In response to the occurrence of the increasingly severe ambient ozone exceedances, regional environmental managers are examining the possibility of a cleaner fuel for automobiles. At this time the leading candidate is methanol. In anticipation of a shift to methanol, variable-fueled automobiles capable of operating on gasoline and/or methanol are being developed. The study examines both the exhaust and evaporative emissions from a prototype General Motors Variable Fuel Corsica. Results are reported for tests conducted at temperatures of 40, 75, and 90 f, and for fuels M0, M25, M50, M85, and M100. In addition to regulated emissions and fuel economy, emission rates for methanol, aldehydes, and a large number of hydrocarbon compounds were determined. The data indicate that increasing the fuel's methanol content does not affect the exhaust organic emission rate (calculated in accordance with the regulation) from variable-fueled cars, but formaldehyde and methanol comprise increasingly greater portions of the organic material while hydrocarbons comprise less. The effect of ambient temperature on both exhaust and evaporative emissions is similar to its effect on gasoline cars: organic and carbon monoxide exhaust emissions increase substantially at the lower temperatures, and evaporative emissions increase steadily with increases in temperature. (Copyright (c) 1990 Air & Waste Management Association.)