EIGHT cylinders, four driven wheels, one new body style, no half measures - the mould-breaking saloon version of the all-new V8-powered Audi RS 4 quattro saloon opens for UK order on Wednesday, March 30, with an on-the-road price of £49,980 for first deliveries in October.

The first B segment Audi RS Saloon is also the first Audi model to combine eight-cylinder power with FSI direct petrol injection for optimum efficiency.

The naturally aspirated 4.2 litre V8 petrol engine is good for 420PS in the RS 4 quattro, equating to a highly impressive specific output of just over 100PS per litre, combined with maximum torque of 430Nm at 5,500rpm, 90 per cent of which is available from 2,250rpm all the way to 7,600rpm.

The exceptionally free revving character of this latest Audi V8 is no less impressive, the rev counter needle spinning all the way to 8,250rpm through the manual transmission's six ratios to provide breathtaking acceleration from rest to 62mph in just 4.8 seconds. Autobahn permitting, a sprint from rest to 124mph is possible in only 16.6 seconds on the way to an electronically limited top speed of 155mph.

For maximum exploitation of the remarkable new engine, weight has been minimised through the extensive use of aluminium for normally heavy items such as the suspension, bonnet and front wings, and through detail changes including the installation of ultra-light RS bucket seats.

These changes help to maintain a very impressive power-to-weight ratio of 254PS per ton.

Throttle response can be maximised at the touch of a special Sports button mounted within the steering wheel that adjusts the throttle control mapping when particularly sporting driving is 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.

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 responsibly. 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.

Riding on unique 19in alloy wheels framing immensely capable 18in 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 engine starter button, tapered sports steering wheel, aluminium pedals and black metallic Valcona leather-upholstered RS bucket seats with electrically inflatable side supports combine with extensive carbon fibre trim to create a fittingly sporting atmosphere.

Exclusive RS 4 quattro standard equipment also includes cruise control, front seat heating, a BOSE sound system, front and rear acoustic parking sensors and electronic tyre pressure monitoring.