Impact of Automotive Trends and Emissions ... - ACS Publications

2 Impact of Automotive Trends and Emissions Regulation on Gasoline Demand DAYTON H,

CLEWELL

Mobil Oil Corp., New York, Ν. Y. 10017 WILLIAM J. KOEHL

Downloaded by UNIV OF SYDNEY on May 4, 2015 | http://pubs.acs.org Publication Date: June 1, 1974 | doi: 10.1021/bk-1974-0001.ch002

Mobil Research and Development Corp., Paulsboro, N. J, 08066

Gasoline i n Perspective In these days of energy shortages, gasoline is probably our most visible source of energy and the automobile, our most conspicuous consumer. In this paper we will trace some automotive trends that have contributed to rising gasoline demand in the past and that can be expected to affect it in the future. We will also point out some opportunities for moderating the future growth of gasoline demand. To put gasoline consumption into the perspective of the overall energy picture, Figure 1 shows total 1971 energy consumption broken down into its major sources and consuming sectors(1). On an equivalent energy b a s i s , g a s o l i n e r e p r e s e n t e d about 17% o f t h e energy consumed in 1971, or about 38% of the oil. Virtually all of the gasoline was consumed by the transportation sector, but not all by automobiles. Gasoline supplied about 68% of the energy required for all transportation. Focusing on the automobile, statistics illus trated in Figure 2 show that gasoline consumption by passenger cars amounted to 74% of total gasoline demand(1,2) or about 13% of total energy. Light trucks, up to 6000 lbs. gross vehicle weight, are estimated to consume about 10% as much g a s o l i n e as a u t o m o b i l e s , o r 7% o f t h e total (3). Although they frequently are used interchangeably with automobiles, we will exclude them from this discussion because they are treated separately from

*Numbers i n p a r e n t h e s e s d e s i g n a t e r e f e r e n c e s a t end o f paper. 1Û

In Approaches to Automotive Emissions Control; Hurn, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1974.

A U T O M O T I V E EMISSIONS C O N T R O L


20

U.S. Department of Transportation

Figure 1.

Patterns of fuel and energy consumption

OTHER, 19% 4—LIGHT TRUCKS 7%* BILLION GALLONS PASSENGER CARS 74% [13% OF TOTAL ENERGY]

1950

1970

1960 YEAR

* Estimated Figure 2.

Gasoline consumption, 1950-1971


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Automotive Trends and Emissions Regulations

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p a s s e n g e r c a r s i n e m i s s i o n s r e g u l a t i o n s f o r 1 9 7 5 and beyond, and because t h e y appear t o be e x c l u d e d from p r o p o s a l s under d i s c u s s i o n i n Washington f o r r e g u l a t i n g f u e l economy.


Car

Trends

The i n c r e a s e i n g a s o l i n e demand shown i n F i g u r e 2 r e f l e c t s changes i n p a s s e n g e r c a r s a l e s and usage. Based on d a t a from t h e U.S. Department o f T r a n s p o r t a t i o n (4), F i g u r e 3 shows t h a t r e g i s t r a t i o n s i n c r e a s e d 45% from 1960 t o 1970 w h i l e m i l e s t r a v e l e d were up s l i g h t l y more a t 51%. G a s o l i n e consumption by p a s s e n g e r c a r s i n c r e a s e d 60% i n d i c a t i n g an i n c r e a s e i n average f u e l consumption p e r m i l e o v e r t h e p e r i o d . Over t h e same 1 9 6 0 t o 1970 p e r i o d ( a c t u a l l y , d a t a a r e shown t h r o u g h 1972) t h e r e were changes i n s e v e r a l a s p e c t s o f new c a r d e s i g n t h a t caused f u e l consumption to increase. As i l l u s t r a t e d i n F i g u r e 4, v e h i c l e weight (_5_) , engine d i s p l a c e m e n t (6J , and t h e p e r c e n t a g e o f a u t o m a t i c t r a n s m i s s i o n s (JJ a l l i n c r e a s e d , b u t n o t by l a r g e f a c t o r s . A t t h e same time these f u e l consuming t r e n d s were o f f s e t somewhat by t h e f u e l s a v i n g t r e n d s o f i n c r e a s i n g compression r a t i o ( 6 ) and g r e a t e r s a l e s o f i m p o r t e d c a r s (_8) . Only a i r c o n d i t i o n e r i n s t a l l a t i o n s ( 7 ) showed a s t e e p i n c r e a s e , but t h e r e s u l t i n g i n c r e a s e i n f u e l consumption was a t a much lower r a t e because a i r c o n d i t i o n i n g i s n o t used a l l o f t h e time. In a d d i t i o n t o t h e t r e n d s shown i n F i g u r e 4, e x h a u s t e m i s s i o n c o n t r o l s emerged w i t h t h e 1968 models (1966 f o r c a r s s o l d i n C a l i f o r n i a ) as a new a s p e c t o f car design. These have had an i n c r e a s i n g l y i m p o r t a n t e f f e c t on g a s o l i n e demand; by 1970 they had r e d u c e d f u e l economy o f new c a r s by about 3%. F o r t h e 1 9 7 3 models, we e s t i m a t e t h a t the t o t a l l o s s i n f u e l economy caused by e m i s s i o n c o n t r o l s averaged about 15%. In t h e f u t u r e , c a r d e s i g n t r e n d s w i l l c o n t i n u e t o i n f l u e n c e average f u e l economy and t o t a j . g a s o l i n e consumption. We e x p e c t e m i s s i o n c o n t r o l s t o c o n t i n u e t o be an i m p o r t a n t f a c t o r . Of t h e f a c t o r s t r a c e d i n F i g u r e 4, w e i g h t c o u l d i n c r e a s e because o f s a f e t y and d a m a g e a b i l i t y regul a t i o n s ; however, t h i s t r e n d may be c o u n t e r a c t e d by i n c r e a s i n g emphasis on w e i g h t r e d u c t i o n wherever p o s s i b l e t o improve f u e l economy. On t h e a v e r a g e , we e x p e c t v e h i c l e w e i g h t t o d e c r e a s e because o f t h e growing p r o p o r t i o n o f s m a l l e r c a r s among new c a r sales. A u t o m a t i c t r a n s m i s s i o n i n s t a l l a t i o n s appear




22

% 100 9 0

v

AUTOMATIC _ TRANSMISSIONS, % ^

- ^ + " 7s

COMPRESSION RATIO*

80 AIR CONDITIONED, % y

PERCENT

SHIPPING WEIGHT, lbs*

f

I

IMPORTS, %

^

1 65

3

0

0

260

DISPLACEMENT Cu.in.*

L 70

•WEIGHTED A V E R A G E , U.S. C A R S O N L Y .

