Comparisons of Fuel Economy Characteristics of 1969–73 and 1979–80 Automobiles

Fuel economy data developed as a result of two series of automobile tests are compared and discussed. The tests were performed in 1973 and 1979, on representative samples of 1969–73 and 1979–80 model year automobiles respectively. Fuel economy of the test autos was determined under the following conditions: constant speed, the effect of air conditioning, open windows, tire pressure, acceleration rate, and on-the-road tests involving freeway, light city and heavy city driving. Results indicate the effect of the various conditions on fuel economy, and differences between the two generations of automobiles.