d NOx res pec tively. The ave r a ge emi s sio n s of vehi cle s pa ssi ng th e Hy bri d metho d a r e l o wer t h a n the ‘Othe r RSD 2-hit Sampl e ’ by 0.05, 0. 7 an d 0. 09 g/m i fo r HC, CO a nd NOx re sp e c tively. The Hyb r i d m e tho d i s the r ef ore at le a s t as effec t iv e as the RS D 2-hit method. Tabl e 3 – Au dit Sam p le 200 6 Audi t S a mple V e hicl es Pa ssin g 2 - Hit S c re en w i th RS D CO <0.5 % and HC <2 00 ppm Model Year Fracti on of Screen Passes IM24 0 Tail pip e

Fail Rat e IM Ove r all

Fail Rat e Model Year Vehi cl es IM24 0 Tail pip e Fail ure s Overall Fail ure s IM24 0 Avg. HC g/mi IM24 0 Avg. CO g/mi IM24 0 Avg. NOx g/mi 198 2 0 % 0

. 0 0 % 0

. 0 % 198 2 0 0 0
- - - 198 3 0 % 0

. 0 0 % 0

. 0 % 198 3 0 0 0
- - - 198 4 0 % 0

. 0 0 % 0

. 0 % 198 4 1 0 0 4

. 3 7 2 1

. 2 4

. 2 0 198 5 0 % 0

. 0 0 % 0

. 0 % 198 5 1 0 0 0

. 9 8 1 2

. 9 2

. 0 2 198 6 0 % 0

. 0 0 % 0

. 0 % 198 6 2 0 0 1

. 9 2 1 4

. 7 2

. 8 7 198 7 0 % 0

. 0 0 % 0

. 0 % 198 7 2 0 0 1

. 1 2 8

. 1 1

. 7 2 198 8 1 % 7

. 6 9 % 7

. 7 % 198 8 1 3 1 1 1

. 4 5 1 0

. 7 1

. 8 2 198 9 1 % 0

. 0 0 % 9

. 1 % 198 9 1 1 0 1 0

. 9 3 7

. 8 2

. 1 9 199 0 1 % 4

. 7 6 % 9

. 5 % 199 0 2 1 1 2 1

. 0 4 1 2

. 2 2

. 0 0 199 1 1 % 0

. 0 0 % 0

. 0 % 199 1 1 5 0 0 0

. 7 8 8

. 8 1

. 6 9 199 2 2 % 0

. 0 0 % 0

. 0 % 199 2 2 3 0 0 1

. 0 4 9

. 7 2

. 0 7 199 3 2 % 0

. 0 0 % 2

. 9 % 199 3 3 4 0 1 0

. 7 4 7

. 3 1

. 4 7 199 4 3 % 0

. 0 0 % 0

. 0 % 199 4 5 0 0 0 0

. 5 6 5

. 8 1

. 3 5 199 5 4 % 1

. 5 4 % 7

. 7 % 199 5 6 5 1 5 0

. 6 2 5

. 5 1

. 3 0 199 6 6 % 0

. 0 0 % 2

. 1 % 199 6 9 6 0 2 0

. 3 8 4

. 3 1

. 2 8 199 7 6 % 0

. 0 0 % 1

. 0 % 199 7 9 8 0 1 0

. 3 7 4

. 1 1

. 3 0 199 8 1 2 % 0

. 5 6 % 2

. 2 % 199 8 1 7 8 1 4 0

. 2 9 3

. 6 1

. 0 3 199 9 8 % 0

. 8 4 % 2

. 5 % 199 9 1 1 9 1 3 0

. 3 0 3

. 0 1

. 0 2 200 0 1 7 % 0

. 7 8 % 1

. 9 % 200 0 2 5 8 2 5 0

. 2 0 2

. 8 0

. 6 8 200 1 1 0 % 0

. 0 0 % 2

. 6 % 200 1 1 5 3 0 4 0

. 1 2 2

. 2 0

. 4 8 200 2 2 2 % 0

. 0 0 % 2

. 4 % 200 2 3 3 8 0 8 0

. 1 1 1

. 8 0

. 4 7 200 3 2 % 0

. 0 0 % 0

. 0 % 200 3 3 1 0 0 0

. 1 4 2

. 6 0

. 6 0 200 4 0 % 0

. 0 0 % 0

. 0 % 200 4 0 0 0
- - - 200 5 0 % 0

. 0 0 % 0

. 0 % 200 5 0 0 0
- - - T o t a l 1 0 0 % 0.46 % 2.5 % 1,50 9 7 3 7 0
. 3 1 3
. 6 0
. 9 0

z Page 11Tabl e 4 – H y brid Sampl e Projec ted 2 0 06 H y brid Scr een P a s s e s : RS D CO < 0 .5% & HC < 200ppm, LEI HC/ C O Failure < 2 % Model Year Fracti on of Screen Passes IM24 0 Tail pip e