YEAR Figure 4. New car design and equipment trends, 1960-1972



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CLEWELL AND KOEHL


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t o have l e v e l e d o f f and a i r c o n d i t i o n e r i n s t a l l a t i o n s p r o b a b l y cannot i n c r e a s e much more w i t h o u t deep p e n e t r a t i o n i n t o the s m a l l c a r and c o o l e r c l i m a t e markets. Compression r a t i o has a l r e a d y s u f f e r e d a d r a s t i c r e d u c t i o n s i n c e 1970. T h i s change, made t o f a c i l i t a t e i n t r o d u c t i o n o f unleaded g a s o l i n e f o r 1975 c a t a l y t i c e m i s s i o n c o n t r o l systems, a c c o u n t s f o r n e a r l y h a l f o f the 15% f u e l economy l o s s a s s o c i a t e d w i t h e m i s s i o n c o n t r o l s through 1973. Some f u r t h e r r e d u c t i o n i n compression r a t i o c o u l d o c c u r i n the next y e a r o r two t o p r o v i d e adequate knock p r o t e c t i o n i n c a r s u s i n g 91 octane unleaded g a s o l i n e . In the l o n g e r term, a f t e r e m i s s i o n c o n t r o l development has s t a b i l i z e d , compress i o n r a t i o c o u l d be i n c r e a s e d t o r e g a i n some economy and performance; however, t h i s would r e q u i r e premium grade h i g h e r octane f u e l s . Engine d i s p l a c e m e n t w i l l p r o b a b l y i n c r e a s e somewhat i n g i v e n c a r f a m i l i e s t o compensate f o r performance l o s s e s due t o e m i s s i o n c o n t r o l s , but on average, i t may d e c r e a s e because o f the s h i f t t o s m a l l e r c a r s . L a t e r i n t h i s paper we s h a l l make some p r o j e c t i o n s o f growth i n f u t u r e g a s o l i n e demand as a f u n c t i o n o f the two v a r i a b l e s t h a t we see as most i m p o r t a n t i n the s h o r t term - e m i s s i o n c o n t r o l r e g u l a t i o n s and average v e h i c l e weight. The l a t t e r w i l l be d e s c r i b e d i n terms o f the s h i f t from l a r g e r c a r s t o s m a l l e r ones t h a t can be seen d e v e l o p i n g r a p i d l y i n the new c a r market t o d a y . P r o j e c t i o n s o f the p o t e n t i a l e f f e c t s o f e m i s s i o n r e g u l a t i o n s are a l s o t i m e l y , not o n l y i n the c o n t e x t o f t h i s symposium, but a l s o i n the c o n t e x t o f c u r r e n t d e l i b e r a t i o n s on p o s s i b l e changes i n the C l e a n A i r A c t . Gasoline

Trends

B e f o r e p r o j e c t i n g g a s o l i n e demand, l e t us l o o k b r i e f l y at gasoline q u a l i t y trends. These a l s o have been and w i l l c o n t i n u e t o be i n f l u e n c e d by v e h i c l e trends. A l o n g w i t h compression r a t i o , g a s o l i n e o c t a n e q u a l i t y r e a c h e d i t s h i g h e s t l e v e l s i n the l a t t e r h a l f o f t h e l a s t decade; w h i l e g a s o l i n e v o l a t i l i t y showed r e l a t i v e l y l i t t l e change (9J. S i n c e 1970, however, i m p o r t a n t changes i n g a s o l i n e q u a l i t y have begun t o t a k e p l a c e i n response to emissions r e g u l a t i o n s . S e v e r a l marketers i n t r o duced u n l e a d e d grades o f lower o c t a n e than t r a d i t i o n a l r e g u l a r i n 1970 and 1971 as new c a r s w i t h lower compression r a t i o e n g i n e s were i n t r o d u c e d . By J u l y 1, 1974, v i r t u a l l y a l l m a r k e t e r s must o f f e r an u n l e a d e d g a s o l i n e o f a t l e a s t 91 r e s e a r c h o c t a n e number (RON)



24


i n a n t i c i p a t i o n o f c a t a l y s t e q u i p p e d 1975 c a r s ( 1 0 ) . As c a r s r e q u i r i n g u n l e a d e d g a s o l i n e r e p l a c e t o d a y ' s c a r s which can use l e a d e d g a s o l i n e , the average o c t a n e q u a l i t y o f the g a s o l i n e p o o l w i t h o u t l e a d w i l l have t o i n c r e a s e from r e c e n t l e v e l s o f a p p r o x i m a t e l y 88 RON t o 91 RON. Recent r e g u l a t i o n s w i l l a c c e l e r a t e the i n c r e a s e i n the c l e a r p o o l o c t a n e l e v e l by f o r c i n g a r e d u c t i o n i n the l e a d c o n t e n t o f e x i s t i n g r e g u l a r and premium g r a d e s . EPA has o r d e r e d t h a t the l e a d c o n t e n t o f the l e a d e d grades o f g a s o l i n e be reduced from t h e i r r e c e n t average l e v e l s o f about 2 t o 2.5 g / g a l t o a l e v e l such t h a t the average l e a d c o n t e n t o f a l l grades i n c l u d i n g the unleaded g a s o l i n e w i l l not exceed 1.7 g / g a l a f t e r J a n u a r y 1, 1975. The l i m i t w i l l be r e d u c e d i n f o u r more s t e p s t o 0.5 g / g a l by J a n u a r y 1, 1979 (11). T u r n i n g t o v o l a t i l i t y , we do not e x p e c t any l a r g e changes i n the f u t u r e . A l t h o u g h some had been p r o p o s e d t o m i n i m i z e c o l d s t a r t e m i s s i o n s from f u t u r e low e m i s s i o n c a r s , we have n o t seen c o n v i n c i n g e v i d e n c e t h a t t h i s i s the b e s t a l t e r n a t i v e f o r e f f e c t i v e e m i s s i o n c o n t r o l . Advances are b e i n g made i n c a r b u r e t o r and m a n i f o l d d e s i g n t o f a c i l i t a t e f u e l e v a p o r a t i o n and i n d u c t i o n , and a c c o m p l i s h the same objective. Today's g a s o l i n e v o l a t i l i t y e v o l v e d t h r o u g h many y e a r s o f o p t i m i z a t i o n o f v e h i c l e p e r formance and e f f i c i e n t u t i l i z a t i o n o f g a s o l i n e blending stocks. Any d r a s t i c change i n t h e d i s t i l l a t i o n s p e c i f i c a t i o n s , p a r t i c u l a r l y r e d u c i n g the h i g h e r b o i l i n g components o f g a s o l i n e , would r e q u i r e w a s t e f u l changes i n r e f i n i n g schemes. I t would deny r e f i n e r s the f l e x i b i l i t y t o make optimum use o f a v a i l a b l e b l e n d i n g components and would r e q u i r e c o n v e r s i o n o f l e s s v o l a t i l e s t o c k s t o more v o l a t i l e ones w i t h a t t e n d a n t y i e l d l o s s e s and i n c r e a s e s i n crude runs and c o s t s . T h i s would be u n a d v i s e d i n the p r e s e n t energy l i m i t e d environment. P r o j e c t i n g Future

Gasoline

Demand

In o r d e r t o r e l a t e the c a r t r e n d s d i s c u s s e d i n t h i s paper t o g a s o l i n e demand, we have d e v i s e d a m a t h e m a t i c a l model i n which the c a r p o p u l a t i o n i s d e s c r i b e d by means o f parameters which a r e r e l a t e d t o f u e l economy. The c a r p o p u l a t i o n i s t r e a t e d as b e i n g composed o f f i v e c l a s s e s o f c a r s : f u l l size, i n t e r m e d i a t e , compact, d o m e s t i c sub-compact, and imported. H i s t o r i c a l d a t a a r e used t o d e t e r m i n e the f r a c t i o n o f t o t a l new c a r s a l e s i n each c l a s s i n each model y e a r , and a l s o t o c a l c u l a t e s a l e s w e i g h t e d



