The 4.2-litre V8 is one of the great road car engines of the moment. At 1500rpm in sixth gear there is real urge on offer, yet it sounds and feels sensational at high revs in low gears and delivers the sort of thump only supercar drivers will have been familiar with. Its very best work occurs from 5000rpm upwards: the cam phasing changes slightly, the exhaust note hardens and the acceleration crystallizes into one final burst towards the cut-out.
That engine is linked to a six-speed gearbox whose ratios are just about perfectly chosen and whose shift action is short and light, if a little notchy.
The Audi thunders to 60mph and 100mph in just 4.5sec and 10.5sec respectively, taking care of the M3 (4.8sec, 11.5sec) en route. All the third-gear timings were dispatched within a whisker of 3.0 seconds, be that at 30mph or 100mph. An M3 cannot compete with the RS4’s relentless wave of low- and mid-range flexibility, even if it is marginally more explosive over the final few revs before the limiter.
The RS4 still doesn’t have the same clarity of response or steering communication as an M3 or a Porsche 911, but it has more than enough to make it a genuinely rewarding car to drive.
The ride is so good over poor surfaces you wonder how Audi got it so wrong for so many years. It controls its body so precisely across uneven cambers and changes direction properly. The steering is extremely accurate, allowing you to place the nose where you want through most corners with nothing more than a whiff of understeer to warn you that the laws of physics are beginning to overwhelm the enormous limits of the tyres. The brakes do an admirable job of coping with all that potential on the road.
At the track, the RS4 posted a dry lap time to match that of the Porsche Cayman S, which is no small achievement. Our only concerns were brake fade and the increasing onset of understeer as the tyres get hotter; after four laps the RS felt as if it had had enough. But the Audi is a road car.
