New 420bhp A8 L 6.0 quattro offers unparalleled blend of potency and refinement

For the first time since 1932, an Audi will be powered by a 12-cylinder petrol engine which will write it into the record books as the world’s most powerful production saloon. The revolutionary 6.0-litre, 48-valve unit has a unique ‘W’ cylinder layout and a mighty 420bhp power output, and creates a new flagship A8 model - the A8 L 6.0 quattro - which goes on sale in Germany this month costing the equivalent of £70,000.

Notable as the first ever production car to offer the benefits of lightweight all-aluminium construction, and the only luxury saloon to provide the reassurance of quattro four-wheel-drive, the Audi A8 also now boasts unrivalled performance from the most powerful twelve-cylinder engine the world has ever seen.

The fusion of two ultra-compact aluminium block V6 engines has created the awesome 6.0-litre W12, delivering 420bhp and a colossal 550Nm (405lb ft) of torque. It is capable of powering the new A8 L 6.0 quattro from rest to 62mph in just 5.8 seconds, from rest to 124mph (where conditions allow) in a mere 20 seconds and to an electronically limited 155mph top speed in only 38 seconds. Despite this incredible performance it also complies with EU 4 emissions limits, due to come into force in 2005, thanks in part to its six three-way catalytic converters

Unique engine design

Audi is the only manufacturer to use a twelve-cylinder engine arranged in a double ‘V’ or ‘W’ formation in volume production. The block from each V6 unit, containing six cylinders mounted at an angle of 15 degrees, is linked together at an angle of 72 degrees to form the ‘W’.

The major benefit of this unique design is its space efficiency - in fact, despite additional cylinders and a larger displacement, the 6.0-litre W12 engine actually takes up no more space than the 4.2-litre V8 engine which sits just below it in the A8 range.

The advanced design, combined with the extensive use of aluminium components, has permitted an exceptionally low engine weight of just 245kg. Thanks also to the A8’s aluminium body construction and Audi Space Frame (ASF) technology, the overall kerb weight of the A8 L 6.0 quattro is just 1,980kg, significantly lower than any comparable car.

Uniquely quattro

Another major advantage of the W12 unit’s compact size is that it enables power to be transmitted, via the standard five-speed tiptronic gearbox, to all four wheels, bringing obvious benefits in traction and control. All other conventional front-mounted V12 engines drive only the rear wheels because there is normally insufficient space within the engine bay for the additional components.

A new Audi flagship

To create the ultimate luxury Audi, the W12 engine has been installed in the long wheelbase version of the A8, which is 130mm longer than the standard car and provides rear seat passengers with an impressive 70mm of extra legroom, plus additional head, elbow and shoulder room.

Signifying its position as the flagship of the Audi range, the new A8 L 6.0 quattro features a unique radiator grille design with vertical chrome bars and a discreet W12 emblem, which is also to be found on the side rubbing strips and, inside the car, just above the glove box. It is also given added road presence by 18-inch, 10-hole alloy wheels with 245/55 ZR 18 tyres.

Specification obviously befits this car’s credentials, and as usual safety features are comprehensive. Fitted as standard are front airbags for the driver and front passenger and side airbags for all outer seat occupants, plus the SIDEGUARD head airbag protection system, which covers almost the entire side window area in the event of a side impact. The Electronic Stability Programme (ESP) also backs up the quattro four-wheel-drive system, giving maximum driver control.

The W12 engine, in common with Audi’s equally spectacular V8 TDI unit, will not be fitted to right-hand-drive versions of the current A8 saloon, but will form part of the UK line-up of future generation A8 models.