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averages f o r t h e parameters used t o d e s c r i b e each class. P r o j e c t i o n s o f f u t u r e s a l e s f r a c t i o n s and o f v a l u e s o f t h e parameters a r e made from t h e h i s t o r i c bases. The main d e t e r m i n a n t o f demand growth i n t h e model i s t h e growth i n annual v e h i c l e m i l e s . Changes i n t h e c a r parameters and s a l e s s h i f t s between c a r c l a s s e s cause p e r t u r b a t i o n s on t h e b a s i c demand growth c u r v e . For t h e growth c u r v e o f annual v e h i c l e m i l e s , we have used t h e p r o j e c t i o n o f t h e Department o f T r a n s p o r t a t i o n which was g i v e n i n t h e J a n u a r y 1972 r e p o r t o f t h e Committee on Motor V e h i c l e E m i s s i o n s ( 1 2 ) . This curve, i l l u s t r a t e d i n F i g u r e 5, may now be l e s s v a l i d because o f f u e l s h o r t a g e s and p r i c e i n c r e a s e s . S t i l l i t does not seem u n r e a s o n a b l e when i t i s compared w i t h census projections. I t p r o j e c t s growth i n v e h i c l e m i l e s a t an average o f 3.4% p e r y e a r t h r o u g h 1980 and 1.9% from 1980 t o 1990; w h i l e , t h e l a b o r f o r c e i s p r o j e c t e d t o i n c r e a s e a t 1.6% and t h e number o f households a t 2.2% p e r y e a r from 1970 t o 1990 (13). In any c a s e , i t w i l l s e r v e as a b a s i s on which t o a s s e s s t h e r e l a t i v e impacts o f p o t e n t i a l changes w i t h i n and among c a r classes. To c a l c u l a t e t o t a l f u e l consumption i n any y e a r , the average f u e l economy o f each model y e a r i n t h e c a r p o p u l a t i o n and t h e m i l e s t r a v e l e d by c a r s o f each model y e a r must f i r s t be o b t a i n e d . T o t a l annual miles are o b t a i n e d from F i g u r e 5, d e s c r i b e d above. The f r a c t i o n o f t h e m i l e s t r a v e l e d by each model y e a r i n t h e popul a t i o n i s t a k e n from a Department o f T r a n s p o r t a t i o n estimate o f r e l a t i v e annual miles versus c a r age(12). The average f u e l economy o f each model y e a r i s c a l c u l a t e d u s i n g the f i v e c l a s s breakdown o f c a r s a l e s i n t h a t model y e a r and t h e parameters d e s c r i b i n g each class. T h i s m a t h e m a t i c a l model was used t o p r o j e c t g a s o l i n e demand t h r o u g h 1985 and t o e x p l o r e p o t e n t i a l e f f e c t s o f e m i s s i o n s l i m i t s , c a r s i z e , and p o s s i b l e e f f i c i e n c y improvements on t h e growth i n f u t u r e g a s o l i n e demand. P o t e n t i a l E f f e c t s of Emission

Controls

Based on p u b l i s h e d i n f o r m a t i o n , p r i m a r i l y s t a t e ments by t h e a u t o m o b i l e m a n u f a c t u r e r s a t r e c e n t C o n g r e s s i o n a l h e a r i n g s (see Appendix) and on o u r own e n g i n e e r i n g assessment o f the c o n t r o l systems l i k e l y t o be used i n t h e coming y e a r s , we b e l i e v e t h a t e m i s s i o n c o n t r o l r e g u l a t i o n s w i l l l e a d t o t h e f u e l economy changes shown i n F i g u r e 6. Compared w i t h u n c o n t r o l l e d




BILLION MILES

I—REPORTED

PREDICTED-

_L

60

70

90

80 YEAR

National Academy of Sciences

Figure 5. +10

Growth in vehicle miles traveled/year

CONTROL TECHNOLOGY INTRODUCED: -ENGINE MODIFICATIONS -EXHAUST GAS RECIRCULATION

FUEL ECONOMY CHANGE, ~

J—OXIDATION CATALYSTS 1

ΝΟχ CONTROL METHOD UNCERTAIN

0

% -20

-30 EMISSION HC LIMITS, CO g/mi(1975 CVS) NO

1967

x

1974

1973 ~"\/ 3.0 28 3.1

1975

1975

1977

1978

1.5 15 3.1

.9 9 2.0

.41 3.4 2.0

.41 3.4 .4

1

Figure 6. Effect of emission standards on fuel economy



2.

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AND KOEHL

Automotive Trends and Emissions Reguhtions

27

c a r s o f 1967, we see a 15% l o s s i n f u e l economy i n t h e 1973 models. Some improvement appears t o have o c c u r r e d i n 1974, and i n 1975 models o u t s i d e o f C a l i f o r n i a , we e x p e c t a 3% improvement o v e r 1974. In F i g u r e 6, t h e d a t e s a s s i g n e d t o t h e s t a n d a r d s shown beyond 1975 a r e t h e e a r l i e s t model y e a r s i n which we would e x p e c t them t o a p p l y i n view o f r e c e n t a c t i o n s i n Congress (22). The l o s s through 1973 i s a t t r i b u t e d t o changes i n spark t i m i n g and a i r - f u e l r a t i o , and t o i n t r o d u c t i o n o f exhaust gas r e c i r c u l a t i o n , changes made t o c o n t r o l p o l l u t a n t f o r m a t i o n i n t h e e n g i n e , as w e l l as t o r e d u c t i o n o f compression r a t i o i n a n t i c i p a t i o n o f 91 octane unleaded g a s o l i n e . With t h e i n t r o d u c t i o n o f c a t a l y s t s i n t h e exhaust stream t o c o n t r o l h y d r o c a r b o n and carbon monoxide e m i s s i o n s from c a r s meeting t h e 1975 4 9 - s t a t e s i n t e r i m s t a n d a r d s , engine c a l i b r a t i o n s can be p a r t i a l l y r e s t o r e d t o more e f f i c i e n t s e t t i n g s t o r e g a i n a s m a l l p a r t o f t h e f u e l economy l o s t because of emission c o n t r o l s . However, beyond t h e s e 1975 l i m i t s , f u e l economy l o s s e s w i l l a g a i n i n c r e a s e and c o u l d r i s e t o 30% i f t h e most s t r i n g e n t s t a n d a r d s s e t by t h e C l e a n A i r A c t o f 1970 must be met. Our p r o j e c t i o n o f d i m i n i s h i n g f u e l economy a t t h e more s t r i n g e n t e m i s s i o n l e v e l s beyond 1975 p a r a l l e l s p u b l i s h e d e s t i m a t e s by G e n e r a l Motors C o r p o r a t i o n and F o r d Motor Company (see A p p e n d i x ) . With t h e 1975 i n t e r i m C a l i f o r n i a s t a n d a r d s and the s t a n d a r d s i n d i c a t e d f o r 1977, we e x p e c t t h e f u e l economy l o s s e s r e l a t i v e t o u n c o n t r o l l e d c a r s t o be 14 and 18%, r e s p e c t i v e l y . These a r e a s s o c i a t e d w i t h r e t a r d e d spark t i m i n g , r i c h e r a i r - f u e l r a t i o s , and exhaust gas r e c i r c u l a t i o n r e q u i r e d p r i m a r i l y f o r N 0 control. Least c e r t a i n o f attainment are the s t a t u t o r y l i m i t s o f 0.4 g/mi. f o r h y d r o c a r b o n s , 3.4 f o r carbon monoxide, and 0.4 f o r o x i d e s o f n i t r o g e n u l t i m a t e l y r e q u i r e d by t h e C l e a n A i r A c t . Because adequate t e c h n o l o g y has n o t y e t been i d e n t i f i e d f o r meeting t h e s e s t a n d a r d s , o u r e s t i m a t e s o f t h e f u e l economy p e n a l t y ranges from 20% t o as much as 30% r e l a t i v e t o 1967 c a r s . Our o p t i m i s t i c p r o j e c t i o n assumes d e v e l o p ment o f a n i t r i c o x i d e r e d u c t i o n c a t a l y s t which cannot p r e s e n t l y be r e g a r d e d as t e c h n i c a l l y f e a s i b l e i n t h e context o f the r e g u l a t i o n s ; while our p e s s i m i s t i c p r o j e c t i o n assumes N 0 c o n t r o l c o u l d be a c h i e v e d through t h e maximum degree o f exhaust gas r e c i r c u l a t i o n t h a t i s c o n s i s t e n t w i t h engine o p e r a t i o n . Some auto i n d u s t r y p r o j e c t i o n s f o r the n i t r i c oxide r e d u c t i o n c a t a l y s t are c l o s e r t o our p e s s i m i s t i c estimate. X

X



28


In t h i s assessment, we have t r i e d t o i s o l a t e t h e e f f e c t o f e n g i n e changes made p r i m a r i l y f o r e m i s s i o n control. Compression r a t i o r e d u c t i o n i s i n c l u d e d among t h e s e changes. We have a l s o endeavored t o compare systems on a c o n s t a n t performance b a s i s . In e v a l u a t i n g v e h i c l e t e s t d a t a , one must be c a r e f u l t o s e p a r a t e e m i s s i o n c o n t r o l e f f e c t s from c o u n t e r a c t i n g e f f e c t s o f o t h e r changes, such as r e d u c e d a c c e l e r a t i o n performance, h i g h energy i g n i t i o n systems, improved carburetors, r a d i a l t i r e s , or s h i f t s to smaller cars. These changes would y i e l d f u e l economy improvements r e g a r d l e s s o f t h e e m i s s i o n c o n t r o l system chosen. To compare the p o t e n t i a l e f f e c t s o f the e m i s s i o n l i m i t s shown i n F i g u r e 6, we have used the c o r r e sponding f u e l economy changes i n our math model. The new c a r s a l e s mix ( f u l l s i z e , i n t e r m e d i a t e , compact, sub-compact, and imported) i n f u t u r e y e a r s was assumed t o be t h e same as i n 1973, w h i l e the parameters d e s c r i b i n g t h e new c a r s i n each f u t u r e y e a r were a l s o held at current values. A n n u a l v e h i c l e m i l e s were a l l o w e d t o i n c r e a s e as p r o j e c t e d i n F i g u r e 5. The p r o j e c t e d growth i n g a s o l i n e demand t h r o u g h 1985 a t each e m i s s i o n l e v e l i s t r a c e d i n F i g u r e 7. For a l l o f t h e s e p r o j e c t i o n s , the g a s o l i n e i s assumed t o be 91 o c t a n e u n l e a d e d g a s o l i n e . The f u e l economy d e b i t s a t t r i b u t e d t o each e m i s s i o n l e v e l were h e l d c o n s t a n t t h r o u g h the p e r i o d o f the p r o j e c t i o n s i n F i g u r e 7. E v o l u t i o n a r y improvements can r e a s o n a b l y be e x p e c t e d t h a t would reduce the f u e l economy d e b i t s as m a n u f a c t u r i n g and s e r v i c e e x p e r i e n c e grows; however, such improvements ought t o be a p p l i c a b l e i n some degree a t a l l o f t h e e m i s s i o n l e v e l s so t h a t on a r e l a t i v e b a s i s , our g a s o l i n e demand p r o j e c t i o n would not change s i g n i f i c a n t l y . The g a s o l i n e demands p r o j e c t e d i n F i g u r e 7 f o r t h e y e a r 1985 a r e summarized i n the t a b l e below a l o n g w i t h t h e p e r c e n t a g e changes i n 1985 from a base case i n which 1973/74 e m i s s i o n s t a n d a r d s a r e assumed t o a p p l y t o a l l model y e a r s t h r o u g h 1985. In computing the demand f o r any y e a r , each e m i s s i o n l i m i t i s a p p l i e d from i t s y e a r o f i n t r o d u c t i o n u n t i l i t i s superseded by a subsequent, more r e s t r i c t i v e s t a n d a r d .


2.

C L E W E L L AND


Emission


KOEHL

Limits

Year o f Introduction

HC,

1973

3,

CO,

Ν0 * χ

28,

49-States

1.5,

1975

California

.9,

1977

Proposed

.41,

3.4,

2

1978

Statutory

.41,

3.4,

.4

15, 9,

1985 P r o j e c t i o n o f 91 Octane Unleaded Gasoline Required f o r Automobiles Change from billion Base, % gal.

3.1

1975

3.1

2

to *g/mi. on

1975

CVS

29

121

Base

117

- 3

122

+ 1

128

+ β

132 150

to

+ 9 +24

test basis.

F o r p e r s p e c t i v e , the maximum demand i n c r e m e n t w i t h the most s e v e r e e m i s s i o n s l i m i t s (29 b i l l i o n g a l l o n s a n n u a l l y o r 1.9 m i l l i o n b a r r e l s p e r day) i s g r e a t e r than the g a s o l i n e s h o r t f a l l o f 1.4 m i l l i o n b a r r e l s per day a n t i c i p a t e d d u r i n g the embargo on shipment o f A r a b i a n o i l t o the U n i t e d S t a t e s i n the W i n t e r o f 1973-1974 (3). While the f u e l s a v i n g p r o j e c t e d f o r the 1975 system r e l a t i v e t o p r e s e n t c o n t r o l s may be l e s s t h a n p r o j e c t e d by o t h e r s , the i m p o r t a n t p o i n t i s t h a t moving t o more s t r i n g e n t e m i s s i o n l i m i t s than the 1975 i n t e r i m l i m i t s w i l l r e q u i r e s u b s t a n t i a l l y more g a s o l i n e . T h e r e f o r e , i t seems r e a s o n a b l e t o s e t e m i s s i o n s t a n d a r d s a t l e v e l s t h a t are j u s t i f i a b l e i n terms o f a t t a i n i n g d e s i r e d ambient a i r q u a l i t y l e v e l s , n o t a t a r b i t r a r y l e v e l s t h a t a r e unduly r e s t r i c t i v e and demanding o f energy. Prospects

f o r Moderating Gasoline

Demand Growth

Even w i t h the lowest demand growth c u r v e s i n F i g u r e 7, which are based on new c a r p o p u l a t i o n s as i n 1973, we p r o j e c t an i n c r e a s e i n g a s o l i n e demand f o r a u t o m o b i l e s o f a l m o s t 50% from 1973 t o 1985. This can be compared w i t h the 50% growth from 1970 t o 1985 p r o j e c t e d by the T r a n s p o r t a t i o n Energy Panel(15) and w i t h growth i n t o t a l energy r e q u i r e m e n t s p r o j e c t e d by others. F o r example, the N a t i o n a l P e t r o l e u m C o u n c i l p r o j e c t e d growth o f 70 t o 90% from 1970 to 1985 (14) and the Bureau o f Mines p r o j e c t e d about 70% over a similar period(16).



30

AUTOMOTIVE

EMISSIONS

CONTROL

What are the p r o s p e c t s f o r s u b s t a n t i a l l y r e d u c i n g , o r even a v o i d i n g , t h i s p r o j e c t e d 50% growth i n g a s o l i n e demand f o r a u t o m o b i l e s ? With the t e c h n o l o g y a v a i l a b l e now, two m o d e r a t i n g t r e n d s are o b v i o u s p o s s i b i l i t i e s , and b o t h c o u l d be seen t o be t a k i n g some e f f e c t i n r e c e n t months. One i s r e d u c t i o n i n v e h i c l e m i l e s t r a v e l e d , the o t h e r i s r e p l a c e m e n t of l a r g e c a r s w i t h s m a l l e r ones. In the l o n g e r term, improvements i n automotive t e c h n o l o g y can be e x p e c t e d t o p r o v i d e a d d i t i o n a l f u e l economy b e n e f i t s . These w i l l come through improved engine and d r i v e t r a i n e f f i c i e n c i e s , l i g h t e r weight components, improved e f f i c i e n c y i n power a c c e s s o r i e s , and improvements i n body aerodynamics. We w i l l e x p l o r e a few o f t h e s e o p t i o n s . Reduced V e h i c l e M i l e s . In r e c e n t months we have seen a f o r c e d r e d u c t i o n i n c a r usage because t h e r e has not been enough g a s o l i n e a v a i l a b l e t o l e t us d r i v e as much as we would l i k e . People are a d j u s t i n g to l i f e w i t h l e s s g a s o l i n e and l e s s c a r t r a v e l , but not w i t h o u t i n c o n v e n i e n c e and even h a r d s h i p . Since even r e c r e a t i o n a l d r i v i n g i s i m p o r t a n t t o the p e r s o n accustomed t o i t , and e s p e c i a l l y t o the p e r s o n whose l i v e l i h o o d depends on i t , c a r usage can be e x p e c t e d to r e t u r n t o more normal l e v e l s w i t h i n c r e a s i n g s u p p l i e s o f g a s o l i n e now becoming a v a i l a b l e . In the l o n g e r term g a s o l i n e p r i c e s w i l l i n f l u e n c e p e o p l e t o s w i t c h t o more e f f i c i e n t c a r s t h a t w i l l e n a b l e them to d r i v e the r e q u i r e d m i l e s . Consequently, there i s u n l i k e l y t o be a r e d u c t i o n i n a n n u a l c a r m i l e s which, by i t s e l f , would have a s u b s t a n t i a l e f f e c t i n r e d u c i n g g a s o l i n e demand. O p p o r t u n i t i e s f o r some m i l e a g e r e d u c t i o n s appear to e x i s t i n i n c r e a s e d c a r p o o l i n g and the use o f p u b l i c t r a n s p o r t a t i o n . The Department o f T r a n s p o r t a t i o n e s t i m a t e s t h a t p o t e n t i a l s a v i n g s from i n c r e a s e d c a r p o o l i n g , and i n c r e a s e d usage o f urban t r a n s i t , and i n t e r c i t y bus and r a i l would be o n l y 1 . 2 , 1.0 and 0.5%, r e s p e c t i v e l y , of n a t i o n a l t r a n s p o r t a t i o n f u e l requirements after five years(3). These s a v i n g s could increase to 8 . 3 , 1.7, and 1 . 3 % , r e s p e c t i v e l y , i n 15 y e a r s Q ) . S h i f t to Smaller Cars. U s i n g our math model, we have e s t i m a t e d the p o t e n t i a l 1985 g a s o l i n e demand w i t h a s h i f t o f new c a r s a l e s from l a r g e c a r s t o s m a l l e r ones as compared t o m a i n t a i n i n g the 1973 new c a r s a l e s mix. The base 1973 new c a r s a l e s mix and a f u t u r e new c a r mix a c h i e v e d w i t h i n c r e a s i n g p e n e t r a t i o n o f s m a l l c a r s are shown i n F i g u r e 8 i n terms o f the c a r c l a s s e s



