Document 4j7G7JBDNqNMmjRLZBeayYN

fSHPPP *mm LIA15486 Stmit -^nr irtnyin r* x Lead Industries Association, Inc. nt MM. MW Mw Ym% H. V. W1T TMpMw (TO HHM ..iimM. nil saMaBMsaeidiiaBMia^^ June 3, lf7J mJBCTi d o p o w t reowiog iw a c a j to na omctu nmua or m HAD XXOUSTXUS ASSOCIATION, jaC.1 Attached la copy of a paper recently presented to a body of the American fttroleia Institute by Du font personnel which. In considerable technical detail, explains the feasibility of the thermal reactor and trap device which would permit the continued use of loaded gasoline. The peper presents facta and figures on emission controls, and relates the penalties in foal consuaptioo resulting from tbsau We feel thia could be valuable information for company personnel *d axe asked questions about the lead In gaeolina situation, the fuel shortage and tha validity of tha reactor-trap concept. There ere a limited number at additional copies available. Sincerely, Hip l. hoblnscn Ksecutlve Vice President Pnt/JFS/la tary t General Manager ha*--inI. mmmm mm BPPUPipnHMJ i^eee sue -i f l ' i i ^ ...^.j^,.... , usSyjiiiife LIA15A87 BmOArn. Prrprim Nm. !f7$--IA>h I tmCmrrrrd^rn RELEASE AFTERNOON PAPCM TUESDAY, MAY If M hr rmrnml,m at a Sndmm mm tmdiAm C--mmt tymrnu mmd fmrt <nriii ml W5 H Cmn, II. Dmm9* Ifc f*th MiAtrmi Hrrt,m, ml ikr Amrrmmm Hmrnlrmm I utofi Dnymmm ml lituti, m Am Brmtmrnmm frmmtlmi B--rl, r*fr Mf*mm. tm, Mmy It. 1911. A TOTAL VLHK3X EMISSION CONTROL SYSTEM E. N. Cwiiu,* W. E. Bimwit,' a k o S. M. hiutn* :?3 1 j Hi I.* m *E. I *i famt 4t himmmntCa . Ik ,WWml Od * Y m N 3538.01 mm mm illtftilMi'i i'i i mm mm LIA15488 itf&iia jWWW! p p p iiw TABLE OF CONTENTS ABSTRACT INTRODUCTION AIR OUAUTT AVn EMISSION STANDARDS Rollback Analysis Aaaljrili of Air Quality Trsods Alternate Automotive Emleatan Standards EFFECT OF EMISSION CONTROLS ON FUEL CONSUMPTION Teat Fleet and Procedures Performance and Fuel Consumption of 1970 to 1973 Oars Comparison of Du Poet and EPA Data Estimated Fuel Consumption Losses From Pre-1966 Through 1976 Models TOTAL EMISSION CONTROL SYSTEMS Design of TECS m Emission Control With TECS HI Fuel Consumption and VoMcls Performance Performance of Lead Traps CONCLUSIONS ACKNOWLEDGMENTS REFERENCES 1 15 11 16 IS tl a u 19 SO St IS a so Tarnmmmmmmsx rmmm* mtmmm mmmm# mm mm mm mmmmmmmm LIa 154 gg ABSTRACT Studies of ambient air quality level* from the CAMP station*, traffic flow In urban central business districts, and emission rata* from vehicles oo the road suggest thst the automotive exhaust emission standards mandated by the Clean Air Act Amendments of 1970 may be more stringent than required to attain the national ambient air quality standards. Based on preliminary results from continuing studies, emission levels as measured by the 1975 Federal Test Procedure of IS to 40 grams per mile of carbon monoxide, 0.4 to 0,0 gram per mile of hydrocarbons, and 1.5 to 3.0 grams per mile of nitrogen oxide* appear to be adequate. The application of emission control systems to date and tbs reduction of compression ratios have increased the fuel consumed by an average weight domestic sedan by 17 percent compared with preeml sal an control vehicles. This consumption penalty la predicted to double if the emission control systems now contemplated are used to meet the current 1976 standards. If vehicle emission standards were changed to the value* suggested above as being adequate to attain ambient sir quality stan dards, noocatalytlc exhaust emission control systems based on thermal reactors, exhaust gas recirculation, and engine modifications could be employed. Such system* would permit the continued use of high octane leaded gasoline giving motorist* the opportunity to us* the lowest cost fuel In high compression, more efficient engines. The fuel consumption of cars using such control systems Is leas than 8 percent greater than corresponding 1970 production vehicles or approximately equivalent to the current 1973 production car*. mmm mmrnmrn riirihi LIA15A90 ..... .. ..... . ..- ----------- --- A TOTAL VEHICLE EMISSION CONTROL SYSTEM E. N. Cantwell, W. E. Bettooey, 3. M. Flamed INTRODUCTION Prior to 1970, control of automotive emissions flrat by the State of California and later by the U.S. fovernment was based on the application of demonstrated technology. Future emission goals were based on the expected rate of development of improved technology to reduce emlaalona. However, with the passage of the Clean Air Act Amendmenta of 1970, Congress mandated (l)*by 1975, emissions of hydro carbons and carbon monoxide must be reduced by 90 percent from (he 1970 levels and (2) by 1976, emissions of nitrogen oxides must be reduced by 90 percent. Congress was concerned that public health and welfare might be affected by pollution caused by automobiles and thus felt that drastic action eras necessary. The Clean Air Act of 1970 also directed the ll.S. Environmental Protection Agency to determine national ambient air quality standards which would protect public health and welfare. Because emission levels were mandated first and air quality standards established later It la not unreasonable to expect that the degree of emission control legislated by Congress might not be consistent with what was needed to achieve national ambient air quality standards later promulgated by the EPA. Since die 1970 Clean Air Act Amendments were passed, additional data have been generated which are useful In assessing the adequacy of the emission reductions mandated by Congress. The need for carefully setting the automotive emissions standards arises from the fact that for most types of automotive engines fuel consumption Increases with the degree of control which la Imposed. Thus, the degree of emission control and the extent of the fuel consump tion penalty must be considered at the same time. In view of the critical crude otl supply situation In this country, U Is Imperative that a balance be struck between the desirability of achieving ultra-low emission levels for automobiles and the desirability of minimising fuel consumption penalUss. The purpose of this paper la to report on the progress being made In major programs being carried out by Du Pont in these areas of concern. The results of studies to date show that: Achievement of national air quality standards may be possible with automotive emission levels of hydrocarbons, carbon monoxide and oxides of nitrogen less stringent than mandated by Congress in the 1970 Clean Air Act Amendments. Noncatalytlc total emission control systems hava been developed which are capable of redurli^ automobile emissions to levels which should permit achievement of the national ambient air quality standards without suffering large fuel penalties. Numbers In parentheses refer to references on page* 96 and 9T. PURMPPM*-! PS!1 mm idmi i ' : " i ~ MtxiatlaaTHai iiiiM>ni*Mir < i am tsirTirm trrnrri riirJ- - LIA15491 -- In general, fuel consumption penalties of vehicles equipped with emission control systems are dependent on the degree of emission control. This penalty probably will vary with the type of emission control system which Is used and with the relative amounts of control of hydrocarbons, carbon monoxide and nitrogen oxides. Vehicles meeting standards that will permit achievement of the ambient air quality standards are projected to have a much lower fuel consumption penalty than vehicles equipped to meet the 1976 emission standards mandated by the Clean Air Act Amendments of 1970. AIR QUALITY AND EMISSION STANDARDS The EPA published ambient air quality standards for six major atmospheric pollutants In 1971 (1). The standards for hydrocarbons, carbon monoxide, oxidants, and nitrogen dioxide associated with automotive usage are shown In Table 1. The adequacy of these national air quality standards has been vigorously debated. Some critics contend that some of these standards are too high to adequately protect the public health while others contend that they are lower than can be supported based on medical evidence. Still others point out that some of the standards approach or are below natural background levels and thus are extremely difficult or perhaps Impossible to attain. For the purposes of this paper, the goal of meeting the ambient air quality standards will be accepted and only the question of what automotive emissioe standards are needed to meet these standards will be examined. TABLE I NATIONAL AMBIENT AIK QUALITY STANDARDS FOH AUTOMOTIVE POLLUTANTS Carbon Monoxide Hydrocarbons Nitrogen Oxides Oxidant 9 ppm 35 ppm 6-Hour Average* 1-Hour Average* 0.24 ppm C; (6-9 a. m.) 3-Hour Average* 0.05 ppm NOg Annual Arithmetic Mi 0.06 ppm 1-Hour Average* * Not to be exoeeded more than onos a year 4 m 1 i i i i i i M k m w tta s n .s .a .s n e s ian.nn.,4.1 .n-- h i etsigfitiHMtfaiaa |H < 1*1111 ..................... . m s S liiiilM iilllllM ^ mm9 rnmmmmm L IA15492 ***** Rollback Analysis A crucial atop 1b air resource management la to decide what etniaeioea reduettona are seeded to meet air quality goals. To do this, knowledge of the relationship between pollutant emissions and ambient air quality la needed. Although there has been considerable effort directed to the development of mathematical models for prediction purposes the practical decisions on needed