On an Audi, the letter stands for all of these things, combined with the company’s trademark quattro four-wheel drive to provide a performance and roadholding package that ranks with the best on the planet. Applied to the latest-generation A4 platform, it also means a 4,2-litre V8, ingeniously engineered into the compact saloon’s (or wagon’s) tight engine bay. The ploy used to make it fit is a new timing chain design at the back of the power-unit, which has lopped 52 mm off the overall length…
The new Audi S4s, in saloon and Avant station wagon guises, have just become available in South Africa as Audi responds to the success in this market of the BMW M3 and Mercedes-Benz C32 AMG. And, as with its fellow Teutons, understatement is the name of the styling game – apart from the dramatic yellow colour scheme of the saloon version provided for our first test.
Paintwork aside, the car’s performance credentials are conveyed by subtle detailing. The headlights are xenon units, there’s a vestigial lip-spoiler on the trailing edge of the bootlid, the 18-inch Avus alloy wheels are shod with 235/40 Contis, distinctive black “S” side strips underline the doors, wide diameter twin exhausts exit at either side of a splitter-like inlay on the rear valence, and those trademark aluminium housings for the exterior mirrors glint as the light plays on them. The lower front air intakes are larger, and the black grilles contrasted with the test car’s bright paintwork, giving the front end a touch more overtaking presence. Otherwise, it’s pure A4, with all the passenger and luggage capacity of the ordinary saloon.
Of course, under the Q-car exterior, the new S4 is quite extraordinary. Starting with the “trimmed” normally aspirated V8. Apart from its shorter length, thanks to the use of lightweight materials for items such as pistons and connecting rods, the eight-pot is also extremely light, weighing in at 195 kg.
In fact, its mass is almost identical to that of the twin-turbo 2,7-litre V6 that did duty in the previous-generation S4. It features twin overhead camshafts per bank actuating five valves per cylinder, displaces 4 163 cm3 and delivers peak outputs of 253 kW at 7 000 r/min and 410 N.m at 3 500. True to quattro tradition, the four-wheel drive system features a self-locking Torsen central diff that apportions torque between front and rear axles. Drive from the engine is via a six-speed manual gearbox.
Suspension is similar to that of other A4s, but the S rides 20 mm closer to the tarmac, and springs, anti-roll bars and shockabsorbers have been retuned in line with the car’s sportier aspirations. Brakes are ventilated discs (340 mm diameter fronts, with the rears measuring 300 mm) and there’s the full range of driver aids, including ABS, EBD, BAS and (switchable) ESP.
Inside, the cabin has a typically sombre air, with the usual dark high-quality Audi plastics for dash and door-cappings, trimmed in this instance with carbon-fibre-look inserts. Instrumentation is clear, with white-on-grey analog dials for speedo and tachometer, and controls are ergonomically perfect. SA-spec S4s come with electrically adjustable sporty Recaro front seats with leather side-bolsters and suede-feel Alcantara facings. A full range of adjustment, including one for cushion height, allows the driver to achieve a perfect viewpoint, and the wheel is adjustable for height and reach. The chairs are comfy and supportive, but the Alcantara tends to grip the clothing if one moves while seated. Legroom in the rear is tight, but the rear bench is comfy for two. The boot offers 400 dm3 of primary luggage space, and the split rear seatback folds down to provide load bay of over 1 072 m3.
While performance is the Audi S4’s primary raison d’étre, it’s no stripped-down sportster. All the usual luxury features are standard, including a premium radio/CD (no remote on the sports wheel, though), climate control, electric windows, electric mirrors, trip computer, satellite navigation, central locking and remote alarm/immobiliser. Passive safety equipment includes a full range of airbags – front, side and curtain units – as well as seatbelt pre-tensioners. The A4/S4 platform achieved four stars in the Euro NCAP crash test programme.
Though the lightweight motor goes some way to counter the mass penalty of the quattro system (not to mention items such as those electric seats), the steel-bodied S4 is a heavy car, weighing in at 1 767 kg in test trim, but the 253 kW V8 ensures electrifying performance. Surging forward strongly from 1 000 r/min onwards, the unit really comes into its own from 5 000, snapping you back in your seat as it spins towards the soft limiter, which cuts in at around 7 300 r/min. Out on our test strip, with traction control switched out, the test unit chirped all four Contis off the line before sprinting to 100 km/h in 5,79 seconds. It stormed past the kilometre mark in 25,55 seconds (at 208,8 km/h) and went on to record a top whack of 265 in sixth gear before the limiter – ostensibly supposed to cut the spark at 250 km/h – intervened. That makes the S4 the fastest four-door saloon tested by CAR to date…
Aiding the rapid forward momentum is a meaty but slick gearshift, and the ability to exceed 100 km/h in second. Stopping is no less impressive, the four-wheel ventilated discs pulling the test car up in an average of 2,88 seconds in our standard 10-stop 100-to-zero braking test.
But, while the straight-line figures are impressive, where the S4 excels is in point-to-point performance on a twisty road. The steering lacks some feel around the centre point, but once you’re turning in it becomes more communicative.
Really overdo it, and the car will understeer, but grip levels are so high that only crass behaviour will bring in the ESP in dry conditions. But, if you’re over-zealous in the wet, it’s there to add to the security provided by four-wheel drive.
In fact, with the stability and grip provided by the quattro system, you don’t need exceptional skill to drive the car very rapidly indeed. In the hands of Mr Average, few vehicles will match the S4 on a cross-country dash, particularly in wet weather. The trade-off is a firm ride, firmer than aficionados of the marque might expect, but reasonable in a performance saloon.
High body mass takes its toll on fuel economy, the test car recording a CAR index – our estimate of fuel thirst in enthusiastic driving – of 13,26 litres per 100 km. So drivers who use the car’s prodigious performance are unlikely to manage more than 500 km on a 66-litre tank of fuel.