C L E W E L L AND K O E H L


ANNUAL DEMAND, BILLION GALLONS

1970

1975

1980

1985

YEAR Figure 7. Gasoline demand projections for automobiles —effect of emission standards

50 40 30 20 PERCENT OF NEW CAR

10

SMALL CARS

SUB-COMPACT - (U.S. & IMPORTS)

lr*—" "

'Ί973"ΜΙΧ-[--ΐ

COMPACT 1970

FUTURE MIX=j

1 1 1 11975 1 1 11 I1980 1 1 1 1 1985 1 YEAR

Figure 8. Hypothetical future new car sales mixes for projecting gasoline demand



32

AUTOMOTIVE

EMISSIONS

CONTROL

used i n our model. F i g u r e 9 shows the g a s o l i n e demand growth c u r v e s c a l c u l a t e d f o r the two c a s e s . I t can be seen t h a t i f the p o s t u l a t e d s h i f t t o s m a l l e r c a r s were a c h i e v e d , g a s o l i n e consumption by a u t o m o b i l e s would i n c r e a s e o n l y about 37% o v e r t h a t c a l c u l a t e d f o r 1973 v e r s u s 51% i f the 1973 new c a r s a l e s mix were maintained. T h i s r e p r e s e n t s a p o t e n t i a l s a v i n g i n 1985 o f 9%. F o r t h i s comparison, 1973/74 e m i s s i o n c o n t r o l s were assumed t o be i n e f f e c t t h r o u g h 1985. With 1975 e m i s s i o n c o n t r o l s , the s a v i n g would be about the same, but the g a s o l i n e demand o f the p o s t u l a t e d f u t u r e mix would be about 3% lower t h a n shown i n F i g u r e 9. The f u l l b e n e f i t o f t h e p o s t u l a t e d s h i f t t o s m a l l e r c a r s would n o t be seen u n t i l 1990 o r l a t e r when n e a r l y a l l pre-1980 c a r s would be r e p l a c e d . F i g u r e 9 a l s o shows the p r o j e c t e d f u e l s a v i n g s a s s o c i a t e d w i t h the s h i f t i n s a l e s mix t h a t o c c u r r e d from 1970 t o 1973 as the P i n t o , the Vega, and the G r e m l i n were i n t r o d u c e d . With the 1970 new c a r mix a d j u s t e d to the same e m i s s i o n l e v e l s as the 1973 mix, t h i s would r e p r e s e n t an e s t i m a t e d s a v i n g o f 6% i n 1985. Our p o s t u l a t e d r e d u c t i o n o f the b i g c a r segment ( f u l l s i z e and i n t e r m e d i a t e ) o f the new c a r market from about 58% i n 1973 t o 40% by 1980 does n o t seem u n r e a s o n a b l e i n l i g h t o f the r e d u c t i o n from 68% i n 1970 t h a t has a l r e a d y o c c u r r e d . According to recent news s t o r i e s , F o r d has i n d i c a t e d t h a t s m a l l c a r s c o u l d amount t o 50 t o 60% o f the market as soon as September, 1974 (17); and G e n e r a l Motors has i n d i c a t e d t h a t s m a l l c a r p r o d u c t i o n c a p a b i l i t y i n 1975 would be 30% g r e a t e r than i n 1974 and c o u l d be d o u b l e d i n 1976, i f necessary(18). Improved V e h i c l e E f f i c i e n c y . Improvements i n e n g i n e and d r i v e t r a i n e f f i c i e n c y ( e x c l u d i n g i n c r e a s e d compression r a t i o which w i l l be d i s c u s s e d l a t e r ) c o u p l e d w i t h weight r e d u c t i o n i n c a r components and improved aerodynamics might r e a s o n a b l y be e x p e c t e d t o a f f o r d a f u r t h e r 10 t o 15% i n c r e a s e i n f u e l economy when f u l l y implemented. R a d i a l t i r e s and improved e f f i c i e n c y i n power a c c e s s o r i e s c o u l d a l s o c o n t r i b u t e to t h i s s a v i n g . Assuming t h a t t h e s e improvements l e a d to 10% b e t t e r f u e l economy i n 1980 models and 15% i n 1985 models, we p r o j e c t a p o t e n t i a l g a s o l i n e s a v i n g i n 1985 o f 11%. T h i s e s t i m a t e i s based on 1973/74 e m i s s i o n l e v e l s and t h e s h i f t t o s m a l l e r c a r s p o s t u l a t e d above. As i n the case o f the s h i f t t o s m a l l e r c a r s , the f u l l 15% b e n e f i t o f t h e p o s t u l a t e d improvements would n o t be r e a l i z e d u n t i l a l l l e s s e f f i c i e n t c a r s are r e p l a c e d .



2.

