BMW xDrive

[1] The system uses an electronically actuated clutch-pack differential to vary the torque between the front and rear axles.

Models with the DPC torque vectoring system also have a planetary gearset to overdrive an axle or rear wheel as required.

[2][3][4] These cars use centre and rear differentials with viscous couplings to vary the torque split between wheels.

Unlike its predecessor, the xDrive system uses an electronically actuated clutch-pack differential that engages to send torque to the front axle.

The wet clutch is applied through a high speed electric servo motor turning a cam-shaped actuator disc.

[14] The DPC system is also used by the electronic stability control (DSC) to correct for understeer/oversteer, with one reviewer commenting that it provided smoother results and avoided the temporary power loss associated with the traditional method of using individual wheel brakes in such situations.