Fail Rat e IM Ove r all

Fail Rat e Model Year Vehi cl es IM24 0 Tail pip e Fail ure s Overall Fail ure s IM24 0 Avg. HC g/mi IM24 0 Avg. CO g/mi IM24 0 Avg. NOx g/mi 198 2 0 % 0

. 0 0 % 0

. 0 % 198 2 1 0 0 4

. 0 0 3 1

. 8 3.10 198 3 0 % 0

. 0 0 % 0

. 0 % 198 3 0 0 0
- - - 198 4 0 % 6

. 2 5 % 1 8

. 8 % 198 4 1 6 1 3 1

. 7 6 2 0

. 7 2

. 1 4 198 5 0 % 0

. 0 0 % 1 6

. 7 % 198 5 6 0 1 1

. 4 3 1 4

. 8 1

. 9 3 198 6 0 % 0

. 0 0 % 0

. 0 % 198 6 3 8 0 0 0

. 9 9 1 1

. 1 1

. 9 2 198 7 0 % 0

. 0 0 % 1 8

. 2 % 198 7 1 1 0 2 0

. 9 9 1 0

. 2 2

. 1 7 198 8 0 % 0

. 0 0 % 3

. 3 % 198 8 3 0 0 1 0

. 9 5 9

. 4 1

. 5 3 198 9 0 % 0

. 0 0 % 3

. 1 % 198 9 3 2 0 1 0

. 7 9 8

. 4 1

. 6 8 199 0 1 % 0

. 5 6 % 3

. 3 % 199 0 1 8 0 1 6 0

. 8 2 7

. 8 1

. 7 6 199 1 1 % 0

. 0 0 % 4

. 2 % 199 1 2 3 6 0 1 0 0

. 7 6 7

. 7 1

. 7 4 199 2 2 % 0

. 1 6 % 2

. 3 % 199 2 6 0 7 1 1 4 0

. 6 7 7

. 1 1

. 5 3 199 3 2 % 1

. 1 5 % 4

. 3 % 199 3 6 9 7 8 3 0 0

. 7 0 7

. 3 1

. 7 1 199 4 3 % 0

. 9 1 % 3

. 4 % 199 4 9 9 3 9 3 4 0

. 5 6 5

. 9 1

. 3 4 199 5 5 % 0

. 8 4 % 3

. 1 % 199 5 1,42 6 1 2 4 4 0

. 5 1 5

. 1 1

. 3 4 199 6 9 % 0

. 4 6 % 3

. 5 % 199 6 2,82 0 1 3 9 8 0

. 3 8 4

. 2 1

. 1 3 199 7 9 % 0

. 5 1 % 3

. 8 % 199 7 2,94 3 1 5 1 1 3 0

. 3 6 4

. 1 1

. 1 1 199 8 1 6 % 0

. 2 9 % 2

. 0 % 199 8 5,21 4 1 5 1 0 3 0

. 3 0 3

. 4 0

. 9 1 199 9 1 2 % 0

. 2 1 % 2

. 3 % 199 9 3,78 1 8 8 7 0

. 2 7 3

. 0 0

. 8 6 200 0 2 4 % 0

. 2 3 % 2

. 3 % 200 0 7,53 8 1 7 1 7 0 0

. 2 0 2

. 5 0

. 6 6 200 1 8 % 0

. 1 7 % 2

. 2 % 200 1 2,38 7 4 5 2 0

. 1 4 2

. 1 0

. 4 8 200 2 5 % 0

. 2 5 % 2

. 3 % 200 2 1,60 1 4 3 7 0

. 1 2 2

. 0 0

. 4 4 200 3 2 % 0

. 0 0 % 1

. 2 % 200 3 7 5 3 0 9 0

. 0 9 1

. 7 0

. 3 6 200 4 1 % 0

. 0 0 % 1

. 2 % 200 4 3 2 6 0 4 0

. 0 8 1

. 5 0

. 2 9 200 5 0 % 0

. 0 0 % 0

. 0 % 200 5 8 0 0 0

. 0 7 1

. 3 0

. 2 8 T o t a l 1 0 0 % 0.34 % 2.6 % 31,6 4 4 1 0 8 8 1 9 0
. 3 0 3
. 5 0
. 8 9

z Page 12Tabl e 5 – Oth e r RS D 2-Hi t Sample Other V e hicl e s Pas s ing 2-h i t Scr e e n w i th CO <0.5 % a nd HC < 2 00ppm Model Year Fracti on of Screen Passes IM24 0 Tail pip e

