Already used in the Q7 and A6 Allroad, the new 4.2-litre FSI engine offers 350bhp – a 15bhp increase over the old engine.
In the A6 saloon and Avant, the FSI engine cuts the 0-62mph time by 0.2 seconds to 5.9 and slashes CO2 emissions by 34g/km to 257. Fuel economy is boosted to an average of 26.1mpg compared to 23.9 for the old version.
In the A8, the 0-62mph time drops from 7.6 to 6.1 seconds, economy is up very slightly to 23.9mpg and CO2 emissions fall 5g/km to 283.
Prices start at £44,475 (up from £44,120) for the A6 and £58,305 (£57,890) for the A8.