Factors Affecting Vehicle Fuel Economy

The recent history of automotive fuel economy in the United States is reviewed. As of the 1973 model year, the individual typical car on Ford's city-suburban route has experienced a 22% decline in fuel economy compared with that of 1967. In the aggregate, however, the decline has not been as great because an increasing proportion of small cars has entered the vehicle population.

The factors which have contributed to the fuel economy decline of the typical car are average weight and engine displacement increases and measures taken to reduce exhaust emissions. As of the 1973 model year, emission controls have accounted for 60% of the total 22% decline based on Ford's city-suburban route.