BMW xDrive

BMW xDrive is BMW's four-wheel drive system that powers the X3, X5 and 2006 and later xd and xi 3 Series and 5 Series models.

Instead of a 60-40 (rear-front) power split (which all millennium four-wheel drive BMW's exhibit — 325xi, 330xi, early X5) with power being cut to wheels which lost traction through DSC (Dynamic Stability Control), xDrive allows power to be split between the front and rear axles through use of a multiplate clutch located between the gearbox and the Cardian shaft. This setup allows xDrive vehicles to split power in virtually any way it pleases. If the car felt like it was in a threatening situation (note not an unstable one), xDrive would react immediately, often before the driver ever knew of its intervention, to alleviate traction and control of the vehicle.

xDrive is also closely knit with DSC. In the case that wheelspin still occurs while xDrive is or has been shifting power, DSC can brake independent wheels to regain traction. xDrive also helps in cornering. When the vehicle senses that it was about to understeer or oversteer the vehicle can independently cut traction to either of the front wheels or rear wheels to help regain stability and keep the driver on the road.

xDrive was one of the first technologies used to intervene before the driver was aware that the car was becoming or would become unstable. Its intervention is transparent to the driver.