The suspension developed specifically for the BMW X5 M and X6 M with its double-wishbone front control arms and integral four-link rear axle offers M-specific geometry and damping. This is accomplished through optimized control arm and A-arm bushings at the front, as well as stiffer axle support mounts at the rear.
As part of the advanced Integrated Chassis Management system, which networks all drivetrain and suspension components, both models feature standard self-leveling rear air suspension and Adaptive Drive with Electronic Damping Control (EDC) and Active Roll Stabilization (ARS). The special version of Adaptive Drive tailored to the requirements of BMW M lowers the entire vehicle by 10mm or 0.4" versus the standard BMW X5 and BMW X6.
To quickly and reliably process data, Adaptive Drive uses the high-speed FlexRay data transmission protocol. FlexRay enables Adaptive Drive to transfer data through the vehicle's on-board network at an extremely fast rate. This enables lightning-quick changes to settings for individual shock absorbers, sway bars, and other components as conditions and driving demands warrant. For example, if the front wheel encounters a bump, the system responds quickly enough before the rear wheel reaches the same bump. On the X5, X6, and 7-Series, BMW is the first carmaker in the world to use FlexRay as a regular technology.
The special Servotronic steering developed for the BMW X5 M and X6 M provides variable steering assistance geared to the road speed of the vehicle. This allows the driver to negotiate parking maneuvers with lower effort while preserving exact feedback and the highest standard of steering precision at higher speeds.
The degree of power steering assistance is defined by two control maps. Apart from the standard configuration, the driver is able to select the Sport Mode through the Adaptive Drive button or the M Drive button on the steering wheel. This activates a sports driving control map with higher control forces for particularly dynamic driving conditions.
When changing from Normal to Sport Mode, the system alters not only the Servotronic steering control map, but also the damper setting, with the shock absorbers of the vehicle being significantly stiffened in Sport Mode. In conjunction with Active Roll Stabilization, this allows an exceptionally high standard of linear lateral forces in dynamic bends and on fast, winding roads, and keeps body roll to a minimum.
Outstanding stopping power with fade reduced to a minimum is guaranteed by the high-performance M brake system, which combines giant four-piston fixed calipers at the front with floating calipers at the rear, combined in each case with large, internally-vented lightweight discs. The brake rotors themselves measure 15.6" in diameter at front and 15.2" at rear. They feature a riveted connection to the aluminum hats with the cast-iron discs.
The BMW X5 M and the X6 M are the only vehicles of their type equipped with staggered-size tires front and rear, running on 20" light-alloy wheels. The choice of run-flat tires in sizes 275/40-20 at the front and 315/35-20 at the rear is a result of the special setup of both models, with the emphasis on rear-wheel power and dynamic handling balance. This promotes exceptionally good transmission of power to the rear axle and precise, razor-sharp steering behavior of both models. Transitional stability is also world-class.