Alcohol-fueled vehicles usually produce more air toxics than any other vehicle fuel. Methanol and ethanol vehicle exhaust emissions are high even when compared with conventional unleaded gasoline vehicles. Total VOCs and VOCs adjusted for reactivity are usually the same as or higher than any other fuel. Exhaust emissions need improvement to take advantage of alcohol vehicles low evaporative emissions. Evaporative emissions are lower in alcohol-fueled vehicles than gasoline vehicles.
Alcohol fuels lose one-half gram per mile per vehicle less than conventional gasoline vehicles.
Air quality could improve greatly if many alcohol-fueled vehicles were on the road and their tailpipe emissions improved. The electricity produced at the regional power plant causes emissions. The mass of these emissions is dependent on the local power plant. In Santa Barbara, California, a diesel transit bus was compared to an electric bus of the same model. The diesel emitted total emissions, which include carbon monoxide, particulate matter, NOx, and VOCs, of 34.6 grams per mile, while the electric bus's emissions were only 0.3 grams per mile total emissions at the power plant.