This study is devoted to determining performance characteristics of biodiesel as a diesel engine fuel. An engine performance test using sunflower methyl esters exhibited characteristics very similar to regular diesel. The test values obtained from a 2.5 lt. 4 cylinder Peugeot XD3p157 engine shows that torque values obtained by the two types of fuels are 5%-10% in favor of regular diesel. Obviously, power values will be the engine revolutions times this percentage with regular diesel. Specific fuel consumption, however, is better with biodiesel. This means that a better combustion characteristic is achieved with biodiesel, which compensates for its lower calorific value. Soot emissions are slightly less with biodiesel, as expected, due to the improvement in specific fuel consumption.