Propulsion system for all-wheel drive motor vehicles

The invention relates to a propulsion system for all-wheel drive motor vehicles, having a device for propulsion distribution to the front and the rear differential which transmit the drive output to the wheels assigned at the time, and with a device for coupled, variable distribution of the propulsion forces in the transverse and longitudinal directions of the vehicle depending on the operating situation of the vehicle for influencing the driving behavior, especially for improving the driving agility and driving stability. In the process the rear differential is combined with an overriding drive, by means of which the drive torques can be shifted to the rear wheels in alternation in the transverse direction of the vehicle, the rpm ratio or rpm error being dictated by means of the overriding drive at the design point so that at a given curve radius which is assigned to the design point and which does not correspond to the narrowest curve, a reversal of the direction of the rotational speed difference takes place and thus the torque is not shifted to the wheel on the outside of the curve. By means of the propulsion distribution device the drive torques can be shifted in alternation between the front differential and rear differential in the longitudinal direction of the vehicle.