Overall rating:

Whether or not you go in for the luxury car thing, it's hard not to be taken in by the Audi A8's charms. The ride, refinement, grunt and build quality are the biggest draws, but this model also represents a big leap forward from the previous version. It truly is at the top of its game and is a worthy rival to the Merc S-Class, which is widely acknowledged to be the car to beat in this class.

Key Facts

Model tested: Audi A8 4.2 TDI quattro SE
Pricing: £65,265 on-the-road
Engine: 4.2-litre turbodiesel V8
Transmission: eight-speed Tiptronic automatic, four-wheel drive
Body style: four-door saloon
Rivals: BMW 7 Series, Jaguar XJ, Mercedes-Benz S-Class
CO₂ emissions: 199g/km
Combined economy: 37.2mpg
Top speed: 155mph (electronically limited)
0-62mph: 5.5 seconds
Power: 345bhp at 4,000rpm
Torque: 490lb.ft at 1,750 - 2,750rpm

Inside & Out:

Pretty much all of Audi's range is in-keeping with its family ethos - squared-off headlamps with LEDs, a large trapezoid grille and a reasonably sober stance. The A8 is no exception and it's very much identifiable as one of the German firm's products. The overall effect is styling that's just subtle enough but allied with a size that gives the car big road presence. Ideal for turning up at a premier.

Love or loathe the sobriety and size of the exterior, you can't help but fall for the cabin. There's no need to ask about build quality - it simply doesn't get much better than this. The thick leather and dark wood of our test car were lovely to behold and the novelty of the massaging seats never wears off. The clever MMI interface is easy to use too, while the stubby, horizontal gear lever is really quite cool.

Ride & Handling:

Comfort is the Audi's trump card and the ride is one of the best of any production car. Only heavyweight rivals like the Mercedes-Benz S-Class can touch it. The suspension and steering are adjustable, but there isn't a huge amount in the changes - the wheel becomes a little heavier or lighter in its action and the ride a little softer or firmer, but that's about it.

Grip is impressive, and it is possible to bowl along at considerable pace in the Audi A8 without fear of losing it. The set-up is more rear-wheel drive biased than ever before, but there's always the reassurance of quattro four-wheel drive when things get slippery. The big Audi is most at home on a long motorway slog, though.

Engine & Transmission:

Our test car was fitted with the 4.2-litre V8 TDI engine and an eight-speed Tiptronic gearbox. You can probably guess just how smooth and refined the driving experience is, but it's worth mentioning anyway. The engine is all but silent from inside - you have to roll down the window and really listen to work out that it's a diesel.

As for the power, 345bhp isn't a headline grabbing figure these days, but it's still more than enough for a saloon and enough to render the sober-looking Audi A8 something of a street sleeper. It's the torque that's the most astonishing thing, though. a peak of 590lb.ft is available between 1,750- and 2,750rpm, so stab the throttle from near idle and the Audi has bucket loads of shove.

Unless you're driving aggressively, you wouldn't know that the gearbox is shifting cogs, such is the smoothness of its action. The lack of noise also helps, but there is an underlying metallic V8 growl if you listen out for it.

Equipment, Economy & Value for Money:

Audi A8 buyers aren't likely to want for much. Clever trinkets like the HDD navigation system and the MMI touch screen interface are standard, while Bluetooth, air suspension and double glazing are also part of the package.

The ability to spec up the car is endless, but with a starting price of £65,245, it's possible to make the A8 very expensive indeed before it leaves the showroom, so choose your options wisely.