CLEWELL AND KOEHL


33

Our p o s t u l a t e d 10 t o 15% e f f i c i e n c y improvement i s a l s o c o r r o b o r a t e d by F o r d and G e n e r a l Motors p r e d i c t i o n s t h a t the minimum f u e l economy o f f u t u r e s t a n d a r d s i z e c a r s i s l i k e l y t o be 13 t o 15 mpg(18); as c o n t r a s t e d t o 11.5 mpg and l e s s f o r the average 1970 t o 1974 f u l l s i z e c a r s i n our model. As s t a t e d e a r l i e r , we e s t i m a t e t h a t about h a l f o f the f u e l economy l o s s a s s o c i a t e d w i t h e m i s s i o n c o n t r o l s (7 o f the 15% f o r 1973 systems) i s due t o the r e d u c t i o n i n compression r a t i o t h a t was made t o accommodate 91 o c t a n e u n l e a d e d g a s o l i n e . T h i s energy l o s s c o u l d be r e c o v e r e d i n p a r t by use o f h i g h e r octane unleaded g a s o l i n e i n engines of i n c r e a s e d compression r a t i o . I t c o u l d be r e c o v e r e d i n f u l l , and even beyond, i f the c u r r e n t e m i s s i o n s t a n d a r d s were r e t a i n e d , o r i f l e a d t o l e r a n t low e m i s s i o n e n g i n e s o r e m i s s i o n c o n t r o l systems were d e v e l o p e d t o meet more s t r i n g e n t s t a n d a r d s . Then l e a d e d g a s o l i n e c o u l d c o n t i n u e t o be used, and compression r a t i o c o u l d be increased. Of c o u r s e , the r e c e n t l y p u b l i s h e d r e g u l a t i o n s ( 1 1 ) r e q u i r i n g a phase-down o f the l e a d c o n t e n t o f g a s o l i n e would have t o be r e v o k e d t o a l l o w the f u l l f u e l s a v i n g p o t e n t i a l o f l e a d t o be r e a l i z e d . If a i r quality s t a n d a r d s f o r l e a d p a r t i c u l a t e s were t h e n e s t a b l i s h e d , d e v i c e s t o remove l e a d from v e h i c l e e x h a u s t c o u l d be a p p l i e d t o meet them. S e v e r a l companies have r e p o r t e d v e r y marked p r o g r e s s i n the development o f t h e s e d e v i c e s which shows t h a t t h e y are f e a s i b l e f o r 80% removal o f l e a d p a r t i c u l a t e s from e x h a u s t ( 1 9 , 2 0 ) . Our s t u d i e s i n d i c a t e t h a t adding 2.5 g o f l e a d p e r g a l l o n t o the 91 o c t a n e unleaded g a s o l i n e t h a t w i l l soon be a v a i l a b l e because o f c u r r e n t r e g u l a t i o n s (10, 11) would p e r m i t an o c t a n e number i n c r e a s e t o 98 and an engine e f f i c i e n c y i n c r e a s e o f up t o 13%. A t the 1973/74 e m i s s i o n s l e v e l w i t h the 1973 new c a r s a l e s mix, the 1985 g a s o l i n e demand o f 121 b i l l i o n g a l l o n s c o u l d be reduced by up t o 16 b i l l i o n g a l l o n s , i f the f u l l f u e l s a v i n g p o t e n t i a l o f l e a d e d g a s o l i n e were e x p l o i t e d by t h a t time. I n our p o s t u l a t e d s c e n a r i o o f i n c r e a s i n g penet r a t i o n o f s m a l l e r c a r s a l o n g w i t h o t h e r f u e l economy improvements, the added e f f e c t o f l e a d i n m o d e r a t i n g the growth i n g a s o l i n e demand c o u l d be as shown i n F i g u r e 10. F o r t h i s p r o j e c t i o n , 1973/74 e m i s s i o n s t a n d a r d s were assumed t o a p p l y a l o n g w i t h the 10 t o 15% e f f i c i e n c y improvement d i s c u s s e d above. The compression r a t i o i n c r e a s e which would be e q u i v a l e n t t o a 13% i n c r e a s e i n e f f i c i e n c y was assumed t o be phased i n from 1976 through 1979. The r e s u l t a n t s a v i n g




130 120

ANNUAL DEMAND, BILLION GALLONS

110

AT 1973/74 EMISSION LEVELS . BASE - 1973 NEW CAR MIXFUTURE NEW CAR MIXENGINES! VEHICLE IMPROVEMENTS IN FUTURE MIX

. ALL WITH 91 OCTANE UNLEADED GASOLINE 90 h

100

80 70

1970

» INCREASED COMPRESSION RATIO AND 98 OCTANE LEADED GASOLINE • 1980 NEW CAR MIX 1980

1975

1985

YEAR

Figure 10. Gasoline demand projections for automobiles— effect of efficiency improvement


2.

C L E W E L L AND KOEHL


35

i n 1985 c o u l d be 10% b u t t h e f u l l b e n e f i t would n o t be r e a l i z e d u n t i l sometime l a t e r when a l l lower compression r a t i o c a r s c o u l d be r e p l a c e d . Summary Based on p a s t t r e n d s , g a s o l i n e demand has been p r o j e c t e d t o i n c r e a s e about 50% from 1973 t o 1985 a t c u r r e n t o r 1975 4 9 - s t a t e s e m i s s i o n l e v e l s , and maybe as much as 90% i f t h e s t a t u t o r y NO e m i s s i o n s t a n d a r d o f 0.4 g/mi. i s r e t a i n e d and can be approached o n l y by EGR. These p r o j e c t i o n s assume t h a t t h e mix o f v e h i c l e types on t h e r o a d w i l l remain t h e same as i n 1973 and t h a t f u t u r e c a r usage w i l l grow as p r o j e c t e d before the current gasoline shortage. However, t h i s r a t e o f i n c r e a s e i n demand i s n o t i n e v i t a b l e . Forces are a l r e a d y a t work t h a t c o u l d moderate i t . The p r e s e n t l y e v i d e n t t r e n d toward s m a l l e r c a r s , i f i t c o n t i n u e s , a l o n g w i t h development o f t e c h n o l o g y t o implement t h e improvements i n v e h i c l e e f f i c i e n c y t h a t appear f e a s i b l e c o u l d s u b s t a n t i a l l y reduce t h e r a t e o f growth i n g a s o l i n e demand. Choosing v e h i c l e emiss i o n s t a n d a r d s w i t h due c o n c e r n f o r a t t a i n m e n t o f a i r q u a l i t y s t a n d a r d s and c o n s e r v a t i o n o f f u e l s h o u l d p r e v e n t unnecessary i n c r e a s e s i n demand. P o t e n t i a l 1985 g a s o l i n e s a v i n g s p r o j e c t e d i n t h i s paper a r e summarized below. I f i t were p o s s i b l e t o implement a l l o f them, a u t o m o b i l e s meeting the 1973/74 e m i s s i o n s t a n d a r d s and u s i n g l e a d e d g a s o l i n e might r e q u i r e o n l y 10% more g a s o l i n e i n 1985 t h a n c a l c u l a t e d f o r 1973; w h i l e t h o s e meeting 1975 i n t e r i m 4 9 - s t a t e s s t a n d a r d s w i t h unleaded g a s o l i n e might r e q u i r e o n l y 19% more. A t more s t r i n g e n t s t a n d a r d s , t h e growth would be g r e a t e r .


x


36


Emission Level HC, CO, NO , g/mi.


x

1973/74 3,28,3.1

1975 49-States 1.5,15,3.1

1985 Demand w i t h Uncons t r a i n e d Growth, b i l . g a l . I n c r e a s e o v e r 1973 Demand o f 80 b i l . g a l .

121

117

51%

46%

1985 S a v i n g w i t h S h i f t t o Smaller Cars, b i l . g a l .

11.3

10.8

1985 S a v i n g w i t h Improved Engine and D r i v e T r a i n E f f i c i e n c y and V e h i c l e Weight R e d u c t i o n , b i l . g a l .

12.0

11.3

1985 S a v i n g w i t h Leaded G a s o l i n e and I n c r e a s e d Compression R a t i o , b i l . gal.

9.5

1985 Demand i f a l l S a v i n g s are R e a l i z e d , b i l . g a l . Increase over C a l c u l a t e d 1973 Demand o f 80 b i l . gal.

Not a v a i l a b l e i f catalysts a r e used

88.2

94.9

10%

19%

Our o p t i m i s t i c p r o j e c t i o n t h a t the 1985 g a s o l i n e demand f o r automobiles a l o n e c o u l d be h e l d t o 10 t o 20% more than i n 1973 i s dependent, as d i s c u s s e d above, on changes i n promulgated e m i s s i o n s r e g u l a t i o n s , c o n t i n u a t i o n o f t h e t r e n d t o s m a l l c a r s , and o t h e r improvements i n f u e l economy. I t would r e p r e s e n t a s u b s t a n t i a l p o t e n t i a l g a s o l i n e s a v i n g and would be e q u i v a l e n t i n energy t o about two m i l l i o n b a r r e l s p e r day l e s s crude o i l t h a n p r o j e c t e d by t h e uncons t r a i n e d demand c u r v e . Compared t o t o t a l p r o j e c t e d 1985 p e t r o l e u m r e q u i r e m e n t s o f 25 m i l l i o n b a r r e l s p e r y ( 1 4 , 2 1 ) , i t r e p r e s e n t s a s a v i n g o f about 8% and r e l a t i v e t o t o t a l 1985 energy p r o j e c t i o n s o f 58 m i l l i o n b a r r e l s p e r day o i l e q u i v a l e n t ( 2 1 ) , a s a v i n g o f about 3%. These l a s t comparisons show t h a t w h i l e t h e p r o j e c t e d g a s o l i n e s a v i n g c o u l d be v e r y s u b s t a n t i a l i n a b s o l u t e terms, i t would s t i l l be a r e l a t i v e l y s m a l l s a v i n g i n t o t a l energy r e q u i r e m e n t s . Therefore, w h i l e h i g h l y d e s i r a b l e , i t s h o u l d n o t be viewed as t h e complete answer t o our n a t i o n a l energy problems. Cons e r v a t i o n i n o t h e r consuming s e c t o r s i s a l s o needed. d a


2.

