Light Duty Automotive Fuel Economy …. Trends Through 1978

This is an analysis of fuel economy data compiled by the U.S. EPA on passenger cars from model years 1958-1978, and light-duty trucks from 1975-1978. The paper includes new fuel economy data on pre-1975 cars, which indicates that fleet average MPG for the older models is slightly higher than had been previously estimated.

Analysis of 1977-78 passenger cars and light trucks' economy characteristics in terms of the new EPA/DOE “Vehicle Size” classes provides new insight into fleet MPG characteristics as related to model changes.

The methodology for isolating fleet and individual manufacturer fuel economy changes due to specific factors such as system optimization and weight mix shifts has been refined, and is applied for the first time to trucks and to comparison of 49-states and California vehicles.

The vehicle fleet which is the basis of the analysis includes the top-selling 18 car makers and 8 truck manufacturers.