AN all-new V8-powered evolution of the widely acclaimed RS 4 quattro will dominate the Audi stand at the 2005 Geneva Motor Show, remarkable as much for its saloon body shell as for its awe-inspiring capabilities.

The first ever B-segment Audi RS saloon epitomises Vorsprung durch Technik through numerous advances including an unprecedented combination of eight-cylinder power and FSI direct petrol injection and a new generation of quattro four-wheel-drive technology.

At the heart of the RS 4 quattro is a naturally aspirated 4.2-litre V8 FSI petrol engine that delivers 420PS, equating to a highly impressive specific output of just over 100PS per litre.

Maximum torque of 430Nm occurs at 5,500rpm, and 90 per cent of this peak is available from 2,250rpm all the way to 7,600rpm, though the exceptionally free revving unit is actually capable of powering on well beyond this to 8,250rpm to provide breathtaking acceleration.

The 0-62mph sprint is dispatched in just 4.8 seconds, 124mph from rest on a suitable Autobahn can be seen in only 16.6 seconds and an electronically limited top speed of 155mph is easily achievable.

FSI direct petrol injection, which cut its teeth in the V8-powered Audi R8 Le Mans racers before filtering into four and six-cylinder Audi road cars, appears for the first time in a road-going Audi V8, helping to maximise both performance and efficiency through even more effective and accurate fuel combustion.

Numerous special measures ensure that this remarkable new engine is not only safely contained but also given the freest rein possible.

For maximum exploitation of its potential, a Sports Button mounted within the steering wheel enables the driver to adjust the throttle control mapping to give even sharper throttle response when required.

The Electronic Stability Programme (ESP) has also been reprogrammed to intervene later and for a shorter period than it normally would in a standard A4, ensuring that control is always maintained but driving satisfaction is maximised.

In addition, special care has been taken to avoid dulling the performance through excess weight.

An impressive power-to-weight ratio of 254PS per tonne has been achieved through the extensive use of aluminium for normally heavy items such as the suspension, bonnet and front wings, combined with other detail changes including the use of ultra-light RS bucket seats with electrically inflatable side supports.

Sitting 30mm lower than a standard A4, and with a wider front and rear track, the new RS 4 quattro is equipped to deliver highly rewarding handling without the 'heart-in-mouth' moments to which some high-powered super cars can be prone.

A new evolution of the renowned quattro four-wheel-drive system able to transfer a larger proportion of torque between front and rear axles, makes for even more adjustable cornering behaviour.

The system works in conjunction with Dynamic Ride Control, an electronically governed, mechanical damping system adopted from the RS 6 quattro.

DRC connects shock absorbers on each side of the car diagonally to their counterparts by way of a central valve, which directs a flow of oil to provide additional damping force whenever a shock absorber is compressed, making for impressive gains in handling precision and stability.

Riding on unique 19-inch alloy wheels framing immensely capable 18-inch disc brakes, and fronted by the latest Audi single frame grille, the attention-grabbing body of the new RS 4 quattro cloaks an equally dramatic interior.

Its tapered sports steering wheel, RS bucket seats and engine starter button combine with extensive carbon fibre trim to add more than a touch of racing car purpose without diluting the comfort, quality and exceptional attention to detail for which Audi interior design is renowned.

Pricing and full specification for right-hand-drive versions of the new RS 4 quattro, which will be available in both saloon and Avant estate body styles (Avant from 2006), will be announced closer to its UK launch in spring 2005, ahead of first customer deliveries in autumn 2005.