BY TIM BRITTEN | 2nd Jul 2004
More recently, and in a form more accessible to mortal drivers, the S-badged Audis have been giving BMW, which seems to have cornered the market for desirable and accessible high-performance road cars, a run for its money.
The recently introduced RS6, which is faster than a Porsche turbo, rates as one of the world’s most desirable sedans – although its $220,000 price tag maybe makes less than accessible to most.
The A4-based S4 V8 is the latest S version to arrive here and, at about $90,000 cheaper than the thundering RS6, is a bit more reachable.
The previous S4 was something of a phenomenon itself, what with 2.7 litres of 195kW twin-turbo V6 producing 400Nm of torque – and delivering it to the road via full-time 4WD.
In a car the size and weight of an A4, 4WD proved an expedient solution to the problem of putting all that power effectively onto the ground.
The new, 4.2-litre V8 S4 raises the possibilities to an almost astonishing level.
With no less than 253kW and a hulking 410Nm of torque, the 1660kg Audi rates as one of the remarkable new releases of 2004, not that far behind the RS6 in terms of power-weight and all the more impressive because all the grunt comes without the aid of turbocharging.
The twin-turbo, also 4.2-litre RS6 – which is only available as an automatic – reaches 100km/h in 4.7 seconds where the auto S4 (remember it’s a lot cheaper than the bigger car) gets there in 5.8 seconds. The six-speed manual version tested here gets there even quicker, in 5.6 seconds.
The concept of cramming an efficient 4.2-litre V8 – it’s the same capacity as the larger of the two engines available in the flagship Audi A8 – into a car most commonly powered by a 2.0-litre four-cylinder engine is quite outrageous.
In fact, the Audi only works as a road car because of its 4WD system. It’s not too difficult to imagine a front-drive S4 being anything else but undriveable.
With a network of computerized aids to help deliver the torque where it’s best utilised, as well as a AWD system that incorporates a Torsen torque-sensing centre differential, there is - believe us - rarely a problem with traction.
In fact, the system is so good it even allows the thundering V8 a little wheelspin on full-bore takeoffs to avoid bogging down and maximise the acceleration.
The V8, so easily able to cope with the S4’s weight, spins almost as freely under load as it does without. Nudge the accelerator, at any reasonable speed, and the S4 morphs from a slow speed to a higher speed without noticeable hesitation.
And it doesn’t appear to matter what gear it’s in. It will virtually idle up steep hills at 70km/h in top gear, making the sextet of ratios seem almost redundant.
Hammer it, and there are not many cars able to match its dizzying charge off the line. In fact, the S4 feels a lot faster than the already impressive figures indicate. The exhaust note, from inside the cabin, is quite muted, murmuring its V8 beat with an almost disappointing discretion.
From the outside, a redline run will be accompanied by a rasping blast from the twin tailpipes as the car rapidly disappears from view.
The six-speed manual transmission offers nice close ratios and a reasonably slick shift pattern, although the driveline itself is a little snatchy. Smooth changes only come with concentration.
Fitting the long-stroke (which helps torque as well as reducing block length) engine into the A4 would not have been possible without the redesign that saw it being shortened by moving the ancillary (now chain-driven) drive gear to the back of the engine, which cut the length, compared with the existing 4.2-litre V8 seen in the A8 and A6, by a respectable 52mm. But it’s still a tight fit.
Audi also says the new engine – also seen in the just-released Allroad V8 – weighs the same as the previous S4’s twin-turbo V6. This has obviously helped with the power-weight ratio as well as the car’s overall balance.
The S4’s suspension is a lower-riding (by 20mm), specially tuned version of the all-independent, heavily alloy-dependent system used in A4s. Springs, shock absorbers and anti-roll bars have all been tightened up so the chassis is able to contain the power, while the steering ratio has also been quickened to give sharper response.
The wheels are pretty serious too, although in keeping with the general restrained approach evident throughout the S4, they don’t go overboard. The 18-inch "Avus" alloys are only seen on the S4 and are wrapped in sporty, but not excessive, 235/40R18 tyres.
The result is a car that rides pretty much as you’d expect from something with the potential of the S4. In general terms it tends towards a certain pitchiness, although it is not harsh.
It absorbs small bumps quite okay, and there’s no noticeable bump steer (in which the car is deflected as the wheels encounter irregularities in the road surface) to contend with, but it could never be described as relaxing.
Considering the performance, it’s a small price to pay.
The S4 handles appropriately for its performance, maybe not sitting as tight and flat as a BMW M3, but predictable, tenacious and confidence inspiring nonetheless.
Rarely will the S4 be seen at its limits – the standard electronic stability control (ESP) is always there to step in and keep things in hand when necessary anyway.
As if all-time AWD was not enough, the S4 also gets an electronic differential lock and traction control, as well as the usual four-channel anti-lock with brake assist and electronic brakeforce distribution.
The brakes themselves are special too, with larger, ventilated discs front and rear, as well as a new dual-rate servo that increases the boost above 0.5g of deceleration to increase stopping power without bringing the driver out in a sweat. The pedal, thankfully, doesn’t feel over-sensitive in the fashion once noticeable in Audis.
The S4, perhaps slightly disappointingly, doesn’t look hugely different to regular A4s. On the bootlid, there’s the tiniest of spoilers and the doorsills are body coloured. The exterior mirrors get a faux alloy paint job and the front and rear bumpers are body colour. That’s about it.
Inside there’s a set of body-grabbing, Recaro seats – front and rear - trimmed in combination leather and cloth, and power-adjusted at the front (although there’s no driver memory).
There’s a three-spoke leather steering wheel as well as the almost predictable splash of carbon-fibre around the dash and doors (birch grey, aluminium grey or black piano finish are optional). The instrument cluster gets the grey dials and special needles familiar in Audi S models.
Otherwise the interior is straight Audi A4 comfortable and reasonably spacious in the front but rather tight in the rear. The boot will hold up to 445 litres of luggage, which is pretty handy.
The burning question concerns how the S4 shapes up against the similarly priced BMW M3.
In a way, both are quite different cars – the BMW a focussed sports coupe with a raspy, hard-edged and highly worked six-cylinder engine and the S4 a more tractable, easy-to-live-with high performance sedan. With four doors.
Facing such a choice would be a wonderful dilemma.