emissions reductions have been made in the part on the basis of the so-called "rollback" approach first used by California and later by EPA. This approach assumes that the pollutant concentration is proportional to the emission rata of the pollutant. The equation Is: where: R _ (CP) (PAQ) - (DAQ) <GF) (PAQ) - (B) R - Fractional emission rata reduction required to achieve desired air quality GF - Emission Growth Factor PAQ Present Air Quality DAQ Desired Air Quality B Background Air Quality To Illustrate, achievement of the national ambient air quality standard for carbon monoxide requires that the 6-hour average carbon monoxide concentration not exceed 9 parts per million (ppm) more than once par year. (Carbon moocodde is chosen as an example because In many large cities most of it can be ascribed to vehicular activity.) Then, by the reasoning of the rollback approach. If the 6-hour average carbon monoxide concentration exceeded once per year la 18 ppm, a reduction of emissions to half the current rate is expected to achieve the 9 ppm air quality standard level, assuming background to be negligible. The Federal and State agencies have used the rollback approach to calculate the automotive emission standards required for achievement of ambient air quality standards for various combinations at assumed implementation dates and sir quality standards. These calculations usually are made to estimate the emission reduction required to meet the air quality standard In the most polluted location, usually the central business district, at some future date. This degree of control is expected to guarantee achievement In less polluted places In the agency jurisdiction. The amount of growth expected In emission sources hat significant effect on the reduction required in vehicle emission levels. As an example, EPA has calculated the degree of emission reduction required to achieve the ambient air quality standards for CO for the city of Chicago for two different time periods (2,3). The first EPA calculation. Table 2, assumed that implementation of stringent emission standards would occur In 1980 while the second calculation assumed 1972. In both cases a vehicle growth rate of approximately 2.4 percent per year was. assumed for the city of Chicago. Vehicle traffic in the central business district has been essentially constant for the past tan years based on data obtained from the city of Chicago, and shown in Figure 1. Thus, the use of a national or even a r u mp * mm trnatm \ rnrnmmimmm imna i^MMf^'^'"- wmmmmm LIA15493 TABLE ALTERNATIVE CO EM IBSON STANDARD* COMPUTED BY ROLLBACK MODEL CITY OF CHICAOO Worrt-Caae Ambient CO, ppm(oocurred December, IMS) Ymt of ImplwnattUo* of Emiaaian Standard Erniealoe Growth Factor Background Air Quality, ppm Deaired Air Quality, Ppm Emleaioo Reduction Required, l Baaed on Pro-IMS Vehiclea Emiaaioc Standard, g/KiW (CVS-7S) Future Worat-Caae Ambient CO, ppm EPA 1M. ?) EPA fiaLJb 4* 44 1M0 til 1 t 197* LM I tt 99 C.S 9.9 9 Year Achieved 1M0 IMS Ftf 1 - Dafty Cotton Traffic Cwiti tor to Central Bumntm Dtetrier f Otimpt. J ... . >.,> *pil WipjiJBIJUIHyn ijPMilii ' mim regional vehicle growth rate may not be appropriate for the central business district in a major urban area. Tbl* condition of traffic saturation apparently exist! tn moat major urban areas which are the regions of moot concern since they have the highest levels of automotive derived air pollution. Rollback calculations to determine needed automotive emission levels to meet the air quality standards are very dependent upon valuee used for vehicular growth factors and ambient air quality standards as illustrated In Table 3. With 1975 as the Implementation data for stringent emlssloo control, the allowable emissions of carbon monoxide range from 9 to IS grams per mile and the hydrocarbons from 0.32 to O.i gram per mile depending on the value of the growth factor assumed. The threefold difference in allowable NO* emissions between the first and second EPA calculations results from using different ambient air quality standards. The ambient air quality standards used tn the first calculation was an NOj level of 0.1 ppm average for one hour not to be exceeded more than once per year. This standard, when applied la Loe Angeles results In an allowable NO* emission standard of 0.36 gram per mile. The second calculation was based on a national ambient air quality standard issued by EPA of 0.05 ppm NOj an an annual average basis. This standard, when applied ta New York City resulted In sn allowable emission standard for NO* of 1.2 grama per mile. With the growth factor equal to unity the allowable emission rate of NO* rises to 1.6 grams per mile. Also shown are the proposed California standards for 197S vehicles which are predicated on the achievement of California air quality standards (4). Allowable emission standards required to meet the ambient air quality etas* dards when calculated using the rollback method are quite sensitive to assumed lap* values and tn view of the economic Impact of even small differences In these emission standards, a better method la needed. TABLE 2 Source EPA EPA Du Pont California ROLLBACK MODEL IS SENSTITVE TO ASSUMED INPUT VALUES Year of Implementation 1980 197S 197S 197S Growth Factor 2.18 1.54 1.00 Allowable Emissions To Meet Air Quality Standards Grama Per Mile* CO _H_ NO, e.s 0.15 0.26 9.2 0.22 1.2 15.0 0.5 1.5 17.2 0.5 1.5 * 1975 CVS Test Procedure f IPmxrnmmmmmm'n juiiipiii.jipgiswRnppmF' i l......... H i P W ....... 'I I ...."l l W Mi l UP MTi'sniiifMiW mm i,iP'fmirt#ii ipp .............. LIA15495 Analysis of Air Quality Trends An alternative method of determining required emillion reduction! li to analyze the response of ambient air quality to the downward changes In vehicular emission rates which hsve taken plaoe slnoe emission control was instituted la California In 1966 and nationwide in 1968. This approach does not depend upon the development of adequate mathematical diffusion models and Inherently accounts for the influence of atmospheric processes on the relationship between emissions and air quality. It also Incorporates any growth that did take place and does not require the simplifying assumptions needed for the rollback analysis. Trend analysis of air quality la now possible because almost onerhalf of the cars on the streets are now equipped with tome type of emission control system and the Impact of the emission control should be readily apparent. Such wae not the oeee In 1969-70, and as a result the only technique arailable for calculating required automotive emission reduction was the rollback method. A considerable body of air quality data is available for trend analysis. The first source is from tha Continuous Air Monitoring Project (CAMP) being conducted by EPA (5). The second source is the air monitoring data gathered by the State of California Department of Public Health. We are In the prooeas of an extensive analysis of the air quality data which have been made available to ua on magnetic tape by EPA and the State of California. Because carbon moooxlde in urban areas la primarily associated with vehicular traffic and because this pollutant, at least on a abort term basis la conserved, we have concentrated our initial studies on it. A more detailed and complete description of this analysis may be found in the forthcoming paper to be presented at the June 1973 meeting of the Air Pollution Control Association (6). Thii work la continuing and In addition we also hare Initiated analyses of ambient air quality data for hydro carbons, nitrogen oxides, and oxidants to examine the relationships for these I pollutants. There has been a general Improving trend In carbon monoxide air quality over the years at the six CAMP sampling sites near the centers oI the cities listed as shown In Tables 4 and 5. Annual average CO values, as well as the percent of the time that the ambient air quality standard levels were exceeded, have decreased i In all of the cities. The only exception to this decrease occurred in Denver during 1970 and 1971. We are examining the situation in Denver to explain this Inconsis tency. A detailed study has been made for Chicago, the city cited by EPA as having the worst vehicular carbon monoxide problem, and the prototype case used la the EPA rollback calculations of required nationwide carbon monoxide emission rate reductions (2,3). To date, three fedora have been examined In some detail: the trend of vehicle CO emissions, tha trend of motor vehicle use In the area surround ing the CAMP air sampling location, and the trend In maximum ambient CO levels. The trend In CO emission rate for the vehicle population on tha road has steadily downward over recent years In response to reductions concurrent with I UA15496 . rims^d--rai-riW*- ' 3 - J TABLE 4 CAMP CARBON MONOXIDE TRENDS Annual Average CO Concentration, oom Year Chi caro Denver Washington Cincinnati St. Louis Philadelphia ltd 1963 1964 1963 1966 1967 1968 1969 1970 1971 12.1 17.1 12. S 6.2 8.2 5.4 7.3 8.4 4.6 6.7 5.3 6.9 5.T 3.T 3.4 3.0 3.3 7.1 6.1 6.4 4.9 6.8 8.7 4.6 - 8.1 4.4 2.3 4.4 7.2 9.1 6.4 9.7 3.9 4.1 2.6 i TABLE 5 i * CAMP CARBON MONOXIDE TRENDS Percent of Time the 8-Hour Federal CO Standard (9 ppm! Wat Exceeded Year Chicago Denver Washington Cincinnati