There are presented the results of experimental investigations on utilization of pure rape seed oil to feeding the self-ignition engine mounted on the agricultural tractor. A two-tank fuel system with heating of rape seed oil was mounted in the engine. The engine starting was performed on diesel oil, then upon achievement of appropriate temperature the system was automatically shifted to a plant fuel. There was investigated the effect of engine design parameters on the power, torque and specific fuel consumption. The investigations showed that feeding of the engine with pure rape seed oil resulted in the decreased power by 12%, decreased torque by 9% and increased specific fuel consumption by 15%. The change in the fuel injection advance angle affected the specific fuel consumption; its best value was obtained at the angle of 15°.