The paper describes the analysis of a valve control of a drive with a rotary hydraulic motor. The valve control is realized by a throttle valve. The individual drive characteristics are measured on the experimental device, i.e. the control and the torque-speed characteristics. The experimentally determined characteristics are compared to the theoretically calculated characteristics. Subsequently, the efficiencies of the tested rotary hydraulic motor are experimentally determined, i.e. the volumetric, mechanical-hydraulic and total efficiencies. The theoretical computational equations are subsequently supplemented by the experimentally determined efficiencies of the hydraulic motor. Theoretically determined characteristics of the drive, including efficiencies of the hydraulic motor, are again compared to the experimentally determined characteristics. The mathematical model of the experimental device is also assembled. This mathematical model is verified in a steady state.