The S4 slips effortlessly into the dynamic space occupied by the vast majority of fast Audis: its quattro four-wheel-drive system, chassis and steering all work together to harmoniously, if a little coldheartedly, deliver a level of security, drivability and point-to-point pace – regardless of the prevailing weather conditions – that few rival performance saloons can match.

However, where many of its range mates maintain their sense of steely, overly serious determination at all costs, the S4 is capable of letting its guard down for brief moments. With its stability systems reduced and a heavy application of throttle on corner exit, fleeting instances of tail waggling can be coaxed out of the otherwise steadfastly inert S4.

Matt Saunders Autocar

Matt Saunders

Road test editor
V6 diesel engine’s immense torque reserves endow it with incline-levelling amounts of acceleration out of corners

The car doesn’t hold a candle to the new BMW M340i xDrive in terms of expressive adjustability (which, even in prototype form, proved a wieldy, highly engaging performance saloon), but even a modest sprinkling of dynamic liveliness is nonetheless welcome.

The S4’s steering, meanwhile, is direct but typically tight-lipped. With 2.25 turns between locks, it lends the Audi a suitably responsive front end, although it doesn’t bode particularly well for the S4’s ability to engage that the passive system fitted to UK cars should make for a slightly gentler and lighter-feeling tiller. For what it’s worth, the Dynamic set-up proved well weighted and as capable of filtering out bump steer and other corrupting influences as you’d expect of a modern fast Audi.

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Body control is very good. Even with the S4’s adaptive dampers in their slackest setting, they kept lateral roll tidily and progressively checked and contributed to the sense of unerring confidence the S4 imparts when driven swiftly.

Driven hard on Millbrook’s challenging Hill Route, the S4 was seriously quick. The V6 diesel engine’s immense torque reserves endowed it with incline-levelling amounts of acceleration out of corners and the grip and stability afforded by its chassis allowed impressive speed to be carried through them, too.

Surprisingly, though, the S4 wasn’t so composed that it lacked a sense of humour. Backed into sharper bends on the brakes, it would willingly begin to rotate. The same effect could also be achieved by burying the throttle on the exit of the corner.

Even with the stability systems left on, progress around the circuit was fluid and unimpeded, with only the most severe compressions forcing them to step in and restrict progress. At pace, the Dynamic steering took a bit of time to acclimatise to, but once dialled in, the quickened response when travelling at pace proved entertaining.

COMFORT AND ISOLATION

Our S4 TDI was fitted with adaptively damped S sport suspension, which will be available on only forthcoming Vorsprung models in the UK. So equipped, there’s a noticeably firmer edge to the primary ride than you might expect, but this isn’t so pronounced as to make the car uncomfortable or taxing to drive.

Even in Comfort mode, there is a fairly stern air about the S4’s vertical body control that allows it to handle undulating surfaces in a manner that feels taut and purposeful but isn’t so unforgiving as to give the base of your spine much trouble. Secondary intrusions are felt moderately keenly when crossed at town speeds, but again the severity of such impacts doesn’t seem grossly out of step with what you’d expect from the average performance saloon. If anything, they surprise you only very slightly from an Audi S car.

Greater pace improves the S4’s ride and reinforces the impression that this is a car more suited to quickly dispatching vast distances on Britain’s motorways and dual carriageways than being thrashed down your favourite B-road. Combine this dynamic confidence with a comfortable driving position and a hushed, refined powertrain and the result is a formidable long-distance tourer.

Formidable but not quite perfect. While the engine is certainly demure at a cruise, the 19in alloy wheels and tyres do generate a noticeable amount of roar on Britain’s at times coarse road surfaces. At a sustained 70mph cruise, our sound gear measured cabin noise at 70dB.

Admittedly, that’s not terrible, but the 320d we road tested earlier this year (which ran on lowered M Sport suspension and 18in wheels) returned a reading of just 64dB in the same conditions.

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