Fail Rat e IM Ove r all

Fail Rat e Model Year Vehi cl es IM24 0 Tail pip e Fail ure s Overall Fail ure s IM24 0 Avg. HC g/mi IM24 0 Avg. CO g/mi IM24 0 Avg. NOx g/mi 198 2 0 % 0

. 0 0 % 0

. 0 % 198 2 4 0 0 1

. 9 6 1 5

. 6 3.15 198 3 0 % 0

. 0 0 % 0

. 0 % 198 3 2 0 0 1

. 5 8 1 1

. 5 4

. 1 5 198 4 0 % 0

. 0 0 % 7

. 1 % 198 4 1 4 0 1 1

. 8 8 2 1

. 2 2

. 4 6 198 5 0 % 4

. 3 5 % 4

. 3 % 198 5 2 3 1 1 1

. 1 5 1 4

. 1 2

. 3 3 198 6 0 % 2

. 2 2 % 4

. 4 % 198 6 4 5 1 2 1

. 3 0 1 3

. 9 2

. 2 8 198 7 0 % 5

. 4 5 % 9

. 1 % 198 7 5 5 3 5 1

. 1 3 1 1

. 9 2

. 3 3 198 8 1 % 1

. 7 1 % 4

. 3 % 198 8 1 1 7 2 5 1

. 1 3 1 1

. 9 1

. 9 5 198 9 1 % 2

. 7 0 % 5

. 4 % 198 9 1 1 1 3 6 1

. 0 4 1 1

. 6 1

. 9 4 199 0 2 % 0

. 8 7 % 6

. 1 % 199 0 2 3 0 2 1 4 0

. 8 9 8

. 7 1

. 7 9 199 1 2 % 1

. 9 6 % 7

. 5 % 199 1 2 5 5 5 1 9 0

. 8 4 8

. 8 1

. 8 3 199 2 3 % 3

. 4 2 % 7

. 8 % 199 2 4 0 9 1 4 3 2 0

. 8 2 9

. 4 1

. 7 2 199 3 3 % 1

. 6 1 % 4

. 6 % 199 3 4 3 6 7 2 0 0

. 7 3 7

. 9 1

. 8 6 199 4 4 % 1

. 5 3 % 4

. 1 % 199 4 5 8 9 9 2 4 0

. 7 0 7

. 4 1

. 5 9 199 5 5 % 2

. 0 8 % 5

. 6 % 199 5 8 1 8 1 7 4 6 0

. 6 3 6

. 2 1

. 4 5 199 6 8 % 0

. 5 1 % 2

. 1 % 199 6 1,16 7 6 2 5 0

. 4 1 4

. 7 1

. 2 6 199 7 8 % 0

. 8 9 % 3

. 7 % 199 7 1,23 7 1 1 4 6 0

. 4 0 4

. 4 1

. 1 7 199 8 1 3 % 0

. 6 3 % 2

. 3 % 199 8 2,05 4 1 3 4 8 0

. 3 1 3

. 9 0

. 9 7 199 9 1 0 % 0

. 0 6 % 2

. 0 % 199 9 1,57 8 1 3 2 0

. 2 7 3

. 2 0

. 8 8 200 0 2 0 % 0

. 2 0 % 2

. 2 % 200 0 3,03 7 6 6 7 0

. 2 0 2

. 7 0

. 6 6 200 1 7 % 0

. 0 0 % 2

. 3 % 200 1 1,14 2 0 2 6 0

. 1 3 2

. 2 0

. 5 0 200 2 5 % 0

. 0 0 % 1

. 6 % 200 2 7 7 0 0 1 2 0

. 1 1 1

. 8 0

. 4 3 200 3 5 % 0

. 0 0 % 1

. 3 % 200 3 7 7 5 0 1 0 0

. 0 9 1

. 6 0

. 3 6 200 4 3 % 0

. 0 0 % 0

. 5 % 200 4 4 2 0 0 2 0

. 0 8 1

. 5 0

. 2 9 200 5 0 % 0

. 0 0 % 0

. 0 % 200 5 1 1 0 0 0

. 0 7 1

. 6 0

. 1 9 T o t a l 1 0 0 % 0.66 % 2.9 % 15,2 9 9 1 0 1 4 4 3 0
. 3 5 4
. 2 0
. 9 8

z Page 13Tabl e 6 - Au dit Sampl e a nd Othe r RS D 2
- Hit Sam p l e Co mbin ed 200 6 Audi t S a m p le + O t h e r 2- Hi t Pas s in g 2- Hi t Scr e e n w i t h RS D C O < 0 .5% and H C < 2 2 0 ppm Model Year Fracti on of Screen Passes IM24 0 Tail pip e

