Pay close attention if you want a glimpse into the future of Audi, writes Matt Joy. The top model in any range is the one that gets the most attention, the best engineering, and the finest the company has to offer.

Pay close attention if you want a glimpse into the future of Audi, writes Matt Joy. The top model in any range is the one that gets the most attention, the best engineering, and the finest the company has to offer. So the new A8 luxury saloon not only means that the top end of the market is about to get serious again, but also points to where all other Audis are headed.

The A8 is subtle but clean-cut and handsome, clearly more dynamic than the outgoing car but far from controversial, unlike some rivals. Some might wish for a more adventurous look, but Audi knows its market. Even on smaller wheels it looks good, but with the 20in versions it has great presence.

The A8 retains its aluminium spaceframe chassis, technology that was way ahead on the original A8 and still gives a significant weight advantage - more than 200kg compared to a steel chassis.

The A8 provides pleasure whichever seat you sit in. In the back, there's generous head and legroom and the cabin is luxurious and welcoming. There are endless toys to play with should you wish: go for the two-seat arrangement in the back and you can have massage seats with six different programmes (available in the front too), TV screens and so on, but standard power outlets show a practical side.

Up front the view out is better than ever. A sweeping dashboard brings more elegance to the cabin, and better frames the view ahead. Peerless quality is expected and delivered: the mix of leather, wood and various plastics and metals is tastefully done, with plenty of scope for personalisation. It makes you feel good, and has the robustness to stay that way for years.

There's some very clever new kit in here too. The sat-nav (with access to Google) talks to the new eight-speed gearbox, and will tell it to hold a gear rather than change up if there's a bend ahead. There's also night vision the new MMI touch pad. Audi's MMI system was one of the best solutions of controlling multiple functions, but the touch pad steps it up. It displays the units one to six for radio station presets, and requires a simple touch to change. However, if you're entering a sat-nav destination or searching for a contact in the phonebook, it becomes a character input device. Trace the letter you want, however crude your handwriting, and a voice repeats it back to confirm. It will accept Cyrillic or even Chinese characters.

On paper it's a sure-fire hit then, but it needs to translate to the road. There's good news within the first 10 yards however, as the steering reveals itself to be much more accurate, feelsome and sensitive than before. The superb ride quality also shines through in a matter of minutes, even on the 20in wheels, helped by the standard air suspension and the stiff bodyshell.

The engine line-up has been thoroughly refreshed too. There's 3.0-litre and 4.2-litre TDIs plus the 4.2-litre FSI V8, all of which offer more power and torque but with better fuel economy. The petrol offers a more than respectable 29.7mpg combined and 219g/km of C02 while still delivering a free-revving and sporty experience with a great soundtrack. Its lightness also makes it the most agile.

The 4.2-litre TDI now brings a kidney-crushing 580lb.ft of torque - hence the standard Sport differential in the Drive Select package - and a devastating combination of performance and economy: 37.2mpg, 199g/km of C02 and 0-62mph in 5.5 seconds.

The 3.0-litre TDI will be the most popular, bringing 42.8mpg and 174g/km of C02, with an even more frugal front-wheel drive version to follow. Although it can't offer the punch or ultimate refinement of the V8 diesel, it's still smooth, torquey and never fails to power the A8 with conviction.

Few cars so clearly demonstrate the lengths that its maker has gone to in order to create it. The new A8 is crushingly good in so many areas and hits the luxury car target right in the centre - it relaxes and cocoons its occupants like little else.

AUDI A8 4.2 TDI SE

PRICE: �63,690

ENGINE: 4.2-litre, 345bhp turbo diesel delivering 580lb.ft of torque

PERFORMANCE: 0-62mph 5.5 seconds; top speed 155mph

MPG: 37.2mpg combined

EMISSIONS: 199g/km