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37


I n a d o p t i n g energy c o n s e r v a t i o n p o l i c i e s f o r t h e f u t u r e , we s h o u l d remember t h a t l i q u i d h y d r o c a r b o n f u e l s are i d e a l l y s u i t e d f o r t r a n s p o r t a t i o n a p p l i cations. C u r r e n t s h o r t a g e s a r e due n o t o n l y t o r i s i n g demand f o r a l l f u e l s b u t a l s o t o s u b s t i t u t i o n o f p e t r o l e u m f u e l s f o r h i g h e r s u l f u r c o a l and f o r s c a r c e gas. To c o n s e r v e p e t r o l e u m and m i n i m i z e t h e economic and p o l i t i c a l c o s t s o f i m p o r t i n g o i l , we s h o u l d t r y not o n l y t o moderate t h e r i s i n g demand f o r f u e l s b u t a l s o t o r e s e r v e l i q u i d p e t r o l e u m f u e l s f o r premium a p p l i c a t i o n s such as t r a n s p o r t a t i o n w h i l e f i n d i n g e n v i r o n m e n t a l l y a c c e p t a b l e ways t o use d o m e s t i c c o a l and n u c l e a r energy i n a p p l i c a t i o n s such as power generation that are adaptable to a v a r i e t y o f f u e l s . Acknowledgment We g r a t e f u l l y acknowledge t h e a b l e a s s i s t a n c e o f Drs. C. R. Morgan and M. Ohta o f M o b i l Research and Development C o r p o r a t i o n who d e v e l o p e d t h e m a t h e m a t i c a l model used i n t h i s s t u d y .

Literature Cited 1.

"Energy Statistics, A Supplement t o t h e Summary of National Transportation Statistics," U. S. Department o f T r a n s p o r t a t i o n , Report No. DOT-TSC-OST-73-34, September, 1973.

2.

Annual Statistical Reviews, U. S. P e t r o l e u m Industry Statistics, American P e t r o l e u m Institute; and, 1972 N a t i o n a l P e t r o l e u m News Factbook I s s u e , and earlier issues.

3.

W h i t f o r d , R. K. and H a s s l e r , F. L., "Some T r a n s p o r t a t i o n Energy O p t i o n s and T r a d e - O f f s : A F e d e r a l View," p r e s e n t e d a t California Institute o f Technology, January 8, 1974.

4.

Highway Statistics - 1960 through 1970 i s s u e s , U. S. Department o f T r a n s p o r t a t i o n , F e d e r a l Highway A d m i n i s t r a t i o n , Bureau o f Public Roads.

5.

C a l c u l a t e d u s i n g s h i p p i n g w e i g h t d a t a from Automotive I n d u s t r i e s Statistical I s s u e , 1960 t h r o u g h 1972, and M o b i l e s t i m a t e o f c a r popudistribution.

6.

B r i e f Passenger C a r Data, E t h y l Corp., 1960 t h r o u g h 1970; 1971 and 1972 N a t i o n a l P e t r o l e u m News Factbook I s s u e .

lation



38

7.

Ward's Automotive Ward's Automotive

Year Book, 1960 through 1970; R e p o r t s , September 25, 1972.

8.

Ward's Automotive

R e p o r t s , F e b r u a r y 26,

9.

M i n e r a l I n d u s t r i e s S u r v e y s , Motor G a s o l i n e s , U. S. Department o f the Interior, Bureau o f Mines.

1973.

10. R e g u l a t i o n o f F u e l s and F u e l A d d i t i v e s , F e d e r a l R e g i s t e r , January 10, 1973, p. 1254.


11. R e g u l a t i o n o f F u e l s and F u e l A d d i t i v e s , F e d e r a l R e g i s t e r , December 6, 1973, p. 33734. 12. Semiannual Report by the Committee on Motor V e h i c l e E m i s s i o n s , N a t i o n a l Academy o f S c i e n c e s t o the E n v i r o n m e n t a l P r o t e c t i o n Agency, January 1, 1972. 13. A Guide t o Consumer Markets 1973/74, Report No. 607, The Conference Board, I n c . , New York, Ν. Υ., 1973. 14. U. S. Energy O u t l o o k , A Summary R e p o r t o f the N a t i o n a l P e t r o l e u m C o u n c i l , December 1972. 15.

"Research and Development O p p o r t u n i t i e s for Improved T r a n s p o r t a t i o n Energy Usage - Summary T e c h n i c a l Report o f the T r a n s p o r t a t i o n Energy R&D Goals P a n e l , " U. S. Department o f T r a n s p o r tation, September 1972.

16. The P o t e n t i a l f o r Energy C o n s e r v a t i o n : A Study, E x e c u t i v e Office o f the P r e s i d e n t , o f Emergency P r e p a r e d n e s s , October 1972. 17. Automotive

News, January

21, 1974,

p.

18. Automotive

I n d u s t r i e s , March 1, 1974,

Staff Office

1. p. 17 and

18.

19. C a n t w e l l , Ε. Ν., J a c o b s , Ε. I . , Kunz, W. G. and Liberi, V. Ε . , S o c i e t y o f Automotive E n g i n e e r s , N a t i o n a l Automobile E n g i n e e r i n g M e e t i n g , D e t r o i t , M i c h i g a n , May 1972, Paper 720672. 20. H i r s c h l e r , D. Α., Adams, W. E. and Marsee, F. J., N a t i o n a l Petroleum Refiners A s s o c i a t i o n Annual M e e t i n g , San A n t o n i o , Texas, April 1-3, 1973, Paper AM-73-15.


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21. DuPree, W. G., " U n i t e d S t a t e s Energy Requirements t o the Year 2000," American S o c i e t y o f M e c h a n i c a l E n g i n e e r s , p r e s e n t e d a t I n t e r s o c i e t y Conference on T r a n s p o r t a t i o n , Denver, C o l o r a d o , September 1973, Paper No. 73-ICT-105. 22.

S2589 (Energy Emergency A c t ) Conference December 1973.

