A drive train for a compressor and a hydraulic pump of a motor vehicle, and a method of use are described. The system includes a hydraulic power steering system, an electric superimposed steering system for providing steering assistance, and a motor vehicle drive motor with a common output shaft for driving the compressor and the hydraulic pump. Also provided are means for reducing the power which is supplied to the compressor and to the hydraulic pump via the output shaft, when demands made of the compressor and of the steering assistance system permit reduced power operation. The power which is supplied to the compressor and to the hydraulic pump via the output shaft may be reduced substantially to zero when operation of the compressor is unnecessary and the electric superimposed steering system is sufficient to provide alone the steering assistance.