An experimental program was conducted as a cooperative effort between the Southwestern Bell Telephone Company and the Department of Energy’s Bartlesville (Okla.) Energy Technology Center to determine the effects of a gasohol fuel when compared to a control gasoline. The test vehicles used in this program were separated into two groups--a test fleet and a control fleet. The vehicles consisted of several vans, trucks, and automobiles routinely used in commercial service. The laboratory analysis included testing the vehicles on a controlled environmental chassis dynamometer at a constant ambient temperature of 75° F.Field measurements and data collection included road driveability, in-use fuel economy, and fuel system failures. Laboratory analysis provided information on exhaust emissions, fuel economy, and trace metals in the crankcase lubricating oils. The effect of varying the chassis dynamometer inertia weight was also examined.A reduction in regulated exhaust emissions was found with gasohol, but there was considerable variation among the vehicles. No difference was detected in vehicle fuel economy at actual load weights. Unregulated emissions were higher for gasohol, but the absolute levels were low. The fuel economy with gasohol relative to gasoline was improved as the vehicle weight was increased. A larger quantity of copper was found in the crankcase lubricating oil of the vehicles operating on gasohol when compared to the vehicles operating on gasoline. Driveability was poorer with gasohol, especially during the winter and summer seasons.