Audi had some pretty sizeable boots to fill when it launched the previous C7 generation RS6. Its predecessor, the C6, featured a 5.0-litre twin-turbocharged V10 - an engine deemed good enough for Lamborghini in its naturally-aspirated guise. The C7 had to make do with a 4.0-litre V8, which was not only two cylinders down, but modestly short on power, as well.
Fortunately, no-one could recall the on-paper deficit while driving the C7 because it turned out to be superior to the C6 in just about every way possible. For one thing, it produced more torque than the C6, and for another it was lighter. It hit 62mph in 3.9 seconds and was considered a monster right up until 2016 when Audi introduced the Performance version, which outputted 605hp and shaved an additional 0.2 seconds off the sprint time.
So when you discover that the new C8 RS6 Avant doesn't develop any more power than the outgoing car - and is still shy of the 612hp found in the Mercedes' E63 S - don't feel like you need to look away in disgust. Yes, as we expected, the new model also has to lug around the extra gubbins consistent with its 48-volt 'mild hybrid' system - but, much like its predecessor's relationship with the C6, it possesses some notable trump cards.
For a start, there's still a 4.0-litre TFSI twin-turbo V8 doing the heavy lifting. Phew. And while it has marginally fewer horses at its disposal, its 590lb ft of peak twist is 40lb ft more even the Performance could muster on overboost. It's lighter, too, despite its newfound electrification, thanks mostly to its maker's latest MLBevo platform, and both facts pressed together mean that (again) the latest RS6 is quicker than the car it replaces - 0-62 taking just 3.6 seconds. Top speed is electronically limited to a standard 155mph, although it can be raised to either 174mph or 190mph with the addition of the dynamic and dynamic plus packages respectively.
Under normal driving conditions, power is distributed 40:60 front to rear via an all-mechanical centre differential, though up to 85 per cent can be sent to the rear wheels should circumstance dictate. An optional quattro sport differential comes with both of the aforementioned dynamic packs, shifting torque between the rear wheels individually rather than just the two axles and thus improving traction, stability and response.
Automatically-adjusting air suspension also features, providing up to a 50 per cent higher spring rate, and sits 20mm lower than on a standard A6 Avant. At speeds of 75mph and above it lowers by another 10mm, while at slower paces it can raise the RS6 by up to 20mm to improve manoeuvrability. Alternatively, RS sport suspension plus with Dynamic Ride Control is available, using steel springs and three-stage adjustable dampers, connected to one another via diagonal oil lines and a central valve, helping to reduce pitch and roll.
All-wheel steering - new to the RS6 - can now be optioned in too, reducing the Avant's turning circle by up to a metre at low speed and improving high speed stability by pointing all four of the 275/35 tyres in the same direction during lane changes. Should stability not be something you're into, Audi has included two RS1 and RS2 modes, the latter of which "exists specifically to influence the Electronic Stabilization Control", which can be switched off entirely, meaning that tail-out shenanigans ought to ensue.
Aesthetically, the RS6 Avant has clearly evolved from the previous generation; if that car looked butch then this one is positively brutish. It's one of the first Audi Sport models to feature the brand's new RS design language, meaning that with the exception of the front doors, roof and tailgate, the exterior is made up entirely of RS-specific parts. The body is 40mm wider on each side, with the flared arches we've come to expect from the model sheltering 21-inch wheels (22s optional) and 420mm steel discs - 440mm if you go for the ceramic items, which also weigh 34kg less.
Beyond that the RS6 Avant adopts the front headlights from the A7 due to their "flatter, sportier expression" and RS Matrix LED laser capability, an option unique to the range-topper. Elsewhere up front, the Singleframe honeycomb grill is finished in gloss black and is flanked by a pair of enormous intakes which take their cue from the R8 supercar, while at the rear there's an RS-specific bumper with rear diffuser and the familiar oval tips of the RS exhaust system which emits a "sporty, voluminous V8 sound."
Interior-wise it's largely as you were from the A6 and S6, but sportier. An 'RS Monitor' display provides the driver with an overview of the temperature status of the drive components, the maximum g acceleration figures and information on tyre pressure and temperature. A shift light display also lets the driver know when to change up - in case that isn't apparent - and an optional head-up display "provides several RS-specific graphic displays."
There's a perforated leather flat-bottomed steering wheel with enlarged aluminium RS shift paddles, perforated RS sport seats - allowing for ventilation for the first time - and two unperforated RS design packages, red and grey, which add swathes of Alcantara to the steering wheel, gear lever and knee pads, along with contrast stitching in either of the respective colours.
A lot has changed, then, but the overall formula remains very much the same. A huge dollop of power up front, a luxurious cabin in the middle, and up to 1,680 litres of luggage space at the rear, all wrapped in a menacingly aggressive body which can be painted in one of thirteen colours, including Nardo Grey and Sebring Black. Oh, and it's crossing the pond for the very first time too. As for buyers in the UK, the new RS6 Avant will go on sale in the first quarter of 2020. By then we'll have discovered if Audi has managed to improve on its fast estate formula yet again.