The paper presents fundamentals characterising the operation of turbochargers and the dependencies essential for the calculation (the use of balance equations of a turbocharger this purpose) of the total efficiency of a compressor set with respect to the power balance of the respective devices of a turbine. For the assumed conditions of the engine operation – an optimum power distribution has been carried out on the basis of a theoretical analysis as far as the total efficiency is concerned in the compressor set and in the turbine set of a supercharging device. The required pressure drops in the turbine, essential to ensure the power in the compressor have been carried out with respect to the efficiency of each device.