BMW xDrive and DSC management

As soon as driving conditions deviate from normal, BMW's xDrive system acts immediately, since the all-wheel-drive system is networked directly and closely with DSC Dynamic Stability Control.

The electronically controlled multiple-plate clutch shares out drive forces variably between the front and rear axle, feeding the right drive power to the respective axle whenever the driver takes a bend dynamically and at high speed, significantly minimising any under- or oversteer in the process, all instantaneously, requiring 100 milliseconds at the very most.

The driver, in turn, gets a smoother and more harmonious behaviour in bends, an appropriate reduction of steering forces and an even higher standard of motoring comfort, with DSC Dynamic Stability Control intervening in the brakes at a later point in time.

In an extreme case, BMW xDrive is even able to fully disconnect the front and rear axle from one another or, conversely, connect them rigidly to one another as one combined drive system. So proceeding from the standard 40 : 60 power distribution front-to-rear, the spread of engine power may be varied infinitely all the way from 100 : 0 or 0 : 100.

Without the driver even noticing, therefore, his BMW becomes a rear-wheel-drive-only or – should this be required on account of a very low frictional coefficient at the rear, a front-wheel-drive-only car at least for a few short moments. Should a rigid connection of the two axles be required, on the other hand, xDrive builds up a longitudinal lock, providing permanent all-wheel drive with 50 : 50 power distribution.

A BMW equipped with xDrive retains all the functions of DSC, including the option to deactivate the system, while ABS always remains active. xDrive itself cannot be switched off, a further advantage of interaction between xDrive and DSC being the lateral lock function feeding power to the same degree to both wheels on one axle. Next