Audi

Slotting in above the single-turbo 204PS and 245PS versions of the 3.0 TDI that already feature in the A6 and A7 Sportback ranges, the latest V6 has a two-stage turbocharger group that delivers a maximum boost pressure of up to 3.2 bar, helping the A6 3.0 BiTDI quattro Saloon to lunge at the horizon and pass the 62 mph marker in 5.1 seconds, and the A6 Avant and A7 Sportback to do the same in 5.3 seconds. An electronically limited top speed of 155 mph is common to all versions.

Like the existing TDI engines, the new star performer is backed up by technologies from the Audi modular efficiency platform, including start-stop and recuperation systems and the innovative thermal management system that quickly brings the coolant and oil up to their operating temperatures. With their help, combined economy in A6 and A7 Sportback models is on an equal footing at 44.1 mpg.

Thanks to an actuator in the auxiliary channel of the exhaust system, the BiTDI A6 and A7 Sportback models don't sound like they should be capable of such level-headed economy figures. The actuator system essentially consists of a speaker which imposes a defined oscillation pattern on the exhaust flow and transforms the typical TDI exhaust note into a more sonorous roar that is closer to the output of a high-performance petrol engine.

Without exception, power is transmitted from the BiTDI engine via an eight-speed tiptronic transmission to the latest generation quattro all-wheel-drive system, which features a self-locking centre differential and torque vectoring for optimum traction and stability. A sport differential which distributes power in continuously variable proportions between the rear wheels is available from the options list to sharpen and quicken response further.

The mighty new BiTDI engine is available in conjunction with SE and S line specification in the A6 Saloon, A6 Avant and A7 Sportback. The forthcoming A6 Allroad Quattro, due to open for order in February, will also offer this unit.