St. Louis Philadelphia 1962 1963 1964 1965 19S6 1967 1968 1969 1970 1971 21 37 67 92 71 40 18 38 24 14 36 34 30 U 5 IS 19 11 20 3 2 2 8 2 0 2 2 29 29 16 2 21 3 12 S7 S2 1 9 9 11 23 35 19 19 39 1 2 1 i * m L IA 154 97 ignm Introduction of new model year vehicle*. Thle trend bated on EPA date (3) ta shown In FIjure I. Cara were flrat required to meet national CO emlaalon atandarda In 1968. Decreaaea in CO emlaalon rate In earlier model yeara can be aacribed to engine modification! made In anticipation of tbe Impoeitloe of emlaatoo atandarda. Tba lag between the atep reduction of CO emlaalon rate from one model year to the next, and tbe decreate In tbe average CO emlaalon rate for vehiclea in ate refleote tba fact that only about 10 percent of tbe vehicle population ta replaced each yeer. Aa we have already abown In Figure 1, the traffic In tbe area aurroundlng the EPA Chicago CAMP air aampling etatioo baa been approximately tbe aame over the laat decade. Thua, tbe changea In ambient air quality abould be proportional to the changea In emlaaloa ratet. Maximum 8-hour average CO level a reached each month in Chicago have bean decreaelng to about tbe aame degree aa vehicular CO emlaalone aa abown In Figure 3. If tbe trend envelope ettabllehed by tbe monthly maximum CO occurrence! In the 1965-71 period, abown by tba dashed line In Figure 3, la extended. It would Indicate tbe 9 ppm air quality etandard level abould be achieved In 1974. Aa tbe air qualify etandard allowe thle level to be exceeded once per year, achievement of tbe level la more atrlngent than required. At tbe pro)ected time of achievement of tbe 9 ppm level. In mld-1974, the vehicle population CO emlaalon rate aa Indicated by tbe vehicle emlaalon curve will be approximately 40 grama per mile. Obvloualy, the trend line drawn through tbe peak CO occurrence la drawn on tba bada of limited Input data but considering tbe remaining data. It appears reasonable. Alternate Automotive Emruion Standard* In view of disagreement among tbe emission standards calculated by tbe various rollback techniques and implied by tbe analysis of historical air quality trends, further reexamination of tbe national vehicle emisaloe standards would appear warranted. Although much work remains to be done In this area. It la possible to suggest a range of automotive emission standards which apparently would meet ambi ent air quality standards aa highlighted In Table *. The rollback analysis applied to Chicago euggesta that carbon monoxide levels between 9 and IS grama per mile would be appropriate, whereas tbe analysis of the air quality trends for Chicago suggests a CO value of 40 grama per mile. Certainly tbe value of 15 grams per mile for CO ae derived by tbe rollback method la a conserva tive level. In the case of hydrocarbon levels tbe rollback equation suggests 0.3 U> 0- S gram per mile. In tbe absence of conclusive analysis of tba relationships between tbe trends of ambient oxidant levels and exhaust hydrocarbon emission levels il would seem appropriate to retain a hydrocarbon emlaalon standard at tbe average value of 0.4 gram per mile. On tbe other hand. If tba two- to threefold differences between CO valuea calculated by rollback analysis and air quality trend analysla also applies to hydrocarbons, then a hydrocarbon standard of at least two times greater or 0.1 gram per mile would be appropriate. WP PPfPP V LIA15A98 We 2 - CvkM Mmu Mi Emimn Ram af LiyM Owtv hwnfK Can by Modal Veer and Avaraga Carbon Manaaida Enaaoi Horn ter Ad daw Viiadn on da Hand In lad J Mandhf Maalnun Ambient Cataa ManaaMa Coneemetieni Iron dm CAMP Malian la i fa TABLE ALTERNATE AUTOMOTIVE EMISSION STANDARDS* ** Uvl M>ded to Atula Air Quality fluadudi Rollback Air Quality Trend Analysis 1973-74 1975 Nationwide (7) 1975 California (7) 1979 Emltaloo Levels, Grams Par MUa 1975 CVS Tet Procedure_____ -2- -H_ *2 IS 40 28 15 9 S.4 0.4 .$ 2 l.S 0.9 0.41 1.5 2 to 3.0 3.1 2.0 0.4 * Rollback valua adjusted for oatlmatad differences between rollback and air quality trend analyses observed with carbon moooxide. ** Rollback value adjusted for anticipated upward revision due to errors In measurement of ambient NOf levels. II w pp mmmmtmmmwmmmm m i mii j * nMsIn. rniawrsradasafawnMi>* In the cue of nitrogen coddee, the rollbeck equation suggests nitrogen cndde emission atandarda ranging between 1.2 and 1. 8 grama per mile or an average of 1.8 gram* per mile. However, the EPA hae ataled that the ambient levela of NO] were meuured Incorrectly becauie of faulty analytical technlquea and that they will suggest to the Congreaa that the emlaaion atandard ahould be revlaed upward (7). If euch an upward revision were to take place, the allowable automotive emission atandard would lncre&ae from 1. S to a value of perhape 2 to 3 grama per mile. TUa alao would appear reasonable In light of the experience with OO. When the levela of automotive emlaaion atandarda needed to achieve ambient air quality atandarda are compared with the current automotive emlaaion atandarda abown in Table 6 It can be aeen that they correspond moat closely to the 1875 Interim atandarda for the 6Late of California recently announced (7). The hydrocarbon and nitrogen oxides atandarda are In excellent agreement while the 1*75 California atandard for carbon monoxide may be lower than needed. EFFECT OF EMISSION CONTROLS ON FUEL CONSUMPTION In the absence of any other considerations It would be desirable to attain the lowest emission levels from automobiles that are technologically achievable. However, available Information Indicates that fuel consumption Increases with Increasing strin gency of emission control. Preservation of our natural resources such u ends nil la very Important so It la Imperative to achieve a balance between gasoline utlliiatlae and the degree of air quality achieved. Therefore, the goal should be to set automotive emiaaloo standards at those levela which will just scMere the ambient air quality standards In the worst urban areas since this approach will minimise gasoline consumption. To assess the fuel consumption penalty of achieving low, and perhaps unnecessarily stringent, emlaaion levels in the future it la necessary to quantify the effect of emiaaloo control systems already Installed on rehides and predict wbat the penalties will be when more stringent emission control systems are used. Two studies on the effect of emission control systems on vehicle fuel consumption have been used. First, trends in fuel consumption and performance of car models pro duced since the 1970 model year have been determined at Du Pont. Second, a report detailing the fuel economy of more than 2,000 vehicles spanning the model year* from 1957 to 1973 has recently been released by EPA (8). Data from tbaaa two studies are examined In this section and are used as a basis to assess the penalties which have occurred and to project anticipated fuel consumption penalties through tbs year 1976. T*t Fleet and Procedures The Du Pont Petroleum Laboratory baa purchased a fleet of representative, current model cars each year for the past 20 years to determine tbs road octant quality of fuels and the octane requirements of cars. Since 1970, we have purchased each year a group of six cars of the same make and model, and equipped with the same accessories. We have determined fuel consumption and acceleration performance for these cars each year after they have been operated at luit 5,000 miles. Information on the Individual ears la summarized la Table T. ^ If -Pn-wpn '.i jwiip wmm I i r t 5 I P H 1 t r i f r LIA15500 m* Prom 1970 to It71 the oompreaeioci ratio of moot engine# decreased elgnifl-............. cantly with aomo additional reduction In the average for all oara tor 1972 and 197S model*. Aa ahown In Table 8, the average compression ratio declined 0.9 unit from 1970 to 1971 and 0.1 additional unit In both 1972 and 1973. Average* for the eU care were within 0.1 ratio of weighted U. 8. average car based on studies of Coordinatlrg Research Council Octane Number Requirement Surveya for 1970, 1971, and 1978 (9,10,11). TABLE T CARS USED IN FUEL ECONOMY PROGRAlf V-8 Automatic Tranami aalooa 1970 to 1973 Models Car Male* A C O E F G Air Condi tlonlns Yee Yes Yes Yes No No Displacement C1D 950 455 400 SSI 902 919 Carburets* Barrel* 9 4 1 9 1 9 1 M 0 * TABLE c o mp r e s s io n r a t io or CARS u s e d in p r o g r a m Manufacturer's Published Ratios Car Make __________ Model Year 1222 1971 1972 1222 A C D I F O Average 9.0 10.0 10.0 9.9 9. S 8.9 9.9 8.8 9.8 8.2 9.0 9.0 JJ 8.8 8.8 8.9 8.9 8.8 JL2 I.S I.S 8.0 8.9 4.0 -Li Weighted CRC Average* 9.4 t.T 9.9 Baeed on analyele of data In CRC Octane Number Requirement Surveya for 1970, 1971, and 1971. p PWI'WPI p'UmWMMPPP 19 Tinitfn' iaf itfiftirriSMaitf The weight ofthe vehicles Increased each nodal year with the average In creasing 291 pounds from 1970 to 1973 as shows Is Table 9. About half of tide Increase (14 6 pounds) occurred between the 1972 and 1973 models and Is associated primarily with safety standards Involving bumpers. A change In construction of Make F from unit body to frame and body oolncided with an Increase of 610 pounds for that car from 1971 to 1972, There were no significant changes lu rear axle ratios, tire sixes, or automatic transmission