Though the switch to V6 power has proved to be surprising for some, the same can't be said of the RS 4's fundamentals. Quattro all-wheel drive is a given and the fitment of an 8-speed tiptronic twin clutch auto gearbox wasn't a shocker given the need to control a lusty 600Nm of torque. The set-up certainly works well with the 450PS 2.9-litre TFSI biturbo engine, which powers this car to 62mph from rest in just 4.1, six-tenths of a second quicker than the old MK3 model's 4.2-litre V8 could manage. As before, this family estate can hit 174mph on the Nurburgring (if you specify the optional 'RS Dynamic' package) but is just as happy collecting your dry cleaning. You only truly get a sense of just how fast it is by following behind in something else.
The standard-fit RS sport suspension sets the Audi RS 4 Avant another seven millimetres lower than the standard A4 with sport suspension. An 'RS sport suspension plus' package with 'DRC' 'Dynamic Ride Control' is available as another option, as are ceramic brakes and RS-specific dynamic steering. Drivers can define their own individual personal driving experience using the standard dynamic handling system 'Audi drive select'.
Audi RS 4 models have always blended just the right amount of discretion and malevolence. They've never been head turners but let your eye linger long enough over one and there are enough clues that this isn't your garden variety load lugger, something that continues with this fourth generation model. The designers apparently took inspiration from many motorsport details of the Audi 90 quattro IMSA GTO racer. Massive air inlets with typical RS honeycomb structure and the wide, flat Singleframe grille define the front end. Compared to an ordinary Audi A4 Avant, the wheel arches are 30 millimetres wider and are given added emphasis by the quattro blisters. At the rear end, the RS-specific diffuser insert, the oval tailpipes of the RS exhaust system and the RS roof edge spoiler make for a distinctive look.
Inside the all-black interior, the RS sport seats can feature an optional honeycomb pattern, while the flat-bottomed RS leather multifunction sport steering wheel, the shift gate and the illuminated door sill trims are all adorned with the RS emblem. In the standard 'Audi virtual cockpit' digital instrument display, RS-specific graphics indicate g-forces, tyre pressures and torque. Optional styling packages ('gloss black', 'carbon with aluminium attachments' and 'carbon with black attachments') provide further scope for customisation.
It's vaguely pointless to try to assess the value proposition of the RS 4 because it effectively competes in a class of one. Yes, you can buy rapid estate cars from other manufacturers but the RS 4 has a very specific appeal, four wheel drive and commands a loyal customer base. Needless to say, Audi will have a queue for every car it imports, even at an asking price of just under £62,000. That's £15,000 more than Audi's alternative 354PS S4 Avant model.
The pearl effect exterior colour 'Nogaro blue', available optionally from Audi, recalls the first generation of the high-performance Avant from 1999. Smart 19-inch forged aluminium wheels as standard but you can also spend extra on 20-inch wheels and Matrix headlamps that dip themselves in the face of oncoming traffic. Options for the luggage compartment, which offers up to 1,510 litres of cargo space, include a rail system with load securing set and a power-operated tailgate. As you've probably figured out, it's possible to go quite large with options on this car. At least you shouldn't have to pay out for additional safety features. On top of everything we've come to expect, there's adaptive cruise control with traffic jam assist so the car almost drives itself up to 40mph. For when you are in full control, there's park assist, a cross traffic warning, plus autonomous braking.
Especially when compared to the old 4.2-litre V8 variants, this biturbo V6 RS 4 may not be as expensive to run as you may expect. Yes, the V6 diesel is cheaper still and we're not even going to bring the four cylinder models into the equation, but the RS 4 isn't much worse than some extreme hot hatches. Combined fuel consumption is 32.1mpg with CO2 of 199g/km (compare against 38.2mpg, with carbon emissions at 170g/km for the S4). Naturally, those figures will get significantly worse if you start to explore the performance on offer.
Something else to be wary of is loading the car full of options. Big petrol engines aren't great for resale in this country anyway, so don't make things worse by ticking loads of boxes on the spec sheet. While it might seem worthwhile at the time, it's unlikely the next buyer will pay extra for a lot of the equipment. The warranty is for three years or 60,000 miles. However, this can be extended for a fee.
The Audi RS 4 Avant has managed to carve out a specific and profitable niche in the performance car market and with good reason. If you have the funds not to have to worry unduly about trifling matters like fuel bills, then it's the consummate all-rounder. It's crushingly fast, effortlessly discreet, beautifully finished and genuinely practical. It'll do anything that a regular A4 Avant will and a whole lot more besides. It's as quick as a Porsche 911 yet it's good for both the school run and a kerb-hopping lap of the Nurburgring.
Drive it and you'll experience a slightly guilty thrill as if something this much fun really couldn't be legal. One day cars like this might well be legislated out of existence. In the meantime, enjoy this one while you can.