Report,


APPENDIX E f f e c t o f E m i s s i o n C o n t r o l s on F u e l Economy In F i g u r e A - l , our assessment o f t h e f u e l economy l o s s e s a s s o c i a t e d w i t h e m i s s i o n c o n t r o l s i s compared w i t h p u b l i s h e d e s t i m a t e s from s e v e r a l s o u r c e s . The F o r d r e p o r t o f a 13% l o s s i n c i t y - s u b u r b a n f u e l economy i n 1973 r e l a t i v e t o u n c o n t r o l l e d c a r s i s based on a n a l y s i s o f a l a r g e number o f c a r s i n a f l e e t whose c o m p o s i t i o n was c o n s t a n t through the period (A-l). E f f e c t s o f e m i s s i o n c o n t r o l s were s e p a r a t e d from e f f e c t s o f changes i n v e h i c l e weight, engine d i s p l a c e m e n t , r e a r a x l e r a t i o , and a c c e s s o r y equipment. P r o j e c t i o n s f o r the f u t u r e y e a r s are made from t h i s 1973 base (A-2). Note t h a t F o r d e x p e c t s a 3% g a i n from 1974 t o 1975 i n t e r i m 4 9 - s t a t e s s t a n d a r d s i n c a t a l y s t - e q u i p p e d v e h i c l e s b u t a 5% l o s s i n v e h i c l e s without c a t a l y s t s . The C h r y s l e r e s t i m a t e f o r 1973 i s based on an a n a l y s i s o f a t y p i c a l i n t e r m e d i a t e s i z e c a r (A-3), w h i l e t h o s e f o r 1974 and 1975 are based on t e s t i m o n y t o the Senate Subcommittee on P u b l i c Works (A-4). G e n e r a l M o t o r s statement t o the Senate Committee on P u b l i c Works i n d i c a t e s a 15% l o s s due t o e m i s s i o n c o n t r o l s i n 1973 r e l a t i v e t o u n c o n t r o l l e d c a r s , a f t e r weight e f f e c t s are s u b t r a c t e d (A-5). From 1973 t o 1974, i t shows a 1% g a i n based on the average o f t y p i c a l h i g h volume models [the p o i n t (x) i n F i g u r e A - l ] , but a 1% l o s s based on a s a l e s weighted average a f t e r c o r r e c t i n g f o r v e h i c l e weight i n c r e a s e s . In g o i n g from 1974 t o 1975 i n t e r i m 4 9 - s t a t e s s t a n d a r d s , GM e s t i m a t e s range from 10% t o about 20%. The GM statement shows a 13% improvement i n c i t y t r a f f i c economy on an average b a s i s a t an e q u i v a l e n t v e h i c l e weight. In o r a l t e s t i m o n y GM i n d i c a t e d t h a t the improvement a t t r i b u t a b l e t o the e m i s s i o n c o n t r o l s a l o n e was o n l y 10% (A-6). In c o n t r o l l e d t e s t s w i t h one l a r g e 1



40


Figure A-l.

Effect of emission standards on fuel economy



2.

C L ÉW E L L A N D K O E H L

Automotive Trends and Emissions Régulations

41

c a r , a 21% improvement was i n d i c a t e d i n c i t y f u e l economy r e l a t i v e t o an average f o r new 1973 p r o d u c t i o n models o f t h i s c a r ; f o r highway economy t h e improvement was o n l y 6% (A-5). I n F i g u r e A - l , we have p l o t t e d b o t h the 10% e s t i m a t e and t h e one-car r e s u l t s t o e s t a b l i s h the range o f GM e s t i m a t e s f o r the 1975 4 9 - s t a t e s standard. F o r more s e v e r e s t a n d a r d s than t h e 1975 4 9 - s t a t e s s t a n d a r d , t h e one-car r e s u l t s show t h e downward t r e n d i n f u e l economy. The DuPont assessment (A-7) f o r 1973 i s based on measurements w i t h a c o n s t a n t f l e e t o f s i x p r o d u c t i o n cars. I t i s a d j u s t e d f o r weight changes. F o r b o t h 1975 e m i s s i o n l e v e l s t h e e s t i m a t e s a r e based on t h e e x t e n t t o which c a r b u r e t i o n and spark t i m i n g c o u l d be changed t o improve economy w h i l e s t i l l meeting t h e NO s t a n d a r d s . The 1977 and 78 p o i n t s a r e based on t e s t s w i t h c a r s equipped w i t h low t h e r m a l i n e r t i a m a n i f o l d s , o x i d i z i n g c a t a l y s t s f o r 1977 and b o t h o x i d i z i n g and r e d u c i n g c a t a l y s t s f o r 1978. The Esso Research and E n g i n e e r i n g Company e s t i m a t e s (A-8) have been used by R u s s e l l T r a i n , A d m i n i s t r a t o r o f t h e EPA, i n a p r e s e n t a t i o n t o t h e House o f R e p r e s e n t a t i v e s (A-9). These e s t i m a t e s appear t o be based on o p t i m i s t i c e x p e c t a t i o n s f o r t h e e f f i c i e n c y o f r e d u c i n g c a t a l y s t s and a t h e o r e t i c a l assessment o f o p t i m i z e d exhaust r e c y c l e systems which i n v o l v e advancing spark t i m i n g , d e c r e a s i n g a i r - f u e l r a t i o , and l i m i t i n g EGR r a t e i n p r o p o r t i o n t o engine air. The M o b i l e s t i m a t e f o r 1973 i n c l u d e s f u e l economy d e b i t s f o r compression r a t i o r e d u c t i o n , r e t a r d e d spark t i m i n g and exhaust gas r e c i r c u l a t i o n (A-10). For the 1975 4 9 - s t a t e s s t a n d a r d , i t i s somewhat lower t h a n t h e average o f t h e p u b l i s h e d e s t i m a t e s shown i n F i g u r e A - l , because we e x p e c t t h a t compression r a t i o w i l l be reduced f u r t h e r o r spark t i m i n g w i l l be r e t a r d e d t o p r o v i d e an a c c e p t a b l e l e v e l o f octane s a t i s f a c t i o n i n 1975 c a r s u s i n g 91 o c t a n e unleaded g a s o l i n e . These changes would reduce f u e l economy. Beyond t h e 1975 i n t e r i m 49-states standard, our estimate o f d e c r e a s i n g f u e l economy p a r a l l e l s most o f t h e p u b l i s h e d e s t i m a t e s shown i n F i g u r e A - l . x

REFERENCES FOR APPENDIX A-1.

L a P o i n t e , C., " F a c t o r Affecting Vehicle Fuel Economy," S o c i e t y o f Automotive E n g i n e e r s N a t i o n a l M e e t i n g , Milwaukee, W i s c o n s i n , S e p t . 1973, Paper No. 730791.


42 A-2.

Statement o f H. L. M i s c h , F o r d Motor Co., t o the U. S. House o f R e p r e s e n t a t i v e s , Subcommittee on P u b l i c H e a l t h and Environment, Dec. 4, 1973, Washington, D. C.

A-3.

Huebner, G. J . and G a s s e r , D. J., "Energy and the Automobile - G e n e r a l F a c t o r s A f f e c t i n g V e h i c l e F u e l Consumption," S o c i e t y o f Automotive E n g i n e e r s , 1973 N a t i o n a l Automobile E n g i n e e r i n g M e e t i n g , D e t r o i t , M i c h i g a n , May 1973, Paper No. 730518. R i c c a r d o , J . J., C h r y s l e r Corp., Testimony b e f o r e the U. S. Senate Committee on P u b l i c Works, Nov. 5, 1973, Washington, D. C.

A-4. Downloaded by UNIV OF SYDNEY on May 4, 2015 | http://pubs.acs.org Publication Date: June 1, 1974 | doi: 10.1021/bk-1974-0001.ch002


A-5.

" F u e l Economy v s . Exhaust E m i s s i o n s , " Attachment 7 o f G e n e r a l Motors Corp. Statement s u b m i t t e d t o the U. S. Senate Committee on P u b l i c Works, Nov. 5, 1973, Washington, D. C.

A-6.

C o l e , Ε. Ν., G e n e r a l Motors Corp., Testimony t o t h e U. S. House o f R e p r e s e n t a t i v e s , Subcom m i t t e e on P u b l i c H e a l t h and Environment, Dec. 4, 1973, Washington, D. C.

A-7.

C a n t w e l l , Ε. Ν., "The Effect o f Automotive Exhaust E m i s s i o n C o n t r o l Systems on F u e l Economy," Ε. I. duPont de Nemours and Co., P e t r o l e u m L a b o r a t o r y , J a n . 14, 1974.

A-8.

P e r s o n a l communication - L. E. F u r l o n g , E s s o Research and E n g i n e e r i n g Co.

A-9.

T r a i n , R. Ε . , Statement and Attachments p r e s e n t e d t o the U. S. House o f R e p r e s e n t a t i v e s , Subcommittee on P u b l i c H e a l t h and Environment, Dec. 3, 1973, Washington, D. C.

A-10.

C l e w e l l , D. Η., M o b i l Oil Corp., Addendum t o Testimony b e f o r e the U. S. Senate Committee on P u b l i c Works, Nov. 5, 1973.


Impact of Automotive Trends and Emissions ... - ACS Publications

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