- Audi says quattro ultra anticipates all-wheel-drive demand about half a second before it is needed.
- Two clutches disconnect the rear driveline when all-wheel drive offers no advantage, reducing mechanical friction.
- New A6 allroad uses quattro ultra with its diesel and first plug-in hybrid powertrains.
Audi’s A6 allroad can call on its rear wheels before the front tyres lose their grip. The company has outlined how its quattro ultra system watches the driver, road conditions and vehicle movements to decide when all-wheel drive will be useful.
Audi says the system can anticipate that need about 0.5 seconds ahead and complete engagement in around 200 milliseconds. Those are manufacturer claims about the system’s operation, with the aim of having the rear driveline ready for situations such as a slippery surface, a brisk launch or hard acceleration.
Reading the road ahead
The control system continuously assesses steering angle, acceleration, body movements, requested engine load, transmission settings and available friction. It also adapts to the driver’s behaviour and selected driving mode.
That gives it several reasons to engage all-wheel drive proactively. A corner taken enthusiastically, for example, can prompt a different response from steady cruising under light load.
The hardware uses two clutches: an electronically controlled multi-plate unit at the transmission output, and a decoupling clutch in the rear axle differential. When all-wheel drive offers no advantage, both open to disconnect the driveshaft and rear driveline, reducing friction while the car uses front-wheel drive.
Torque distribution changes with conditions. Audi’s internal measurements recorded more than 70% reaching the rear wheels during hard acceleration on dry roads; that figure describes a particular operating situation, rather than a permanent torque split.
Familiar technology, broader choice
Quattro ultra first appeared in the A4 allroad in 2016. It also features in Audi’s A5, A6 and Q5 models built on the Premium Platform Combustion architecture.
In the new A6 allroad, the system accompanies a 220kW 3.0-litre V6 diesel with MHEV plus assistance and an electric compressor. The range also gains its first plug-in hybrid, producing 270kW.
Both versions are now at European dealers. Audi’s release does not disclose New Zealand pricing or a local arrival date for the plug-in hybrid.
