Audi decides that its S models should have big-hearted diesel power, which - in the current climate of backlash against the fuel - might look risky. But when you drive something as complete as the new S6 Avant, it's hard to argue with what the German company has pulled off.
In the Metal:
Has there ever been a big, sporty German estate that's looked anything less than magnificent? Answer: no, there hasn't, so stick the S6 Avant down on the long list of hugely desirable wagons that have issued forth from Germany. Sure, you can have your S6 in saloon guise, but why you'd want to do that (apart from the fact that the four-door model is lighter, so it's slightly quicker for 0-100km/h - 5.0 seconds - and it slips into a lower band for road tax, equating to €570 per annum) is beyond us. The S6 Avant is denoted by 20-inch alloys, meatier lower body styling, big air intakes and, on the estate, a lovely roof spoiler that enhances its presence that bit more. About the only bum note (literally) are those quad exhaust finishers... which are not exhaust finishers at all. They're complete fakes, the real exit pipes being downturned behind the rear bumper. This is taking the egregious effort of the SQ5's false exhaust outlets to a whole new level, but we're not prepared to mark the S6 Avant down for this nonsense alone.
Inside, it's an upmarket Audi. Which means the interior is blessed with three gorgeous digital screens, the fit and finish of the materials used is second-to-none at this sort of price point and there's a load of space on board for four adults to get comfortable, as the centre-rear seat's foot room is impacted by the transmission tunnel for the quattro drivetrain. Sure, the S6's cabin may be a bit sombre in terms of design flair, but when everything is so ergonomically spot-on you really couldn't give two hoots about that. Plainly, outside and in, this is an Audi that oozes desirability from every pore.
For an S-model Audi, the way the S6 Avant drives is nothing short of perfect. You're not talking about an RS model here; one that must try and convince you it can destroy the Spa Francorchamps racetrack as well as it can whisk you to the local spa for a relaxing afternoon of treatment. Instead, it's an S Audi: that means it must be fast, secure, understated and in no way demented nor uncouth. It might sound a touch condescending of us, but the S range of cars has a lower dynamic bar to clear than the RS family.
Thus, setting your expectations of the S6 accordingly (you have to kind of forget that the old S6 had a biturbo V8 petrol engine and, going back one more generation, that it packed a Lamborghini-derived V10, no less) then the new car meets and exceeds all its pre-game targets. For a start, while previous S6s might have had more power, none of them possessed a socking great 700Nm of torque. This makes the TDI quite brutally quick once it's rolling, while step-off acceleration is mighty thanks to the traction advantages of quattro. The eight-speed auto is a fine companion for the thumping great 3.0-litre V6 diesel and it even sounds wonderful; artificially augmented, of course, as everything seems to be these days, but the rumbling gargle the S6 makes in Dynamic mode is hugely appealing and allows you to forget you're in a turbodiesel completely.
Handling is as-per many a quattro Audi, which means you can bung this two-tonne wagon into corners (in the dry) at speeds that verge on the insane, and it will grip and get around the bend with little drama; aiding circumstances here is the optional Dynamic All-Wheel Steering, one of the best four-wheel-steer set-ups on the market. Where the S6 is particularly more involving than its predecessors is the steering - it might not have the finest level of detail in the world, but the weighting and the smooth progression it offers just off-centre (no 'dead' patch here) is most refreshing. Out-and-out great steering, it is not, yet by the standards of fast Audis of the past, it's a peach of a set-up and one that allows you to exploit the vehicle's talented chassis and drivetrain to the max.
The damping is the best part of the process, though. The S6 comes on adaptive dampers and conventional springs as standard, with air suspension an option. We tried the former and it was magnificent. Body control, for such a heavy car, is exceptional and yet, when you throttle the S6 back, the ride quality is superb. It might well be that the Audi is less impressive on our own cratered tarmac, but somehow, we doubt it. Indeed, mechanical refinement is excellent across the board on the S6 Avant, which you'd probably expect... nay, demand of it.
The Audi's skill this time around, of course, is that it can offer all of the above (plus some incredibly confidence-inspiring brakes that stood up to the rigours of Autobahn-speed deceleration time and time again) with fuel economy that's no longer diabolical. Sure, if you thrash the S6 and enjoy the TDI's charms, you're going to guzzle through diesel in the order of 13 or 14 litres/100km - but, driven a bit more sensibly, we have little doubt it will return 8-10 litres/100km, which is much more like it.
So have we got any criticisms of the S6 Avant? Well, there is one. The automatic gearbox, for all its smoothness of shift and ability to handle mega-torque, does that Volkswagen Group thing of hesitating when you plant the throttle to the floor. This is only a major problem if you're going to take the minutest of gaps in traffic on a regular basis or you enjoy hurtling into questionable overtakes that really aren't on, as it's easy to drive around this niggling trait with a bit of forethought. Nevertheless, given this TDI engine has a 48-volt mild hybrid system and an electrically powered compressor (EPC - just like the SQ7) in order to negate any hesitance on the part of the turbocharger, it's a shame the gearbox re-introduces this bit of 'pseudo-lag' back into proceedings.
What you get for your Money:
The Audi S6 Avant is a near-€100,000 car in Ireland, when a base A6 saloon is a little more than €50,000. That means it's not exactly a bargain, but a comprehensive kit list - including the adaptive dampers and 20-inch wheels, as well as Audi Drive Select, S Super Sport front seats, Valcon leather upholstery, Parking System Plus, Matrix LED headlights and MMI Navigation High, among more - and the TDI's ability to offer top-end performance with rather more manageable running costs mean it's a vehicle that emphatically feels worth the asking price.
Flipping fast, plenty of fun and reasonably frugal, the Audi S6 Avant is the consummate all-rounder: it has that weird and oh-so-hard to get right blend of attributes that make it master of all trades, not just jack of them. It's pricey and there's the slightly hesitant gearbox issue to work around if you're an aggressive driver and those fake exhausts are an annoyance, but in every other respect the S6 Avant is so good that it will have you wondering whether you'd really need an RS 6 instead. Or, indeed, any number of inferior SUVs/crossovers. This is a pacey family chariot done perfectly.