The new Audi RS4 Avant is blisteringly quick, but does it have what it takes to beat Mercedes-AMG’s bad boy, the C63 S Estate?…

The contenders

Audi RS4 Avant V6 TFSI quattro

List price £62,175

Target Price £61,625

New RS4 Avant marks a return to twin-turbo V6 power and its performance is explosive.

Mercedes-AMG C63 S Estate 4.0 V8 Biturbo

List price £70,325

Target Price £65,707

Twin-turbo V8 and rear-wheel drive chassis: the perfect fast estate car combination?

In ideal conditions, a cheetah can accelerate from 0-60mph in around four seconds, a springbok can leap through the air at a velocity approaching the national speed limit and a peregrine falcon can generate 0.6g in a full dive. But despite what the Discovery Channel tells you, none of them holds the outright acceleration record for an animal.

No, that particular record belongs to a mate’s dog Sprocket, a 13-year-old Staffordshire bull terrier, who recently experienced launch control in the new Audi RS4 Avant, Audi’s four-wheel-drive performance estate car.

In fact, it takes just a quick look at the RS4’s spec sheet to realise why a dog harness is offered as an option. Powered by a new 444bhp twin-turbo 2.9-litre V6 in place of the previous model’s 4.2-litre V8, the RS4 covers the 0-62mph sprint in a claimed 4.1sec and has a top speed (optionally derestricted) of 174mph, surely making it the quickest way to get your four-legged friend to the groomers.

Or is it? You see, Mercedes-AMG already fields a super-fast Mercedes C-Class Estate in the same class, and it doesn’t look any less compelling now that the RS4 is back on the scene. With more power from its twin-turbo 4.0-litre V8, the C63 S Estate is capable of being a serious thorn in the RS4’s haunched side.

Driving

Performance, ride, handling, refinement

Whereas performance saloons can get by on good looks and sharp driving dynamics, their estate brethren have to fulfill a broader remit. Not only do buyers crave dynamic exuberance and neck-snapping performance, but such ability also needs to be wrapped up in a practical and refined package. And on this front, it’s the RS4 that delivers the first blow.

Fitted with optional Dynamic Ride Control (a system that uses three-mode dampers), the RS4 exhibits the kind of low-speed compliance that is usually reserved for luxury limos or plush SUVs. Where the C63 bumps and thumps its way around urban routes, the RS4 smoothes out the worst of battered bitumen. Not since the McLaren 720S has a performance car impressed us so much with its comfort.

But, of course, the magic of the McLaren is that it offers up firmer responses and excellent body control when the roads become more challenging. And that’s where the RS4 begins to struggle. Left in Comfort mode, the RS4 feels like a fishing trawler caught in a storm, wallowing and pitching under acceleration and braking. Both Auto and Dynamic modes improve the RS4’s body control, but it never feels as well tied down as the conventionally suspended C63.

In fact, it is the rear-wheel drive C63 – a machine that has developed something of a bad boy reputation over the years – that gives you the most confidence on demanding roads. The RS4, with its vague dynamic steering and unpredictable handling, tends to leave you guessing on the way into corners, whereas the C63 positively bristles with feedback, with its feelsome steering and accelerator allowing you to exploit its potential at every opportunity.

The RS4’s four-wheel drive traction doesn’t net it much of an advantage in a straight line, either. Yes, from 0-60mph the RS4 fires out of the gate like a rocket-propelled greyhound (3.8sec versus 4.3sec), but at higher speeds the C63 claws back the advantage. Better yet, this muscular performance is accompanied by a delicious V8 growl and angry rasps from the tailpipes during upshifts.

The RS4 is altogether more subdued, generating less engine, wind and road noise than the C63 – so it’s less tiring on long journeys. However, for an Audi Sport product – a car that should excite and move in equal measure – it’s a little bit disappointing.