This paper presents the results of experimental research on the energy and economic performance of the 4DC engine (110X125) powered by B100 biodiesel and mixtures of diesel and B20 and B50 biodiesel. A particularly important role is played by the speed characteristic obtained at maximum load, on which the highest values of the effective power Ne and the engine torque Me are mentioned, as well as the hourly fuel consumption Ga, specific to fuel ge. The measurements were performed according to standard methods. The analysis of the results obtained shows that biodiesel influences the energy and economic performance of the compression ignition engine, ie the rated engine power Ne have decreased by about 8,65% compared to diesel, due to the fact that the calorific value of biodiesel (37,7 MJ/kg) is lower compared to thecalorific power of diesel (42,5 MJ/kg). At the same time, there has been an increase in the hourly Ga consumption of biofuel blends and pure biodiesel compared to diesel consumption in all speed characteristic research regimes. It has also been established that refueling the compression ignition engine with biodiesel and biodiesel and diesel blends practically does not affect its performance and does not require further adjustment of the fuel supply system.