A Detroit 6V-92 TA coach diesel engine and a Cummins NTA-855-C diesel engine were operated on fuels produced by blending methyl soyate with No. 2 diesel fuel. Seven fuels, namely, neat diesel fuel; 90:10, 80:20, 70:30, 50:50 and 25:75% (v/v) blends of diesel fuel:methyl soyate; and neat methyl soyate were prepared and tested for the performance of the Detroit engine using standard rest code SAE J1349. Specific gravity, viscosity, and heating values of all seven fuels were determined. Power developed by the engine, brake specific fuel consumption, and emissions analyses including brake specific hydrocarbon, brake specific oxides of nitrogen, brake specific carbon monoxide and smoke were measured. The performance of the engine was found to be satisfactory without a significant reduction in power output on methyl soyate blends up to 30%. Based on these results, the Cummins engine was nln on four fuel blends, namely neat diesel fuel; and 90:10, 80:20 and 70:30% (v/v) blends of diesel:methyl soyate. The performance of the Cummins engine was found to be satisfactory without any significant reduction in power: Engine exhaust emissions, except NOx were reduced for both engines as the concentration of the methyl soyate in the fuel increased.