Audi Quattro System
There are six generations of the Audi Quattro system.
First Generation
In the first generation Audi AWD system, the front, rear and center differentials were open as standard. The rear and center differentials could be locked by simply pressing a button inside the cabin, usually near the handbrake.
Second Generation
In the second generation, the center differential was changed to a Torsen Type 1 differential. Torsen is a portmanteau of “torque sensor.” Type 1 torque distribution was 50/50 between the front and rear axles, but if one wheel spun, the differential would automatically shift torque (up to 75%) to the axle that needed it more.
Most vehicles at the time still had a manually lockable rear axle differential. Some larger vehicles had a Torsen differential on the rear axle for better handling.
Third Generation
The third generation quattro system was only used on Audi V8s from 1988 to 1994. On vehicles with manual transmissions, the center and rear axle differentials were still Torsen Type 1, and the front axle differential was open. In autonomous cars, a new technology was introduced in the center differential: a planetary gear with an electronically controlled locking clutch. The Type 1 Torsen rear differential and the open front differential still remained.
Fourth Generation
The fourth generation Electronic Differential Lock (EDL) uses ABS sensors to detect wheel rotation and applies the brakes so that the opposite wheel can receive more torque from the open differential. This was adopted for the front and rear differentials, leaving the center differential with the Torsen Type 1 rear differential technology.
Fifth Generation
In 2006, the fifth generation Quattro introduced another type of Torsen. Type C is also known as the “self-locking” center differential. It has a standard 40/60 split that can automatically send up to 80% of the torque to the axle that needs it. The front and rear differentials remain open with EDL.
A sport differential was available as an option for the rear differential. This system used torque vectoring to improve safety and handling by using various sensors to better move the car in the direction the steering wheel is steered.
Sixth Generation
The final generation of Audi AWD systems, introduced in 2010, replaced the Torsen center differential with a “crown gear” differential. Depending on the need, up to 70% of the torque can be transmitted to the front wheels and up to 85% to the rear wheels.
This differential is better suited to any driving condition or operation. This technology ensures a more reliable and faster response while being lighter and more compact.