Performance and emissions characteristics were evaluated in a Cummins N14-410 diesel engine operating on 12 different blends of methyl tallowate, methyl soyate, ethanol and/or high sulfur No. 2 diesel fuel. Engine performance on each fuel blend, exhaust emissions and smoke were monitored and compared with diesel fuel. Engine performance was found satisfactory without significant drops in power and torque. There was a slight increase in brake specific fuel consumption. Most engine exhaust emissions were not affected by an increase in the amount of alternative fuel in the blend. There was a significant quadratic trend in HC emissions. Brake specific HC emissions were reduced with. increases in alternative fuel in blends up to 80:20 ratio of diesel:alternative fuel; beyond that HC emissions increased.