The system is mainly used only on models with a maximum torque of up to 500 Nm.
Audi opens a new chapter in the history of Quattro. The Quattro drive can now disengage the rear wheels, just like the Ultra.
Audi Quattro has meant four-wheel drive until now. This has already changed. Quattro Ultra is a drive system that can decouple the rear wheels from the drive. Quattro Ultra is used for the first time in the new Audi A4 Allroad.
Quattro Ultra mainly front-wheel drive
The constant search for efficiency gains led to this result. With conventional Quattro drive, the rear wheels are in constant contact with the drive, even when no traction is required. A constantly rotating differential and propeller shaft require power and fuel, respectively.
In the new Quattro Ultra, all-wheel drive is automatically disabled when not needed, but remains available at all times. The car has consistently good traction, and accordingly more often only with front-wheel drive. Audi has calculated that the efficiency of the system averages 0,3 liters per 100 kilometers.
Rear-wheel drive is only activated when the electronic control system detects a loss of traction on the front axle. This takes into account factors such as slip, swing speed, trailer towing, driving style, etc. Rear-wheel drive can be engaged in a split second.
More powerful models stay with the old Quattro.
Rear-wheel drive exhaust conversion is carried out by two removable couplings. Multi-plate clutch just behind the gear and rigid clutch in the rear axle gear. The Quattro Ultra system is mainly used only on models with a maximum torque of up to 500 Nm. All higher torque versions will continue to be equipped with the Quattro permanent drive.