There's a choice of ten wonderful engines in the A8 range. The petrols begin with the 2.8 FSI, followed by the 3.0-litre, 3.2 FSI, 3.7-litre 4.2-litre and 4.2 FSI. There's even a 6.0 which with 450bhp is as powerful as the V10 in the S8 (reviewed separately) All the petrols are pacey, despite A8's bulk, but the 3.7 feels as though it could do with a bit of extra oomph, however it is as refined as the rest and equally silent when cruising.
The diesels make more sense for higher mileage drivers and there's a good choice with a 3.0 TDI and a 4.2 TDI (which replaced the 4.0 diesel). The 4.0-litre turbo diesel is especially impressive, with smooth power delivery linked to a six-speed automatic gearbox. The 4.2-litre TDI has all the attributes of the 4.0-litre engine, but with greater shove, plus it can return 30mpg delivering a tank range of nearly 600 miles.
The ride is still on the firm side for a luxury saloon, but thanks to the lightweight aluminium construction, and reassurance of Quattro all-wheel drive on most models, the A8 can be driven like a much smaller car. Everything about the A8's behaviour on the road makes the driver feel confident in its ability. It offers good steering feel, turns in neatly, and takes twisty roads in its stride.