The fourth generation of Audi’s S-badged A4 scores an all-new engine to complement its new-generation platform.
WHAT IS IT? The first proper performance variant in Audi’s all-new B9 A4 range, available in both sedan and Avant wagon guises, tied exclusively to a new eight-speed automatic transmission.
WHY WE’RE TESTING IT? Unveiled at last year’s Frankfurt motor show, Audi appropriately launched its subtle new S4 stormer in the hills surrounding the same city. Given the deeply impressive ability of the lesser A4 that (literally) sits under it, the new S4 promises to be a sizeable step forward from its well-liked, supercharged predecessor.
MAIN RIVALS BMW 340i, Jaguar XE S, and Mercedes-Benz’s forthcoming twin-turbo V6 AMG C43 (due November).

PLUS: Benchmark interior quality and design; excellent grip; poised chassis; brisk performance MINUS: New engine acoustically inferior to previous blown V6; optional dynamic steering doesn’t feel natural; lumpy ride

On paper, the differences aren’t so obvious. The new S4’s all-aluminium 90-degree V6 shares its bore and stroke, and thus its 2995cc capacity, with its supercharged predecessor, but that’s where the similarities end. Different bore centres, a new two-phase combustion method with centrally mounted high-pressure fuel injectors, and a twin-scroll turbocharger mounted inside the vee has produced a more compact, lighter (by 14kg), friction-optimised engine with enhanced response, higher outputs and improved efficiency.
Power jumps from 245 to 260kW, while torque swells to a solid 500Nm from 1370-4500rpm (up from 440Nm at 2900-5300rpm). The previous S4’s seven-speed dual-clutch transmission has been replaced with an eight-speed torque-converter automatic and the S4’s 0-100km/h claim drops to 4.7sec.

The new eight-speed auto seems to match the previous dual clutch’s shift speed, while being smoother in traffic with a slick idle-stop system, and it features a freewheeling mode that saves fuel when coasting in Drive between 55 and 160km/h. If the combined fuel figure isn’t complete porkies, 7.5L/100km isn’t to be scoffed at.

There’s a marked difference between the throttle response in the transmission’s Drive and Sport modes, despite the sweet spot being somewhere in between. The S4’s accelerator feels almost resistant in Drive and demands lots of pedal travel to deliver what you’re asking for, while Sport is far too twitchy and throws passengers around when stepping on and off the right pedal.

The new-gen S4 definitely handles – especially when enhanced by the razor-sharp turn-in of optional dynamic steering – but it doesn’t ride. Even in the adaptive dampers’ comfort mode, there’s an unsettled knobbliness to the S4’s ride (on Hankook Ventus S1 Evo 2 245/35ZR19 tyres expected to be standard in Oz) that is at odds with the regular A4’s plush composure.

Mechanical gripes aside, there’s a lot to like about the new S4. Its interior is fabulous, including a new screen in the Virtual Cockpit display that shows the tacho dead-centre with a digital speed reading inside, and the optional head-up display is arguably the world’s prettiest. Both bodystyles blend subtly sporty looks with practical elegance, and the S4 has great brakes – 350mm front discs with six-pistons calipers and very natural pedal feel.

Audi hopes the new-gen S4 will make up three to five percent of total A4 sales, as opposed to the current car’s one to three percent. But we can’t help thinking the sweet spot is at A4 level, in 185kW 2.0-litre turbo quattro guise. Until the S4 receives attention to its ride and its engine acoustics, its baby brother remains supreme.
SPECS Model: Audi S4 quattro Engine: 2995cc V6 (90°), dohc, 24v, turbo Max power: 260kW @ 5400-6400rpm Max torque: 500Nm @ 1370-4500rpm Transmission: 8-speed automatic Weight: 1630kg 0-100km/h: 4.7sec (claimed) Fuel economy: 7.5L/100km (EU) Price: $107,000 (estimated) On sale: October