characteristics. Changes affecting carburet!on. Ignition timing, valve timing, and exhaust gas recirculation were made to the vehicles throughout the period to meet the successively more stringent U. B. vehicle emission standards. Performance was measured In terms of time, in seconds, to eocelerate from 25 to 60 mile* per hour and 0 to 60 miles per hour. Speed and Urns were plotted eutomatlcally from e speed sensor on a fifth wheel. Six repeat accelerations were run. three In each direction, on a straight and level section of e public highway. Result# are based on the average of the times In seconds for the six accelerations. Fuel consumption was measured by driving over a 26 mile urben-sdburhen oourae which Included approximately nine miles of dty traffic and 17 miles of sub urban and interstate highways. A summary of the test course la outlined In Table IS. More time wee spent In dty traffic than on the highway. The test vehicles were fueled from auxiliary tanks located in the trunk and the fuel consumed was determined bf weight difference. The vehicles were tested In matched pairs so that they drove the oourae la an Identical time to Insure that variations in traffic sad thus variations In average speed on the course did not unduly Influence the results. The drivers end the position of the cars were rotated and replicate teste of at least four determinations on each matched pair were made. Due to changes In traffic lights in the dty portion of the test course the average speed has decreased from s value of 28.6 mph in 1970 to a current average value of 24.4 mph. Thus, it was not possible to compere data obtained several years ago with current data because the. fuel consumption was effected by speed. A minor change has been made recently In the dty portion of the driving to avoid some of the more congested streets and the average speed over the course is now about 30 mph or much closer to the value obtained when the course was originally set up In 1970. To compensate for these variations In speed In recent testa, the relationship between speed and fuel usage was determined by linear re gression analysis and all fuel consumption data were normalised to an average conns speed of 24.4 mph. Performance and Fuel Consumption of 1970 to 1973 Can Performance In terms of acceleration times for the six car fleet hes deteri orated In the pest four model years as shown In Table 11. An Increase of 13 per cent In acceleration time occurred between the 1970 and 1971 models. This Increase probably is associated with the reductions In compression ratio end other changes made to meet the emission standards. Small Increases were seen also between M PPH 1 0 m mm LIA15502 I i j; : i- Sr r w $ ,-i Si I J 1 1 1971 tad 1972 model! and 1972 and 1973 model!. When the cumulative Increeae from 1970 to 1973 waa calculated baaed on the individual changea in each year, the acceleration timea apparently Increased 23 percent. In view of this rather large change In vehicle performance, the 1970 vehicles which had bean retained at Du Pont ware run in direct match against the 1973 vehicles In early 1973. These evaluations showed (hat the differences between the 1970 and 1973 fleets ware only 10 and 11 peroent rather than 22 and 23 percent. Although the vehicles were checked thoroughly and adjusted to meet manufacturer's specifications, no SKplanetton was found for the fact that the 1970 vehicles wars not capable of repeating the acceleration times that they bed displayed when they were relatively new. Perbape TABLE 9 MEASURED WEIGHT OF CARS USED IN PROGRAM Weight Determined With Full Fuel Tank and a Constant Allowance For Driver Car Make A C D E r G Average 1970 4.390 4,940 4,040 4,360 3,760 4,220 4.363 Model Year 1971 1972 4.470 6,050 4,690 4,400 3,600 4.210 4,403 4,920 9,070 4,660 4.450 4,110 4,220 4,905 J2ZL 4,610 6, SM 4,620 4,690 4,230 ia222 4.661 TABLE 10 URBAN-SUBURBAN FUEL CONSUMPTION ROAD COURSE Miles Time, Minutes Speed, mph Cltr 6 44 12.2 Suburbe IT 61.0 ,Qyra 26 64 24.4 rnmmm mm mm IS <p ~--,-t~- - UIM5503 TABLE 11 ACCELERATION TIME CHANGES 1970 TO 1973 Year Of Test 1970 Models Tasted 1970 1971 Acceleration Time 2Z&. 10. T 13.3 T.l 9.9 Increase, Peroent 13 19 1971 1971 1973 13.9 13.3 9.9 9.9 Increese. Percent 39 1973 1973 1973 13.9 13.9 9.9 10.1 Increase, Percent T9 Cumulative Increase 1970 to 1973, Peroent 1973 1970 1973 Increase, Peroent 33 11.4 13.9 19 33 9.9 9.9 11 t the accumulation of approximately 30,000 mile* had caused some deter!oration la engine performance which was not detectable by conventional diagnostic techniques. However, It la clear that there has been a significant decrease in vehicle performance between the years 1970 and 1973 and the acceleration times of vehicles have increased by at least 10 percent. Approximately S percent of this Increase Is due to the Increase in weight of the cars from 1970 to 1973 and the remainder is due to decreased power. In this report we have chosen to express fuel usage In terms of fuel consump tion. The expression fuel economy or miles per gallon tuta been commonly used Is the past but fuel consumption or the amount of fuel used per mile Is a more meaningful measure of the effect of various vehicle changes on the demand for gasoline and re lates directly to the utilization of natural resources. Fuel consumption is expressed as grams per mile because of the familiarity of this term in reference to exhaust emission measurements. M SP* m Fuel consumption of the 1973 cere Is greater than for the corresponding 1970 cars as shown In Table 12. Fuel consumption Increased each year, ranging from 6 to more than 9 percent more. The cumulative fuel consumption Increase between 1970 and 1973 calculated based on the Individual changes for each year was 24 peroent. Because of the Implications of changes of this magnitude it was decided to make a direct check between the 1970 and 1973 model oars. The fuel consumption of 1973 cars was 14 percent greater than 1970 ears on a direct knatch basis. All of the fuel consumptions were regressed against average test speed and all data normalised to an average vehicle speed of 24.4 mph. The fleet average fuel consumption data are given in the lower part of Table 12. To further check these measurements, triplicate emission teste were made on each of the vehicles and the fuel consumption calculated baaed on exhaust emission analysis while conducting the 1975 CVS Federal emission test procedure. These dsta are shown in Table 12. Again, the fuel consumption increase was 14 paroant far the 1973 models when compared with the 1970 model vehicles. TABLE 12 FUEL CONSUMPTION BY MODEL YEAR Year Of Speed Test mph 1970 28.6 1971 24.9 1972 24.4 Models Tested 1970 1971 1971 1972 1972 1973 Economy Miles/Gel 14.1 13.1 13.1 12.4 12.7 u. S Fuel Usage Percent Consumption Loss Crams/Mile Percent Increase 199 7 214 2 214 S 224 221 9 242 9.2 Cumulative 1970 to 1972 1973 14.4 1970 1972 13.9 11.2 19 12 212 242 24 14 1972* 1970 1972 13.3 11. T 12 211 229 14 * Calculated from exhaust analysis during CVS 1971 Tast Procedure 17 PI oxAfrtta. mmmmmKmmmmmm LI A 15505 - -*--------^ The discrepancy between the direct determination* of tha fual consumption of the 1970 and 1973 vehlclea and tha calculated cumulative effect baaed on individual model year comparlaooa haa not been explained at thla time. However, It la believed that the moat recent data, becauae of the fleeter number of teate and the feet that direct match teala were made, axe more accurate. About one-third of the Incxeaae In fuel consumption of the alx care between 1970 and 1973 waa determined to be due to lncreaeed weight. The other two-thlxda of the Increase waa due to other changes which had been made to control etnlaalone. The effect of Increased weight on fuel consumption waa determined directly. The weight of the 1970 vehlclea waa Increased approximately 500 pounds by placing weights, equally distributed, in the front and rear passenger compartments. Replicate, direct match fuel consumption measurements were made with the 1970 vehicles with and without the additional weights. The average fuel consumption data for the Individual 1970 and 1973 vehicles were normalised to an average speed of 14.4 mph and are abeam In Table 13 and Figure 4. The fuel consumption for the 1970 vehlclea plus a sufficient amount of weight so that they equalled the weight of the 1973 vehlclea la given also. The Increase in fuel consumption of the individual 1973 cars ranged from -1 percent to 15 percent greater than for the 1970 cars at equal vehicle weights. The ala-car fleet average increase in fuel consumption at equal weight was 9.4 percent for the 1973 care compared with the 1970 cars. The 9 percent Increase tn fuel consumptioo and the 10 percent Increase In acceleration time can be attributed to the reduction in compression ratio and other engine change* to meet emission standards. If vehicle performance had been held constant, the Increase in fuel consumption would have been even greater. t wiio.ito n>. He 4 - FixI Economy Wxmi* on tMw- MoWi RooS Covm ei 1970 VilnSm. 1S70 ViMh Eiwpi MW* Wli^U *0 Un* 1*73 VXuctm. *nS 1971 VfSxtm. ( UA15506 TABLE 13 EFFECT OF EMISSION CONTROLS ON FUEL CONSUMPTION. 