The newly developed, permanently available quattro system with ultra technology will soon become available to order in the UK, initially in conjunction with the 2.0-litre TFSI petrol engine. Three TDI diesels will open for order at the end of April: the 2.0 TDI with 187 bhp and the 3.0 TDI with 215 or 268 bhp.
Designed for Audi models with longitudinally installed engines, the new technology delivers benefits in terms of both fuel efficiency and CO2 output. The system deactivates all-wheel drive when it is not needed, but ensures that it is also permanently and instantaneously available, significantly reducing the potential fuel consumption penalty for all-wheel drive.
A networked sensor system communicates with a multi-plate clutch and integrated decoupler on the rear axle, allowing the A4 allroad to switch between front- or all-wheel drive in a split-second depending on the driving conditions.
The system works predictively, looking ahead by means of an array of sensors and the continuous analysis of the driving dynamics, road condition and driver behaviour.
With predictive activation, the quattro control unit reflects the driver’s style, the status of the ESC and the mode selected in drive select, and on the trailer detection system.
With reactive activation, which should rarely occur in practice, the system reacts to sudden changes in the coefficient of friction. These occur, for example, when the wheels go from dry asphalt to a sheet of ice.
Other drivetrain features include the Audi drive select adaptive driving system which allows the driver to adjust the all-wheel-drive properties to suit his or her individual requirements and a zero-lag self-locking centre differential. During normal driving operation, the differential distributes the power asymmetrically, with 60 percent flowing to the rear axle and 40 percent to the front axle. This increases to a maximum of 70 per cent up front and 85 per cent to the rear when required.
The Audi A4 allroad quattro also has an increased ground clearance of 34 mm over the standard A4 Avant and optional adaptive suspension with damper control, as well as robust underbody guards and contrasting wheel arches.