It's out with petrol and in with diesel as the new Audi S6 Avant boasts a 344bhp electrically assisted six-cylinder TDI unitVerdict4The Audi S6 Avant may lack some of the old car’s aural appeal, but it’s a much more rounded car as a result. It’s sharper to drive and almost as fast, yet will return far superior fuel economy and a truck-busting 600-mile range. It’s particularly tempting in Avant guise, too.
Audi’s evergreen S models are a varied bunch. Bookended by the athletic S3 and muscular V8-powered SQ7 TDI, the firm’s sporty S cars come in all shapes and sizes.
Yet despite the industry turning its back on diesel, Audi thinks the fuel still play a part in, of all places, the performance car market. As such, its latest S6 and S7 models have ditched their high-revving petrol engines in favour of an electrically assisted six-cylinder TDI.
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It’s a compelling proposition, and one that will surely still appeal to plenty of European buyers. The stats make for interesting reading: 344bhp, 700Nm of torque, quattro all-wheel drive and a 600-mile real world range. In S6 Avant guise, you also benefit from the standard car’s generous 565-litre boot.
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The S6 TDI uses a lightly modified version of the brand’s familiar V6 diesel engine, mated to a 48-volt mild-hybrid system and electric compressor. It’s a very similar set-up to the one used in the SQ7, albeit with two fewer cylinders and lower maximum power output.
While it might lack the old model’s V8 soundtrack, Audi has installed a sound generator to assure you and your passengers that this isn’t one of the firm’s humdrum S line models. It feels wholly un-natural however – we quickly switched it off using the car’s complex drive mode menus.
By effectively eliminating turbo lag, the S6 picks up instantly; plant your right foot and the Avant surges forward, building speed like Usain Bolt on a 200m World Record run. It never thumps you in the back like the old petrol engine did, but there’s no arguing that the way this car accelerates (0-62mph takes 5.1 seconds) could leave many a modern hot hatch for dead.
But the set-up is only as good as the gearbox that feeds it, meaning it can feel a little lethargic at times. Pulling away from rolling junctions or slow corners in third can catch the car out – in manual mode it won’t kick down either, leaving you frantically scrabbling for the left paddle, desperately searching for a lower gear.
It’s a shame, really, because our car’s four-wheel steering set-up makes the S6 incredibly agile – much more so than S cars of old. It’s an intuitive, progressive and natural-feeling system, as it should be, and allows the car to take a much tighter line than you might expect for an estate measuring almost five metres long.
Yet this car is arguably better suited to faster flowing roads and German autobahns. Here, the S6 excels; few cars are quite as capable at effortlessly swallowing three-figure distances in such impeccable refinement.
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Our test model featured the optional double-glazed front side windows, though in our experience that could be considered a little excessive. Our long-term A6 Avant 40 TDI was a supremely quiet cruiser, and we expect the S6 to be no different.
Of course, the cabin comes trimmed some of the finest materials. Up front there’s a set of supportive, electrically operated heated seats wrapped in Valcona leather upholstery – and quality doesn’t suffer for those in the back, either. The standard kit list is worthy of the Avant’s estimated £62,000 list price, boasting everything from four-zone climate control and keyless go, to Audi’s dual-screen MMI Navigation Plus infotainment system.
The 20-inch wheels give it presence, sure, but remove the badges and you’d be hard-pressed to pull this car apart from its standard S line or Black Edition siblings. Some might lament the S6’s delicate design, but to others its stealth styling will only add to its under-the-radar appeal.
- Model: Audi S6 TDI quattro Avant
- Price: £62,000 (est)
- Engine: 3.0-litre V6 diesel MHEV
- Power/torque: 344bhp/700Nm
- Transmission: Eight-speed auto, four-wheel drive
- 0-62mph: 5.1 seconds
- Top speed: 155mph
- Economy/CO2: 35.3mpg/171g/km
- On sale: June
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