1970 TO 1973 Averse* Speed >4.4 mph 1970 A 1970 A >80 Lbe 197S A 1970 C 1970 C 440 U 1973 C 1970 D 1970 D 180 Lbe 1973 D 1970 E 1970 E * 320 Lbe 1973 E 1970 r 1970 F * 470 UM 1973 r 1970 G 1970 G 80 Lbs 1973 G Avg 1970 Avg 1970 * >91 Lbt Avg 1973 Economy Mtles/Osl 11.7 11.4 10.3 11.0 11.0 11.3 11.0 11.0 10.0 13.8 13.1 11.4 13.9 13.7 11.3 13.4 16.3 13.9 13.0 13.3 11.3 Percent Loss 7.9 - 1.8 10.3 13.0 17.3 9.3 4.1 * At equal vehicle weight Consumption Gram*/MU# >40 >40 M7 Ml >33 S30 >34 >38 MS x> >14 >43 MS SOS >48 183 184 >03 SIS >34 >43 PlfMOt Increase 8.3 - LI 11.3 18.0 >1.0 10.S 9.4 Comparison of Du Pont and EPA Data Another source of data *bowing the effect of emission control system* on feel consumption is the previously mentioned EPA report (8). These fuel economy data were calculated, we understand, by the EPA from carbon monoxide and carbon dioxide measurements made during the 1972 CVS Federal emission test procedure. Moire accurate results would have been obtained If allowance were made for the hydrocarbons emitted -- this is particularly true for the pre-emission control cars which emitted substantially higher hydrocarbon levels than the 1970 and 1973 cars. The data from Table I of Reference 8 are illustrated graphically In the upper part of Figure S sad the 19 m m mm mmmmmm m alsjuteiiiy wg&mmmm LIA1550? .m ......... data corrected for hydrocarbon minions ara ahown In tha lowar part of Figure 8. The fuel economies for the model years 1964 through 1967 ware averaged to give representstire fuel eoonomlea for the model years Immediately prior to tha Institution of Federal exhaust amission controls In 1968. Also shown ara tha fuel eoooomy data for tha years 1970 and 1973. In their report, the EPA averaged tha data for all vehicle weights and oonduded there were no significant differences between 1970 and 1978 vehicles other than a weight effect. However, there are significant differences In the fuel economies of the 1970 and 1973 vehicles when oompered with the pre-controlled vehicles st all vehicle weights above 3, 500 pounds. In our opinion, the scatter In the data for vehicle weights below 3,600 pounds precludes any conclusion as to the effect of model year on fuel economy for these lighter cars. This scatter may be due to the lack of a sufficient number of data points for these lighter weight vehicles and the wide differences In tha types of vehicles represented. Above 3,500 pounds, most of the vehicles are the conventional U. 8., standard size sedans equipped with a relatively large displacement engine and an automatic transmission. The Du Pont data showing i fuel consumption Increase of 9.4 percent from 1970 to 1973 for a nominal 4.600 pound vehicle appears to be In reasonably good agreement with the EPA data. The fuel consumption data from the EPA study obtained from the faired curves corrected for hydrocarbon emissions shown In Figure 8 are given in Table 14. Also shown are the data from the Du Pool road test at s vehicle weight of 4,663 pounds which was the average weight of the 1973 test fleet. The fuel consumption of the 1973 vehicles compared with the 1970 vehicles Increased from Just under 4 percent (or the 3,500 pound vehicles to more than 9 percent for the 6,500 pound vehicles. The EPA data corrected for hydrocarbon amissions comparing the ..... ...... 90 *4PPP!P*P*P9 * i i Ft*- FmIEconomyel 1964m tt71 VSMn CSeliui (reel tmlnlse Tie IMe by WIM. a mi m ii i Mrnjmmmmmm p*PMPpSiiPilpl|qR9Rli^^ LIA15508 TABLE 14 EFFECT OF EMISSON CONTROLS ON FUEL _______ CONSUMPTION. 1970 TO 1973 Analysis of EPA Report (8) Corrected (or Unburned Hydrocarbons Welebt. Lbs Economy Mlles/Gal 1970 1973 Fuel Dww Consumption Perosnt Grams/Mil# Lose 1970 1*73 3.500 4,000 4,500 4.653* 5,000 5,500 13.3 11.7 10.6 12.5 13.7 11.0 9.9 1L1 3.7 9.9 6.8 M 313 331 340 355 365 383 224 345 9.9 9.1 9.4 8.6 8.1 8.5 393 308 398 329 *Du Pont road teste. average weight of 1973 fleet PlTOIBt Increset 9.6 9.2 6.6 li 6.6 9.4 1973 vehicles with the pre-emission control 1964 to 1967 vehicles are shown la Tafale IS. Fuel consumption Increased from 7 to 20 percent dependent on vehicle weight. These data illustrate the effect of reduced compression ratios and emission control systems on fuel consumption because the comparisons are made at equal weight. Weicht. Lbs 3.500 4,000 4,500 5,000 5,500 TABLE 15 EFFECT OF EMISSION CONTROLS ON FUEL CONSUMPTION. 1964-67 TO 1973 Analysis of EPA Report (8) Corrected for Unburned Hydrocarbons Economy Mlles/Gsl 1964-67 1973 Fuel Ussre Consumption Percent Grams/Mile Loss 1964-67 1973 13.6 12.4 11.6 10.9 10.3 13.7 11.0 9.9 9.1 8.8 6.6 11.3 14.7 19.8 16.9 306 3X1 226 355 243 263 357 306 272 326 Perosnt Increase 7.3 12.6 16.9 19.8 19.9 II tmim i 1 * &I ... . '-........^ m.I.--M'. -- .... ....... .............. ... ................. . . .....----- - . t i i uarMataiiwa&i^ jMmSsmmiaii Eitimated Fuel Coroumptioo Losses from Pre-1968 Through 1976 Models Tb Information from the previous section csn be used to quantify the effect of compression ratio reductions and emission control systems on fuel consumption for systems already in use. Information provided by the automotive companies and various study groups commissioned by the EPA to study future control systems can be used to project the effect on fuel consumption of future emission control systems which meet the U. 8. 1970 emission standards. The fuel consumption Increases from the previous section have been plotted for Figure 6 for an average 4.500 pound vehicle. The penalties would be greater for a heavier vehicle and would be leaa for a lighter vehicle. The cumulative Incream in fuel consumption through 1979 model year as compared with pre-emlsalon control cart la 17 percent. This Increase la due to many factor* ouch as changes hi carburet!on, spark timing, compression ratio, valve timing, and the Introduction of exhaust gas recirculation In the 1973 model car*. The Increase however does not contain any component related to vehicle weight. Projections of Increases In fuel consumption beyond the 1973 model years are difficult in that prototype 1975 and 1976 vehicle* are not available for test at this time. However, during testimony at the recent remand hearings before the EPA, the automobile manufacturers discussed the fuel economy losses that would be encountered In their best effort 1975 prototype vehicles <12,13,14). Their estimates for the fuel economy lots for the 1975 models when compared with the 1973 models ranged from 0 to 10 percent. We have assumed an average value for the loss between 1973 and 1975 of 5 percent In term* of fuel economy. This loss, coupled with previous penaltiesresuits in a cumulative Increase in fuel consumption from pre-1968 models to the 1975 models of 24 percent. The imposition of stringent nitrogen oxide emission controls in 1976 will bring about a further increase in fuel consumption. It has been estimated that the decrease in fuel economy would range from 5 to 20 percent comparing the 1976 models with the 1975 models <15.16,17). Again, we have assumed a median value of 10 percent economy loss between the 1975 and 1976 vehicles. This penalty results in an overall increaat in fuel consumption of 42 percent for the 1976 vehicles compared with pre-emission The foregoing discussion illustrates the extent of the Increased fuel consumption penalties that reduced compression ratio* and emission controls havs caused sad are anticipated to cause in the future. Current model full size American built cars uss approximately 17 percent more fuel than pre-emission control models and it Is antici pated that by the time hydrocarbons and carbon monoxide have been decreased to the 1975 interim California levels the total penalty In terms of Increased fuel consumption will rise to approximately 24 percent. Imposition of the very stringent NO standard In 1976 as mandated by the Clean Air Act Amendments will cause the Increase In fuel consumption to total 42 percent when compared with pre-eml salon control vehicles. The amount of the Increase probably will be somewhat different with different kinds of amission control systems but the major change will take place with the scheduled imposition of the more stringent standards In 1976 as shown in Figure 6. yeiwiii.Liiwiii.il - " - *W' ' --- * r . --- 'r'.7 " / - " m LIA15510 S**P"* '' *Ti |>.K-.1 f n^.w.se. - - fa mnMtrn. 