The intelligent all-wheel-drive control system operates predictively and continuously evaluates parameters relating to driving dynamics, road conditions, and driver behavior. Among other things, it monitors and anticipates steering angle, load demand, transmission setting, lateral and longitudinal acceleration, body movements, and the friction coefficient. The system learns as it goes and adapts its operation to the driver profile and the selected Audi drive select mode: the more efficiently the vehicle is driven, the less active the all-wheel-drive system is. The more dynamically the vehicle is driven, the more frequently quattro all-wheel drive engages. Driver behavior and the duration of all-wheel-drive activity in specific situations are continuously incorporated into the calculations. This means the computational model predicts about 0.5 seconds in advance when all-wheel drive will be beneficial. If required, the complete engagement process – synchronizing the previously disconnected components and closing the decoupling clutch in the rear axle differential – takes approximately 200 milliseconds. As a result, all-wheel-drive is ready before it is needed. When setting off, cornering dynamically, accelerating sharply, or driving on road surfaces with a reduced friction coefficient, the system predictively prevents wheel slip.
