Audi’s famous all-wheel-drive system is synonymous with the brand and has proved its popularity by enduring 35 years of technological change and upgrades by the automaker.
The eight millionth quattro-equipped Audi, an all-new Q5 SUV, in Garnet Red, left the production line at a brand new plant in San José Chiapa, Mexico, last week.
The technology was originally introduced in 1980 on the legendary Ur-quattro and is now available on over 100 model versions. Standard in the Audi Q7, the Audi A4 allroad quattro, the Audi A6 allroad quattro, the Audi A8, the Audi R8 and all S and RS models, the quattro all-wheel drive system is it is available as an option in all other model series.
The setup depends on the type of model. For example, in the compact model series with transverse-mounted engines, there’s an electronically controlled hydraulic multi-plate clutch installed on the rear axle, while in the mid-engined R8 it sits on the front axle. Depending on the driving situation, these active systems distribute drive torque variably to both axles.
The self-locking centre diff used in many Audi models with a longitudinally installed, front-mounted engine, is a purely mechanical planetary gear. Usually the drive torque sent to the front and rear wheels is split to a 40:60 distribution.
Some of the top-of-the-range engines are fitted with the sport differential, available on the rear axle. This actively distributes the torque between the rear wheels. 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.
The latest version of Quattro is tailored to cars fitted with longitudinally mounted engines and has software to disengage the all-wheel-drive by means of a decoupler in the rear axle differential, when it determines that all-whell-drive is unnecessary, powering the car with the front wheels to cut fuel consumption.