2 3 1 '3 Increases up to 42 percent In the gasoline consumed by vehicle* require that the need for euch stringent automotive exhaust emiaaloe standards aa mandated by the Clean Air Act Amendment* of 1970 be examined critically. If the ambient air quality ataadarda can be met with let* stringent emiiaioo control, great saving* la domestic crude oil sad decreased demand for imported crude oil will be realised. TOTAL EMISSION CONTROL SYSTEMS A atomobile exhaust emlstioo standards sufficiently atrlngent to achieve ambient air quality- standard* are significantly lower than the current U.8. ataadarda (for 1973) thua requiring some form of exhaust treatment device for conventional engines. Both catalytic and thermal reactor emlealon control systems can provide the required degree of control. However, most catalytic systems require lead-free gasoline and this restriction results in increased crude oil use. If lower octane unleaded fuel Is used, the compression ratio of the engines must be reduced result ing in higher fuel consumption. If current octane quality ia maintained with unleaded fuel, more crude ii required to produce a given volume of gasoline. On the other hand, emission control systems based on thermal reactors are compatible with leaded fuel, and high compression ratios which results in minimum fuel consump tion. Thus, if both systems can meet the necessary standards and both Impose aa equal fuel consumption penalty due to the modifications to the engine that must be made to enable the control system to function properly, the thermal ay-stem used with leaded gasoline will result in the lowest overall energy consumption. Also, the thermal system can be engineered to last the life of the car without added maintenance such as catalyst replacement. The development of the first and second generation total emission control systems or TECS I and TECS II was described la an earlier publication (IS). The TECS I vehicles were designed in 1969 and 1970 to meet the then existent exhaust emission standards for the 1975 model year aa set forth by the U.S. government and by the State of California. After the passage of the Clean Air Act Amendmenta (A 1970 a second generation system, TECS n,-was developed in an attempt to meet the more stringent levels for 1975-1976 mandated by the Act. Recently, the TECS m system has been developed to meet emission levels compatible with the attainment of the ambient air quality standards while minimixing the fuel consumption penalty. i 11 PP*P m ppm j ib s mi A1 i LI A15511 diHiUM fiBOMB TECS I - the first generation vehicles were successful to masting the goals of the former 1975 U. 8, and California standards. Six TECS I vehicles of Car Maks A were operated in a 10-month field test by the California Air Resources Board. The fleet average emission levels remained below the former 1975 standards throughout this test. Extended operatic* of the TECS I vehicles revealed two major problems. First, fuel consumption was significantly higher than comparable unmodified pro* duedoe 1970 vehicles. During the 10-month test conducted In California the TECS 1 vehicles used 17 percent more fuel than did the unmodified production vehicles. The second problem was excessive wear an various parts of the engine caused by the recirculation of metal oxides from the exhaust system beck into the engine with the exhaust gas recirculation gate*. Two solutions to this exoesslve wear problem ware proposed In our previous publication (18) but neither solution had been demonstratad in extended vehicle durability testa. TECS n - the seoond generation vehicles Included Car Maka A. a full size sedan equipped with a V-8 engine and automatic transmission, and Car Make B, a sub-compact equipped with a small four-cylinder engine and manual transmission. The TECS n vehicles approached but did not meet the emission levels required by the 1976 standards. Hydrocarbon levels were below 0.25 gram per mile but carbon monoxide levels were about 6 grama per mile and nitrogen oxide levels wars about 0.6 gram per mile. To meet the very low nitrogen oxide levels, carburetors were operated very rich which Increased fuel consumption. Car Make A used 34 percent more fuel and Car Make B 20 percent more fuel when compared with respective unmodified production vehicles. TECS IB - In light of the studies showing that less stringent emissions standards than those mandated by the Clean Air Act probably would achieve national ambient air quality standards and the growing concern over the Increased utilisation of fuel by low emission cars, it was decided to develop a third generation total emission control system or TECS 111. The goal of this program was to achieve emission levels considered adequate to meet national ambient air quality standards In major urban areas while minimizing the fuel consumption penalty' which usually accompanies the attainment of such low emission levels. An additional goal was that the components selected for the system demonstrate the potential U> operate for the life of the vehicle with no significant added maintenance and with virtually no deterioration In emission control. These criteria resulted In the selection of the same general systems used for the TECS I and TECS 11 vehicle*. Exhaust manifold thermal reactors were used to control hydrocarbon and carbon monoxide levels because of their demonstrated potential to meet low emission levels for long periods of tlms. Exhaust gas recir culation was used In combination with modified carburet!on and ignition ttmiig to control nitrogen oxide levels because EGR bad been shown to be effective In controlling nitrogen oxide levels, to be compatible with the use of exhaust manifold reactors, and 14 n uyu ppj rnmmmmm to operate satisfactorily (or extended mileage*. The fine! component chosen wee e muffler lead trap aleo previously deacrlbed In an earlier publication. The exhauat lead trap would permit the uae of leaa expenalve, high octane leaded gasoline* enablinf the continued uae of higher compreaalon ratio, more efficient engines, while significantly reducing the amission of lead compound* to the environment (19). la addition to the control ayatera component* Juat described, all vehicles were equipped with production, closed positive crankcase ventilation systems and evaporative emission control aystems. Design of TECS III i Car Make* A and B ware choeen for the development of TECS tn beceuae of our experience with these vehicles and the fact that they represented both current production standard site vehicles equipped with V-4 engines and automatic trans missions as well aa the sub-compact cars representative of both domestic and foreign production. A description of the TEC8 01 vehicle* and the type of control system installed la summarised la Table IS. . TABLE 1> TECS m VEHICLES 1 Car Make A Car Make B t Vehicle Four-door sedan 4, BOO Two-door hardtop 2,250 p- pounds pounds Engine 350 CID V-8 1600 cc In-line 4 cylinders Transmission 3 Speed automatic 4 8peed manual r Thermal Reactor Modified Type Vin Insulated Type V shielded with air with air injection injection 1 EGR Below throttle, -- 10 percent Above throttle, 13 peroent li Tnpe None Muffler lead trap - Carburet! on Moderately enriched, feat Moderately enriched, feet 5 release choke release choke Spark Timing Modified vacuum advaaoe on start up Modified vacuum advance on start ig> ' i Jk I iieiienmit LIA15513 TECS in for Csr Make A It shown schematically In Figure 7. The exhaust manifold reactor* shown In Figure 0 were modification* of the Type VIH Insulated reactor previously described (10). The Interior core at the reactor Is a large diameter open chamber with a single baffle located across the extended outlet pipe. The exhaust gases enter the oore through extended exhaust ports and exit from these ports through rectangular alots which contain directional vanes. The core consisted of concentric, double walled cylinders to reduce the beat loea from the inner core to the outer shell of the reactor. To further reduce heat loea the outer shell and outlet pipe from the reactor were covered with one-half Inch of fibrous o*ramie Itwulatloo. Secondary air was Injected into the exhaust ports end into the ends at the reactors to provide an overall ooddicing atmosphere. The exhaust gas recirculation system for the Make A TECS HI vehicle utilised two 1973 production EGR valves for this make vehicle. Exhaust gas was taken front the exhaust pips ahead of the muffler on one side of the dual exhaust system, routed through the two EGR valves in parallel, and Introduced below the secondary throttle plates of the four-barrel carburetor. The EGR valves were operated by manifold vacuum obtained from a port In the carburetor and were turned off at Idle end at wide open throttle. A modified version of the production four-barrel carburetor normally ased for this engine was employed. Metering was set to give a maximum vacuum air-fuel ratio at idle and a gradual leaning of the air-fuel ratio at higher speeds reaching aa air-fuel ratio during cruising speeds of SO to 60 mph somewhat In excess of 13 to 1. The production intake manifold was replaced with s dual-passage Offenhauaer mani fold and the Intake system heat was supplied by engine coolant routed directly from the outlet of the engine through the internal passages In the Intake manifold. A production 1970 distributor was used but the basic timing was advanced 4' from U manufacturer's specifications for 1970 to improve fuel economy. The TECS 111 Installed on Car Make B la shown schematically In Figure 9. The thermal reactor, shown In Figure 10, was a Type V exhaust manifold reactor modified to fit the Car Make B engine. This reactor contained an inner core to promote mixing of the air and the exhaust gases and a double walled beat shield to reduce heat loss to the outer shell. No external Insulation was used. The exhaust gas recirculation system for Car Make B Is shown schematically in Figures 10 and 11. The exhaust gas was withdrawn from the exhaust ports in tha Immediate vicinity of the exhaust valve. The Individual lines from each of tbs four ports were manifolded together to take advantage of the exhaust blowdown process to force the exhaust gas through the EGR line. A vacuum operated, on-off valve prevented exhaust gas recirculation during cold start up. Exhaust gas was delivered to the carburetor below the venturi and above the throttle plate. The carburetor used on Car Make B was selectively enriched throughout the metering range to mid in the control of nitrogen oxide emissions. A vacuum spark advance control system sensitive to coolant temperature was Incorporated to prevent manifold vacuum advance during cold starts until the coolant reached normal operating temperaturea. Hi \ LIA1 5514 ; nr iiiaiiPaifcagaiMfi*^^ TlWaMtl MACTOat ' mun mi ft*. 