Mid-range Audi does not use Torsen differentials anymore. Currently, only Volkswagen Touareg, RS7, S8 and other models use Torsen differentials. Audi has fully used Torsen differentials on mid-range A4L, A6L and other models. A crown gear differential is used, and on low-end transverse platform models such as the Q3, Audi uses BorgWarner's Hande fifth-generation four-wheel drive system.
The reason why the Torsen differential can be used as a central differential in cars is mainly because it has the characteristics of a purely mechanical structure with small power loss, direct power transmission, and can withstand large torques. It also One of the most critical features is that the turbine worm used in the Torsen differential has self-locking ability. When the wheels slip, it will immediately self-lock to avoid power loss. Based on these characteristics, Torsen differentials are widely used in some full-time four-wheel drive models. In addition to Audi, they are also widely used in hardcore off-road vehicles such as Toyota Prado, Cruiser, Mercedes-Benz G, and Lexus LX570. Of course, the purpose of using Torsen on these models is not for off-road use, but mainly for road driving capabilities. Large hardcore off-road vehicles need to maintain stable four-wheel drive capabilities when driving at high speeds to increase driving stability.
In extreme off-road conditions, the center differential must be locked. The Torsen differential type C, which is currently widely assembled for center differentials, can only distribute a maximum of 60% of the power to the front axle or 80% of the power to the rear axle, which means it cannot be completely locked. Power will still be lost. In fact, we can also see that since the Prado 2700 does not have a central differential lock, it only relies on the Torsen differential to distribute power to the front and rear axles. For inter-wheel limited slip, it can only rely on EDL, and its ability to escape difficulties is really average! Advantages and Disadvantages of the Torsen Differential
As mentioned before, the advantages of the Torsen Differential are its pure mechanical structure, direct power transmission, and ability to withstand large torques. However, due to the It has a purely mechanical structure, is relatively heavy, has a high purchase price, and has relatively high fuel consumption. In view of the increasingly stringent emission requirements, weight reduction and fuel consumption have become an increasingly serious problem for Audi. In addition, the Torsen differential patent has been purchased by JTEKT, a subsidiary of Toyota. Based on Volkswagen's tonality, in order to avoid being controlled by others, it will definitely find an alternative. This spare tire solution is the crown gear differential.