In conclusion, the A8 hits its intended targets square on - it's a great director's car that plays the role of limousine perfectly. Yet it also looks exclusive, as ample external jewelery, and has a sharpness that the old car now appears to lack

Audi is bullish about the prospects for its third generation A8, but with good reason - it's lighter, more efficient and faster than the outgoing car. Although this early declaration might seem like something of a plot spoiler for anyone reading this, it certainly shouldn't be unexpected.

The new car, which will be available with 3- and 4.2-litre TDI engines as well as a 4.2-litre FSI petrol power unit, and UK deliveries are expected to begin in May. The Ingolstadt company is firmly targeting the BMW 7-Series and Mercedes-Benz S-Class, although the much vaunted (and delayed) Jaguar XJ can't be rules out either.

The new car's development, which kicked off in 2005 has been nothing if not thorough. Under the A4-plus body, the aluminium spaceframe has been fully redesigned, and is usefully lighter than before, while inside, the interior has been revolutionised by a much-improved MMI interface, which not only features a laptop style touchpad for inputting place names (more intuitive than it might sound), but also has integrated Google Maps functionality. Again, this might sound like a gimmick, but on the move - it works very well indeed.

Although the outgoing car lacked nothing in terms of quality, the latest A8 feels just that little bit more premium. The seat design and colour schemes are muted and tasteful, and the interior abounds with delightful detailing that reminds you that you're in a flagship car: the MMI screens are gloriously hi-res and thanks to an NVidia graphics chipset it all animates flawlessly; the analogue clock is has an intricate 3D Audi emblem embossed into its face that must have taken serious development; the mood lighting is calming; and the input systems are delightfully tactile, and are blessed with consistent feel across the board.

Outside, it looks exclusive, too, albeit in an understated way. First impressions will be dominated by its LED headlights that feature no moving parts, but look closer and the laser-accurate shutlines will also impress the most fervent critic.

So, it's a good story all round? Well, pretty much yes, but the boot looks less usefully sized than before, and for those driving in the city, the bulky A-posts will obliterate the largest of cars at roundabouts...

On the move, the A8 delivers the goods - it weighs in at around 200kg less than its direct rivals - and thanks to a new eight-speed gearbox, it's even more responsive on the go. The on paper results are impressive, as a result: the 4.2-litre car that we tested puts out 199g/km, averages around 40mpg and gets from 0-60mph in 5.5 seconds. Top speed is limited to 155mph.

Responsiveness for keen drivers is blunted when in standard Drive mode as the gearbox takes on a smoothness-first programme, and the ride softens a tad more than the outgoing car, but stick it in Sport, the steering weighs up nicely, and it becomes an effective B-road weapon. Just remember that's it's still a large car. Get it on the motorway, and it's quiet and lopes along as you'd expect. There was some rustle around the A-posts, but that could have been an issue with this early-build car.

In conclusion, the A8 hits its intended targets square on - it's a great director's car that plays the role of limousine perfectly. Yet it also looks exclusive, as ample external jewellery, and has a sharpness that the old car now appears to lack. Whatever your thoughts on the effectiveness of the A4-plus styling, it sits naturally alongside the new BMW 7-Series and recent Mercedes-Benz S-Class, and has quietly shuffled to the head of the big saloon pack...