Audi is celebrating a special milestone this year with the production of its 8 millionth Audi with quattro-drive rolling off at the company’s new production line in San José Chiapa. The milestone car is a garnet red Audi Q5 2.0 TFSI quattro.
Quattro technology made its debut in 1980, and today it is available in more than 100 model versions. The quattro all-wheel drive system is standard in the Audi Q7, the Audi A4 allroad quattro, the Audi A6 allroad quattro, the Audi A8, the Audi R8 and all S models and RS models, and it is available as an option in all other model series.
In 2015, 44% of all Audi customers worldwide chose models equipped with quattro drive. The Audi Q5 topped the list with about 262,000 units. The quattro models generated particularly strong sales in the United States, Canada, Russia and in the markets of the Middle East. In Germany quattro sales totaled 122,048 cars.
Audi offers the quattro drive in different versions tailored to each model. For the compact model series with transverse-mounted engines, an electronically controlled hydraulic multi-plate clutch is mounted at the rear axle. On the R8 mid-engine sports car, the multi-plate clutch is at the front axle. According to the driving situation encountered, these active systems distribute drive torque variably to both axles.
The self-locking center differential used in many Audi models, with a longitudinally mounted front engine, is a purely mechanical planetary gear. Normally it splits the drive torque sent to the front and rear wheels with a 40:60 distribution.
Sport differential is available on the rear axle with some of the top-of-the-range engines. It actively distributes the torque between the rear wheels by means of two superposition units, each with an electrohydraulic multi-plate clutch. In extreme cases, almost all of the torque is sent to one wheel – the system actually pushes the car into the curve, eliminating any chance of understeer.
Audi’s latest development step is a quattro with ultra technology. It is likewise designed for models with a longitudinally positioned engine. Here, an actively controlled multi-plate clutch at the end of the transmission distributes the torque variably between the drive axles in all-wheel drive operation. A decoupler in the rear axle differential can additionally open the connection to the rear wheels. Both clutches are opened in driving situations where the all-wheel drive doesn’t offer any advantage. This way, the parts of the rear drivetrain responsible for drag are not engaged. The system’s control unit uses a multitude of data to produce a model of the vehicle’s status projecting about half a second into the future. If the system detects, for instance, that the inside wheel is about to lose grip, it switches predictively to all-wheel drive. As a result, the all-wheel drive is always ready when it is needed. The new concept considerably boosts efficiency without diminishing traction or driving dynamics.