7 - TCCt IN aaCar M*a A. ft* -- ModfW Typg VIIITkm* I Car Mai A. n**-TECS III Car Mafca ft. " p m wp p p y iip ^ p jp w ii|]j ,|pi |i ii i| i i .ii| u i | ii|ijHi i miii> m ii M P* ft* 11 -- COR *rftant for Car Maka S. WP*WiPiPPI H'B If i irl-Wanifllirll u^fiiyiyjijpLijppw LIA15515 j**-***^-1"^^ ii Wwj^iiiP j^ fpjiiiiPi^WBiiwpP|wpwBpwiWipw^wPi^fWW^^ i w i ii'iii ' P n w i'Mf i m wiiiii . m niiii ii s m m * H 8 - Muffin LmM Tr*e ts CM MMa B. The trapping system installed on Car Make B c o d talced Quted pipe from the outlet of the exhaust manifold reactor to the rear of the car to help cool the exhaust Bases. The conventional muffler was replaced by the muffler lead trap shown In Figure 12 (19). The trap was the same alre and shape aa the production muffler and was located in the same place. The trap contained the bed of alumina pellets which agglomerated lead particles in the exhaust stream into large particles which could be separated from the exhaust gas stream by the twin cyclone separators and stored la collection chambers. The chambers had sufficient capacity to bold all the lead salts collected during 100,000 miles of operation on conventional leaded gasolines. Emission Control with TECS III Car Make B equipped with TECS Dl baa recently completed a 50,000-mils durability test involving both road and laboratory chassis dynamometer operation. The road mileage accumulation consisted first of a 4,000-mlle, cross-country trip from the east coast to Denver, to the continental divide, and bade to the east coast. For the remainder of the mileage accumulation teat the vehicle was driven during the daytime on an urban-suburban driving route in the South Jersey area. During the evening and nighttime hours mileage waa accumulated on the programmed chassis dynamometer following a simulated turnpike driving schedule with speeds varying It m ........ ,, .......... . - ' LIA15516 between 40 tad 60 mph with aa average apeed of 50 ir.ph. An unmodified production veraion of Car Make B waa run aa a companion car with all of ita mileage being accumulated in a aimilar manner except that It did not make the croae-oountry road trip. Commercial gaeoline containing 2.2 grama of lead per gallon and conventional multigrade lubricating oila meeting the manufacturer'a apeciflcatioca were uaed for these teeta. Emlaaion levels of both the unmodified vehicle and the vehicle equipped with TECS in were obtained at periodic intervale. The hydrocarbon, carbon monoxide, and nitrogen oxide levels from both vehicles throughout the SO, 000-mlle teat are shown in Figures 18,14, and IS. The average emlaaion levels for the SO, 000-mile teat are shown in Table IT. Fie 11 - HyWoearboo tmioM far Car Main I Donna>0.000 Mil Tan. F% M - Carbon Monoriba Eomaiona far Crr Mbtt Donna 60.000 Mila Tan. Fie IS - NitrotM Oatba timmonr far Cat Main I Ourinf 60,000--Mia Tad. wmmmm. rm 8* ve&^^iatitakiftaa-- -~ TABLE IT EMISSION LEVELS OF CAR MAKES A AND B WITH TECS HI Car Make A Car Maks B Suggested Emission Levels Needed To Attain Air Quality Standards EmIion Levili, Grams Par Mila 1975 CVS Teat Procedure CO -PC..- 10. 0.TS 4.7 0.S1 1.0 l.S 15-40 0.4-0.0 l.ft-0.0 The average emission levels from replicate tests conducted with Car Maks A equipped with TECS m are shown la Table 17. Also included are the emission levels previously indicated to be needed to attain the ambient air quality standards. The emission levels from Car Makes A and B with TECS m are below the needed emission levels and It Is clear that the emission control system technology rep resented by the TECS m vehicles Is capable of reducing all of the exhaust emission pollutants to very low levels. Also, exhaust emission levels well below those indicated as be tag needed to achieve the ambient air quality standards can be maintained for at least SO, 000 miles. Fuel Consumption and Vehicle Performance Improvements in carburet!on and Ignition timing incorporated in the TECS in vehicles have greatly reduced the fuel consumption and performance penalties that were associated with the earlier first and second generation total emission control systems. The fuel consumption for the TECS III vehicle of Car Make A Is given Is Tabic 18. These values were obtained from replicate measurements made during TABLE 18 FUEL CONSUMPTION OF CAR MAKE A WITH AND WITHOUT TECS in Average Speed 00 mph Economy Miles/Gal Unmodified 1970 Production 14.3 Unmodified 1973 Production 13.3 TECS HI 13.3 'Compared with 1070 Fuel Uease Percent Coosumption Loss* Grsms/MIls Percent Increase* 194 7.6 SIS 0.3 7.0 313 0.3 SO ipseiepwtfepews^wigippse^pss IM Pi .u,u.. mmm'nmmw 'i n m r liiiiiiirthiru11 i>Mhifriitti^'rfiirfgirifini ^ LIA15518 tagwaBstii. an >iiiiiiil flli fiftm f i 3 direct match tests over the urban-suburban reed driving course aa prevloualy deacrlbed. The fuel conaumptlon penalty for Car Make A equipped with TECS 0! wae 8.2 percent when compared with the 1870 unmodified production vehicle. Thia Improvement in fuel conaumptloo la all the more aignlflcant when It la compared with the unmodified 1873 production vehicle aince the fuel consumption for the TECS HI waa equivalent to that of the 1*73 production vehicle. The performance of Car Make A unmodified and equipped with TECS Dl la abown In term a of wide-open-throttle acceleration time* la Table 18. The TECS ID vehicle was almost equivalent to the unmodified 1870 production vehicle la accelera tion performance. The fuel consumption of Car Make B equipped with the TECS m system la compared with the unmodified production vehicle in Table SO. Again, the results TABLE IS PERFORMANCE OF CAR MAKE A WITH AND WITHOUT TECS 01 Wide-Open-Throttle Acceleration Times, In Seconds. Level Road 0-&0 mph 50-70 mob TECS 01 Production 1S.S is. a l. 8.4 Increase, Percent 4.S 4.4 TABLE SO FUEL CONSUMPTION OF CAR MAKE B WITH AND WITHOUT TECS m Average Speed Si. 4 mph 0 Miles Unmodified 1871 Production TECS m Economy Miles/Gal 25.0 S2.4 Fuel Usage Percent I out Consumption Grama/Mile 10.4 US 125 24.000 Mllee Unmodified 1871 Production TECS m 2S.S 84,2 4.4 111 110 66.000 Mllee Unmodified 1871 Production TECS m 24.0 22.8 S.0 117 1SS Average for TEC8 in 0.0 Percent Increase 11.0 4.S 8.1 7.1 SI mmmp mm m mmmm. LIA15519 represent replicate match teats an the urban-suburban road course. Improvements In the TECS III system In terms of carburetor metering and ignition timing resulted In an average fuel consumption penalty of 7.1 percent as compared with the unmodified production vehicle. It is expected that additional improvements la carburetor meter ing and ignition timing will reduce this penalty to an even smaller value. The performance of Car Wake B la terms of acceleration times with the TECS IQ is compared with the unmodified productloe vehicle la Table Zl. Minor improvements in ignition timing, earburation, and, moat importantly, a significant reduction in the pressure drop across the muffler lead trap when compared with the lead trap incorporated in the TECS IX vehicle resulted In a significant Improvement la acceleration time for the TEC8 ill vehicle. When compared with the unmodified vehicle the TECS in car had an 11 percent increase la wide-open-throstle acceleration time. TABLE Zl PERFORMANCE OF CAR WAKE B WITH TECS m___________________ Wide-Open-Throttle Acceleration Times, In Seconds. Level Road 0-60 moh Unmodified 1*71 Product!on TECS m Increase, Percent ssa Zl.