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Automotive Fuel Economy: How Far Can We Go? (1992)
Commission on Engineering and Technical Systems (CETS)

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198
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The following HTML text is provided to enhance online readability. Many aspects of typography translate only awkwardly to HTML. Please use the page image as the authoritative form to ensure accuracy.


Automotive Fuel Economy: How Far Should We Go?

TABLE B–1 Estimates of Fuel Economy Improvement Potential of Various Technologies (percent)

TECHNOLOGY

BASELINE

EEA

SRI

BSA

FORD

GM

CHRYSLER

TOYOTA

HONDA

NISSAN

MITSUBISHI

ENGINE TECHNOLOGIES

GENERAL

Roller cam followers

Flat followers

2.0

1.7

0.3

3.0

1.5

2.4

0.8

1.0

1.4

1.3

Friction reduction, -10%

Base 1987

2.0

2.0  

 

2.0

1.0

0.5

0.8

1.0

1.4  

 

Accessory improvement

Conventional

0.5

0.7  

 

0.7

0.0

1.4

0.5  

 

0.2

0.8

Deceleration fuel restriction

None

1.0

1.0

 

1.0            

 

 

 

 

 

 

Compression ratio, +.5

9:1 (EEA 4-V only)

[a]

2.0

 

1.5

1.0  

 

1.3

 

 

1.0

FUEL SYSTEMS

Throttle-body fuel injection

Carburetor

3.0

2.6

3.0

3.0

2.5

3.4

0.8

1.0

3.3  

 

Multipoint fuel injection

Carburetor

5.0 [b]

4.6

3.1

6.0

4.0

4.9

2.5

3.5

4.3  

 

VALVE TRAIN

Overhead camshaft

Overhead valve

3.0

2.5

1.2

3.5

1.5

2.0  

 

0.8

2.0  

 

4 valves per cylinder

2 valves

5.0

3.0

2.1

3.5

3.0

3.5

4.5

2.0

3.4

 

Variable valve timing

Fixed timing

6.0

2.6  

 

3.0

2.0

1.5

2.0

2.5 [c]

2.7

 

REDUCED NUMBER OF CYLINDERS

4-cylinder

6-cylinder

3.0

0.0

1.2

-3.0

0.0

0.0

0.0

0.0

0.0  

 

6-cylinder

8-cylinder

3.0

1.0

-0.9

0.0

0.0

0.0

0.0

0.0

0.0

 

TRANSMISSION TECHNOLOGIES

Torque converter lock-up

Open converter

3.0

2.0

2.8

2.0

3.0

3.0

2.5

3.0

3.2

 

Electric transmission control

Hydraulic

0.5

0.5

0.5

0.5

0.0

0.5

0.5

0.5

0.6  

 

4-speed Automatic

3-speed auto

4.5

2.8

2.9

3.0

4.0

2.0

2.3

1.8

3.0  

 

5-speed Automatic

3-speed auto

7.0

3.3

 

5.0

4.5

3.0

3.5

3.3

4.0  

 

Continuously variable transmission

3-speed auto

8.0

4.8  

 

5.5

4.5

3.0  

 

3.8

5.5  

 

5-speed Manual [d]

3-speed auto

8.0

4.8

0.0

5.5

0.0

0.0

0.0

0.0

0.0  

 

ROLLING RESISTANCE, AERODYNAMICS, AND WEIGHT

Front wheel drive

Rear wheel drive

10.0

0.5

0.8

1.0

0.0    

 

 

1.1

3.0  

 

Aerodynamics

Base

2.3

2.4

2.7

2.0

3.1

2.0

2.0

1.5

1.2

1.7

Weight reduction, -10%

Base

6.6

5.0

9.1

5.5

8.0

5.0

5.5

5.0

6.0

 

Electric power steering

Conventional

1.0

1.4  

 

1.5

0.5

1.0

1.0

1.0

1.0  

 

Advanced tires, -10%

Base

1.0

1.0

0.6

1.0

0.5

0.5    

 

 

1.0

1.0

Advanced lubricants

Conventional

0.5

0.3  

 

0.2    

 

 

0.5

0.5

 

 

[a] Fuel economy benefit for EEA incorporated into 4-valve engine.

[b] Apportioned to account for incorporation of limited deceleration fuel restriction in multipoint fuel injection.

[c] A savings as large as 12.5 percent can be inferred from discussion in Chapter 2 or Appendix C.

[d] Fuel economy benefit assumed same as that of CVT over 3-speed automatic transmission.

Source: Committee adaptation of summary of presentations to the committee, July 1991, prepared by A. Gilmour (Ford, 1991). Baseline technologies are arbitrary and have been changed from some original sources to put all estimates on a comparable basis.

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