Fail Rat e IM Ove r all

Fail Rat e Model Year Vehi cl es IM24 0 Tail pip e Fail ure s Overall Fail ure s IM24 0 Avg. HC g/mi IM24 0 Avg. CO g/mi IM24 0 Avg. NOx g/mi 198 2 0 % 198 2 4
- - 1

. 9 6 15.6 1 3.15 198 3 0 % 198 3 2
- - 1

. 5 8 11.5 3 4

. 1 5 198 4 0 % 0

. 0 0 % 6

. 7 % 198 4 1 5
- 1 2

. 0 5 21.2 3 2

. 5 8 198 5 0 % 4

. 1 7 % 4

. 2 % 198 5 2 4 1 1 1

. 1 5 14.0 4 2

. 3 1 198 6 0 % 2

. 1 3 % 4

. 3 % 198 6 4 7 1 2 1

. 3 3 13.9 6 2

. 3 0 198 7 0 % 5

. 2 6 % 8

. 8 % 198 7 5 7 3 5 1

. 1 3 11.7 7 2

. 3 1 198 8 1 % 2

. 3 1 % 4

. 6 % 198 8 1 3 0 3 6 1

. 1 7 11.8 0 1

. 9 4 198 9 1 % 2

. 4 6 % 5

. 7 % 198 9 1 2 2 3 7 1

. 0 3 11.2 7 1

. 9 6 199 0 1 % 1

. 2 0 % 6

. 4 % 199 0 2 5 1 3 1 6 0

. 9 1 9

. 0 0 1

. 8 1 199 1 1 % 1

. 8 5 % 7

. 0 % 199 1 2 7 0 5 1 9 0

. 8 4 8

. 8 3 1

. 8 2 199 2 3 % 3

. 2 4 % 7

. 4 % 199 2 4 3 2 1 4 3 2 0

. 8 4 9

. 4 3 1

. 7 4 199 3 3 % 1

. 4 9 % 4

. 5 % 199 3 4 7 0 7 2 1 0

. 7 3 7

. 8 9 1

. 8 3 199 4 4 % 1

. 4 1 % 3

. 8 % 199 4 6 3 9 9 2 4 0

. 6 9 7

. 2 8 1

. 5 7 199 5 5 % 2

. 0 4 % 5

. 8 % 199 5 8 8 3 1 8 5 1 0

. 6 3 6

. 1 9 1

. 4 4 199 6 8 % 0

. 4 8 % 2

. 1 % 199 6 1,26 3 6 2 7 0

. 4 1 4

. 7 1 1

. 2 7 199 7 8 % 0

. 8 2 % 3

. 5 % 199 7 1,33 5 1 1 4 7 0

. 3 9 4

. 4 0 1

. 1 8 199 8 1 3 % 0

. 6 3 % 2

. 3 % 199 8 2,23 2 1 4 5 2 0

. 3 1 3

. 8 6 0

. 9 7 199 9 1 0 % 0

. 1 2 % 2

. 1 % 199 9 1,69 7 2 3 5 0

. 2 7 3

. 1 6 0

. 8 9 200 0 2 0 % 0

. 2 4 % 2

. 2 % 200 0 3,29 5 8 7 2 0

. 2 0 2

. 6 9 0

. 6 7 200 1 8 % 0

. 0 0 % 2

. 3 % 200 1 1,29 5
- 3 0 0

. 1 3 2

. 1 5 0

. 5 0 200 2 7 % 0

. 0 0 % 1

. 8 % 200 2 1,10 8
- 2 0 0

. 1 1 1

. 8 2 0

. 4 4 200 3 5 % 0

. 0 0 % 1

. 2 % 200 3 8 0 6
- 1 0 0

. 0 9 1

. 6 7 0

. 3 7 200 4 2 % 200 4 4 2 0
- 2 0

. 0 8 1

. 5 1 0

. 2 9 200 5 0 % 200 5 1 1
- - 0

. 0 7 1

. 5 8 0

. 1 9 T o t a l 1 0 0 % 0.64 % 2.9 % 16,8 0 8 1 0 8 4 8 0 0
. 3 5 4
. 1 0
. 9 7

z Page 14