* 11 Based on these results it is clear that emission control systems which are capable of reducing emission levels on both large and small vehicles to values which apparently are compatible with meeting the national ambient air quality emission standards have been developed. Furthermore, these emission control systems im pose only minor penalties in terms of both fuel coosumption and vehicle performance when compared with unmodified production vehicles. These sy stems are compatible with the continued use of leaded gasoline and thus the motorist can gain the benefits of less expensive gasoline and higher compression, more efficient engines. Performance of Lead Trap* Lead traps can be used in conjunction with thermal reactor baaed emission control systems to reduce the emission of lead to the environment. Total lead emissions can be reduced by 80 to *0 percent and airborne lead particles by 65 to 75 percent with the systems developed by Du Pont (1*). M nr-'.'w mmmm LIA15520 m TABLE 22 TOTAL LEAD EMISSION RATE FROM CAR MAKE B WITH AND WITHOUT TECS PI Average Total Lead Emission Rate thirlng 50.000-Mile Teata Grama Per Mile Reduction. % Unmodified 1971 Production TEC8 m 0.0S48 0.0003 03 Lead emission rataa from both the unmodified Make B veftie and the vehicle equipped with TECS IB were meaaured throughout the 50,000-mil# teat according to procedurea previoualy deecrlbed (20). The average total lead emleeian rate for the two vehiclea la ahown In Table 22. The muffler lead trap ayetem produced an 82 percent reduction In the total amount of lead emitted over the 50,000-mile teat. Lead size dlatrlbutloo meaeurementa were made on both care at approximately the mlt^ point and the end-point of the teat. The lead emlaaioo rates In the different particle size categories for the two vehicles are shown In Table 23. The muffler lead trap was extremely effective reducing the larger alze particles by better than 97 peroeat. More Importantly, it was also very effective In reducing the size particles which would be expected to remain airborne for significant lengths of time. Even for the finest particles, those below 0.3 microns in diameter, the lead trapping system effected a 77 peroent reduction in lead emissions. TABLE 23 SIZE DISTRIBUTION OF LEAD EMI86ION8 FROM CAR MAKE B WITH AND WITHOUT TECS IB Unmodified 1971 Product!oe 20.000 Miles 51.000 Miles Average TECS m 26.000 Miles 51.000 Milaa Avarage Reduction, Percent Lead Emission Rate. Grams Per Mua Size Ranee in Micrometers > 9.0 1.0 to 9.0 0.3 to 1.0 < 0.3 0.019 0.013 0.016 0.018 0.016 0.017 0.0005 0.0003 0.0004 67.8 0.0016 0.0029 0.0022 67 0.024 0.037 0.030 0.036 0.051 0.044 0.0034 0.0049 0.0036 68 0.0076 0.0129 0.0102 77 33 rnmmmmm joutihWiMiMAifiCaiMa mmmmmmsmmmmmm LIA15521 rtfttrif-ifiBi m* tm m rn rn ltm i l < H i i m .lli.. mi-- imaiMlMilttMlliMfcJiil The muffler lead trap* have been evaluated on unmodified production versions of Car Make A. Traps were Installed on two vehicles and they were operated for 50,000 mile* on a conventional leaded gasoline containing 2.2 grams of lead per gallon under the modified AMA mileage accumulation cycle on a programmed cha sals dynamo meter. The average lead emission rate for the cars equipped with the muffler lead traps and for the unmodified vehicles equipped with only the standard muffler are shown In Table 24. The traps reduced total lead emis sloes by 87 peroent. Lead else distribution measurements were made from the vehicles equipped with the muffler lead trap at approximately 25,000 miles and the data along with corresponding data from an unmodified production vehicle are shown in Table 25. As In the cnee of Car Make B, the muffler lead traps were extremely effective, reducing the larger particle sixes by 88 percent and reducing the smallest else particles by 81 percent. -3? 1 24 'mm mm TABLE 24 TOTAL LEAD EMISSION RATE FROM CARS OF MAKE A WITH AND WITHOUT MUFFLER LEAD TRAP Unmodified 1870 Production Two 1870 Production Vehicles With Muffler Lead Trap Average Lead Emission Rate During SO. OOP-Mile Teste Grams Per Mile Reduction. % 8.108 0.014 07 TABLE 25 SIZE DISTRIBUTION OF LEAD EMISSIONS FROM CAR MAKE A WITH AND WITHOUT MUFFLER LEAD TRAP Lead Emission Rate, Grama Per Mile Sire Range in Micrometers > 9.0 1.0 to 9.0 0.3 to 1.0 Unmodified 1870 Production 0.038 0.023 Two 1870 Production Vehicles Vehicles with Muffler Lead 0.00063 0.0030 Trap 0.00084 0.0020 Average 0.00073 0.0025 Reduction, Percent H 88 0.010 0.028 0.004 0.002 0.003 85 0.010 0.011 0.011 81 w mmmmm ......... ...-, - mu |1 U l LA_ ......................------------------------,- m 9 HP LIM552Z ' IffiifWBsin t maft--Mfigtsg rii4 CONCLUSIONS The automotive exhaust emissions standards mandated by the Clean Air Act Amendmenta.of 1970 appear to be more stringent than necessary to attain the ambient air quality atandarda In major urban areas. Baaed on trends in ambient air levels, traffic, and automotive emission rates the following exhaust emission standards based on the 1975 CVS Federal Test Procedure appear to be adequate to meet the ambient air quality standards: Carbon Monoxide Hydrocarbons Nitrogen Oxides 15 to 40 Crams Per MB# 0. 4 to 0.8 Gram Per Mila 1. S to 3.0 Crams Per Mila Current 1973 model standard else cars use from 7 to 20 percent more gasoline per mile than comparable pre-emlsaioo control cars. This penalty In fuel consumption Is predicted to double if emission controls meeting the 1974 standards mandated bv the Clean Air Act are used. If vehicle emission standards were changed to the values suggested above ae being adequate to attain ambient air quality atandarda, Doncatalytic exhaust emission control systems based on thermal reactors, exhaust gas recirculation, and engine modifications could be employed. Such systems would permit the continued uae of high octane leaded gasoline giving motorists the opportunity to use the lowest cost fuel In high compression, more efficient engines. The fuel consumption of cars using such control systems Is less than 8 percent greater than corresponding 1970 production vehicles or approxi mately equivalent to the current 1973 production cars. Exhaust particulate traps could be used to control lead particle emlssiona, If needed. The current strategy of requiring all cars to meet very stringent emission standards even though less stringent standards appear to be sufficient to attain the ambient air quality standards even In the worst areas In the country should be reexamined. The critical crude oil supply situation demands that a strategy be developed which assures clean air but is least wasteful of our natural resources. ACKNOWLEDGMENTS The authors wish to acknowledge the contributions of R. D. Snee and J. Zelson who participated In the air quality studies; W. E. Morris and H. J. Russell who participated in the tael consumption studies; I. T. Rossnlund and S. W. Ross who developed the low emission cars; and W. 0. Kuna and V. E. Llberl who developed the muffler lead traps. - j r * * * * - - ............. ........*i l - -- m 4 V 5 insf.w LIA 15 52 3 Tf ^-ifia^-ftite^.rriak^aiMifcaaMi^ ii'inr a^hi1-1Mtt REFERENCES r 1. Environment*] Protection Agency, "Nation*! Primary end Seconfery Ambient Air Quality Standard*," Federal Register, 3f:84, Part 0, 8186 (April >0, 1871). I. D. 8. Barth, "Federal Motor Vehicle Emillion Goal* tor CO, HC, and NO Baaed on De aired Air Quality Levela, " J. Air Pollution Control Asaoe. 20. 518-23 (1070). 3. Cumulative Regulatory Effect* on the Coet of Automotive Transportation RECAT, Prepared for the Ode* of Science and Technology, February, 1872. 4. California Air Resource* Board Bulletin, March-April 1872. 5. C. A. Blase11*. 8. H. Lubore, and R. P. Pflnil, "National Environmental Indices: Air Quality and Outdoor Recreation," Mitre Corp. Report MTR-61S8, 1872. 6. J. M. Plerrard, R. D. 8nee, and J. Zeleon, "A New Method of Determining Automotive Emission Standard*, " Prepared for Presentation at National Meeting, Air Pollution Control Association, June, 1973, Chicago, HUnoia. 7. W. D. Ruckelshaus, "Decision of the Administrator on Remand From the U.S. Court of Appeals for the District of Columbus Circuit," April 11, 1872, and Accompanying Remarks Given in Press Release. 8. "Fuel Economy and Emission Control," U.S. Environmental Protection Agency, Office of Air and Water Programs, Mobile Source Pollution Control Program, November, 1872. 8. Octane Number Requirement Survey 1970, July 1971, Coordinating Research Council, Inc. 10. Octane Number Requirement Survey 1971, November 1971, Coordinating Research Council, Inc. 11. Octane Number Requirement Survey 1972, November 1972, Coordinating Research Council, Inc. 12. F. Bowditch, T. Hustead, R. Sumpel, F. HUder, J. Bldwell, E. Burkinan, General Motors Testimony at the Suspension Request Hearing of the Environ mental Protection Agency, Washington, D. C., March 12-28, 1973. 13. H. Mlsch, D. Jensen, W. Brebob, D. Bell, R. Campau, H. WiUena, Ford Testimony at the Suspension Request Hearing of the Environmental Protection Agency, Washington, D. C., March 12-28, 1972. a 1 ' *r. wm*m m si?--1 Iifififikii iiilfiirViniiiM'iriii if LIA15524 14. S. Tarry, C. Hainan, C. Hubner, R. Goodwillie, V. Tomlinson, Chrysler Taatlmany at tha Suspension Request Hearing of the Environmental Protection Agency, Washington, D.C., March 13-26, 1973. IS. Final Report, "An Assessment of tha Effecta of Land Additives in Oaaollna oa Emission Control Systems Which Might Ba Uaad to Meat tha 1975-76 Motor Vehicle Emission Standards," Prepared by the Aerospace Corporation far the Environmental Protection Agancy, November IS, 1971. 16. "Automotive Emission Control - The State of tha Art as of December 1979" Divtsloo of Emission Control Technology, Mobile Source Pollution Control Program, Office of Air and Water Programs, Environmental Protection Agency, February 1979. * 17. Report by the Committee on Motor Vehicle Emi salone. National Academy of Sciences, February 12, 1979. 18. E. N. Cantwell, R. A. Hoffman, I. T. Rosenluad, and S. W. Rosa, "A Systems Approach to Vehicle Emission Control," SAE 720510, Presented at the National Automobile Engineering Meeting, Detroit, Michigan, May 22-26. 1979. 19. E. K. Cantwell, E. S. Jacobs, W. G. Kuna. Jr.. V. E. Libert. "Control of Particulate Lead Emissions from Automobiles," SAE 720672, Presented at the National Automobile Engineering Meeting. Detroit, Michigan May 22-26, 1972. 90. K. Hablbi. "Characterisation of Particulate Lead In Vehicle Exhaust - Experi mental Techniques," Environmental Science and Technology, No. 3, 239248, March. 1970. 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