GoAuto 01/09/2006

AUDI’s RS4 is the sort of car that burns itself your inner hard drive with such intensity that it just about wipes everything else from memory.

Recollections of faultless, towering power delivery, rock-solid stability and mighty brakes replace a program once written by Porsche’s 911.

All this resides in a tightly packed, compact sedan body with just enough room for four people who would probably just as soon be there as waiting to be rocketed skywards in a space shuttle.

On paper the Audi RS4 sounds spectacular.

4.2-litres of direct-injected V8 producing a thundering 309kW, an all-up weight of 1650kg, full-time four-wheel drive and a manual-only six-speed gearbox mean acceleration times that eclipse a Porsche 911 Carrera.

Four-wheel ventilated and cross-drilled disc brakes grab the little projectile by the scruff of the neck and haul it back from the blistering speeds of which it is capable, while Audi’s brilliantly simple Dynamic Ride Control system keeps it sitting flat whether cornering hard, braking hard or accelerating hard – all things the RS4 is wont to do.

No other car in recent memory delivers a drive experience as scintillating and addictive.

The multi-faceted accelerative performance is marked by the ability to rumble along slowly and smoothly one minute, step up to a head-rushing pace the next, then launch into orbit-insertion mode a moment later.

In any of these modes the RS4 feels right at home, as responsive to the accelerator as if turning on a tap and delivering a delicious, thrilling rumble that can be made even more so by thumbing a small switch in the left-side steering wheel spoke.

It’s a car of ongoing sensory input that, if you have any love of driving, never fails to thrill.

Developed from the already nimble and tightly packaged A4, the RS4 is the latest in a line of RS Audis that is fast being written into folklore.

Some say their favourite RS4 was the twin-turbo V6 wagon from 2000-2001, but it’s doubtful anybody would feel that way after a little time in the latest version – which will also become available in wagon and cabriolet forms.

No turbochargers here: just a high revving, normally-aspirated alloy V8 that delivers a power-to-weight ratio way in excess of just about anything else other than a stratospherically expensive and fragile exoticar.

Developed from the compact V8 seen in the S4 model that blew us all away in manual form from 2004, but was somewhat emasculated by the decision to go auto-only at the end of its life here, the 4.2-litre engine has been given things like modified pistons and conrods, a new crankshaft, new cylinder-heads and the big-bore twin exhaust to awaken it to its full 309kW.

It is capable of spinning to comfortably more than 8000rpm while churning out 90 per cent of its 430Nm torque maximum from 2250rpm. It’s still producing meaningful twisting power at an astronomical 7600rpm, which correctly indicates it’s not lacking flexibility.

No other engine comes to mind that is as multi-dimensional as the RS4 V8. Like we said, it’s deeply suggestive but perfectly tractable at low speeds, heavily muscled in the midrange and becomes a screeching, manic, banshee-wailing monster in the upper reaches.

All the while this is being calmly managed by an expertly engineered mix of electronic controls and some really clever physical engineering.

BMW-like, the RS4 is replete with acronyms including FSI (direct petrol injection), DRC (Dynamic Ride Control), ASR (traction control), ESP (Electronic Stability Program) and EDL (Electronic Differential Lock) that generally look after the car under an emergency or if things start to go awry.

These are only some of the electronic programs working away quietly in the RS4 and they are supported by a chassis that tends to do things properly in the first place.

It uses full-time 4WD complete with a self-locking Torsen centre differential that normally operates on a 40 (front) 60 (rear) basis but is able to direct power wholly to either the front or back ends if necessary.

The RS4 sits 30mm lower than a regular A4, on wider tracks and oversize 19-inch wheels shod with 255/35 R19 tyres.

These, really, are the main identifiers of this car that generally lets its spectacular performance speak for itself moreso than overdone bodywork.

Only the deep and meaningful air-vents flanking the full-frame grille, the small spoiler worked into the bootlid, dual oval tailpipes and restrained side skirts substantially separate it from other A4s.

It’s possible to trick up even a base 2.0-litre Audi to look much the same, but the RS4, complete with its aluminium bonnet and front wings, is the real thing.

A downside of the massive wheels is that there’s no spare here, just tyre pressure monitors and a "repair system" in the boot.

The RS4 is all pretty focussed inside, with a flat-bottom steering wheel sporting some surprisingly tacky fake-alloy plastic inserts, real-alloy floor pedals and footrest, and a set of fair dinkum sports seats with side bolsters so big you almost need climbing gear to get over them (to take it even further, if these aren’t already enough, Audi offers "Sports" seats as an option).

Press the button on the steering wheel and the standard seats automatically clinch even tighter to give you a sense of security when you reckon it’s time to get serious, while also bumping up the volume of the dual exhaust system to make it a car of aural, as well as physical delights.

The deeper bass of the exhaust is indicative of nothing other than the fact you’re fond of a bit of V8 feedback, although Audi says the accelerator response is quicker. Whatever, it’s unlikely you’ll ever drive an RS4 and knowingly leave the exhaust in "quiet" mode.

There’s plenty of standard gear too, including satellite-navigation, see-around-the-corner Xenon headlights, front and rear park-distance sensors and a 10-speaker Bose sound system (if you can be bothered trying to drown out the V8), as well as a full supply of airbags (dual front, dual side at front and rear as well as a full-length curtain) and active, whiplash-protective front head restraints. But you don’t get power seats up front, and you’ll need to dig deeper to get a sunroof.

What can we say about the Audi RS4 other than it’s as decisively capable as it is almost sentient?

The car is alive, eager and irresistibly athletic. Not many drivers will be capable of exploring its limits, and then this is only likely to happen on a racetrack.

And, because of the full-time 4WD, there’s more than normal grip on greasy roads - although here you’re best advised to leave the specially configured ESP switched on. It can be deactivated in two stages – the first cancels the traction control, the second stage switches off all ESP functions – but this is only recommended where you’re sure of what you’re about.

Like the suspension, the steering has been specially tuned for the RS4 and it’s certainly quick, crisp and nicely informative with just-right weighting at the wheel rim.

Likewise the brakes, which are big, light, perforated and ventilated, and use eight-piston fixed callipers with four pads at the front, along with single-piston single callipers at the rear. These are cooled by NACA jets that direct airflow to keep the system as cool as possible and have a dry-braking function to sweep the discs dry with regular light pad contact when it’s raining.

All this means is that the RS4 has the wherewithal to appropriately contain what amounts to a massive engine in a relatively small body. The power-weight ratio of 187kW per tonne speaks for itself. That’s approaching the sort of figure you expect in a Ferrari.

The clincher is in the price. $165,500 is a lot more than your regular 2.0-litre A4, but it’s a hell of a lot less than you’d need if you look elsewhere for the same performance levels.

For now, the RS4 certainly kicks BMW M3 butt.