How Audi is eliminating body roll

The adaptive air suspension in the Audi SQ7 features an electromechanical active roll stabilization system. That's a fancy way of saying they've put an electric motor inside their sway bar. Each sway bar (front and rear) has access to a 48V power supply, and is capable of delivering 1200 Nm of torque from a 1.5kW motor. That's in part thanks to a three-step planetary gear reduction of 200:1.

The fascinating thing about this system is it allows for the vehicle to change it's understeer/oversteer tendencies in real time. By stiffening the front sway bar relative to the rear, this increases the amount of load transfer the outside front tire sees, increasing understeer. By stiffening the rear sway bar relative to the front, this increases oversteer. This can be balanced for ideal handling. The video describes how this all works!