TABLE D.3 Plausible Share of Advance Light-Duty Vehicles in the New-Vehicle Market by 2020 and 2035 (%)

Propulsion System 2020 2035
Turbocharged gasoline SI vehicles 10-15 25-35
Diesel vehicles 6-12 10-20
Gasoline hybrid vehicles 10-15 15-40
PHEV 1-3 7-15
HFCV 0-1 3-6
BEV 0-2 3-10

NOTE: The percentage of hydrogen fuel-cell vehicles considered “plausible” is in contrast to the percentages reported in Transitions to Alternative Transport Technologies: A Focus on Hydrogen (NRC, 2008), which represent “maximum practical” shares.

TABLE D.4 Illustrative Vehicle Sales Mix Scenarios

Market Share by Power Train (percent)
% Emphasis on Reducing Fuel Consumptiona % Light Trucks vs. Cars % Vehicle Weight Reduction Naturally Aspirated SI Turbo SI Diesel Hybrid Plug-in Hybrid Total Advanced Power Train % Fuel Efficiency Increase from Today
Optimisticb
2020 75 40 17 52 26 7 15 0 48 +38
2035 75 30 25 36 26 9 20 9 64 +100
Conservativec
2025 50 40 17 55 24 7 14 0 45 +38
2035 50 40 20 49 21 7 16 7 51 +62

a The amount of the efficiency improvement that is dedicated to reducing fuel consumption (i.e., that is not offset by increases in vehicles power, size, and weight).

b The optimistic scenario meets the new CAFE target of 35 mpg in 2020, and then extrapolates this rate of improvement through 2035. In this case, the average fuel economy in 2035 reaches 52 mpg, roughly double today’s value.

c The conservative scenario achieves the new CAFE target of 35 mpg only in 2025 (5 years later) and extrapolates this rate of improvement through 2035, when the average fuel economy reaches only 60 percent above today’s value.

D.1.4 Cumulative Effects

Figure D.1 shows, for the conservative and optimistic scenarios, the corresponding annual gasoline consumption of the United States in-use light-duty vehicle (LDV) fleet from the present out to 2035. A no-change baseline assumes that all of the efficiency improvements go to vehicles size, weight, and power, as has occurred since 1982. The cumulative fuel savings under each scenario compared with this no-change baseline are indicated. Note that this no-change baseline includes some growth in overall fleet size and miles driven but no resulting change in vehicle fuel economy. No similar assessment is given for GHG emissions.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement