Mercedes-AMG’s C63 Estate delivers huge performance in an understated package, but can it outclass Audi’s RS4 Avant?

The previous-generation Mercedes C63 AMG, with that rather wonderful normally aspirated 6.2-litre V8, was a sales phenomenon in AMG terms. In a seven-year lifespan, some 40,000 units were sold, making it Mercedes’ most successful ever performance car by a clear margin. The saloon derivative was the most popular version, closely followed by the coupe. The estate model, however, accounted for only ten per cent of W204 C63 sales, which by any measure makes it a pretty niche product. 

This latest version, based on the fourth-generation C-class and powered by a 4-litre twin-turbo V8 rather than the old 6.2, will also find far fewer homes than the saloon and coupe derivatives, but somehow its intrinsic appeal far outstrips its share of the sales. The less popular relation they may be, but fast estate cars are cool. Perhaps that’s a direct result of their rarity; or maybe the whiff of utilitarianism punctures any suggestion that the driver is overly concerned with image. If you want to turn heads, after all, you wouldn’t think twice about the estate model. 

So the £60,000 high-performance estate car is a pretty compelling machine, but that lack of volume means examples of the breed are few and far between. In fact, if you’re in the market right now, these are your only options. The Mercedes-AMG C63 Estate arrived on our shores in the summer, just as the Audi RS4 Avant was being discontinued. Audi dealers are not at all short of delivery-mileage examples at full list price, though, so the C63 doesn’t yet have the sector to itself.

For the punch it packs divided by the number of heads it turns on a given high street, this particular flat-white C63, with its 18-inch wheels, could be in a league of one. No other car on sale today disguises its accelerative potential as cunningly as this, which begs two questions. One, is the estate version the pick of the new C63 range, and two, is it a better car than the RS4 Avant?

That twin-turbo V8 is very closely related to the engine that powers the AMG GT coupe, which we know to be one of the finest modern turbocharged performance engines anywhere. It’s good for 469bhp at 5500rpm and 479lb ft of torque all the way from 1750 to 4500rpm. It drives the rear wheels via a seven-speed automatic transmission – not the twin-clutch ’box that the GT uses – with a mechanical locking differential employed to prevent that huge slug of torque from conflagrating the inside tyre at every corner exit. 

The C63 Estate weighs 1710kg, which is 70kg more than the four-door model. The acceleration figures are staggering: 0-62mph in 4.2 seconds is quite silly for such a weighty, two-wheel-drive car. At £61,260 this model undercuts the S version by £6750. That premium buys an extra 34bhp, an electronically controlled locking differential – which responds faster than the purely mechanical item – and a slightly sportier chassis tune, as well as bigger wheels and a much more overtly sporting exterior. 

If you’ll allow me to disappear up a side track for a moment, there are two schools of thought on the matter of S versus non-S: some love the idea of the cheaper model’s car park camouflage styling while others find it terribly boring to look at, particularly for a machine with such stupendous levels of performance. Whichever camp you fall into, you’ll surely agree that packing a punch as big as this and making such little fuss about it is quite cool. 

Anyway, of these two cars, the B8 RS4 is certainly more extrovert in design terms. In fact I reckon it’ll be remembered as a high watermark in performance estate car design, not least because it so elegantly incorporates flared box arches into an already handsome shape. 

Having arrived in 2012, this generation of RS4 just about predated the sudden and across-the-board adoption of downsizing and turbocharging, which means it uses what could be the last of the normally aspirated, 8500rpm V8s. It’s amazing how quickly the notion of a high-revving ‘vee’ engine has become so romantic, such a cause for celebration. On the flip side, though, it does mean the C63 absolutely murders the RS4 for torque output: with 317lb ft at 4000rpm the Audi concedes 162lb ft to the Mercedes, which offers maximum twist 2250rpm sooner. The All Blacks’ rugby forwards would have a tougher time scrummaging against the Eastbourne branch of the Womens’ Institute. At least with 444bhp the Audi only gives up 25bhp to the Mercedes. 

The four-wheel-drive RS4 is half a second slower to 62mph than the rear-driven C63. It does, however, use a twin-clutch transmission, and that, as we’ll see, makes quite a difference on the road. The RS4’s Sport Differential also promises to enliven the car’s driving dynamics by actively apportioning torque between the rear wheels.

The Audi’s cabin is so familiar now that it’s easy to forget just what a fine interior it really is. The architecture may be a touch functional, but the quality of the materials and fit and finish are very impressive and the Multi Media Interface system is intuitive to operate. 

Time has been kind to this car. Much like the RS5 that impressed and surprised us when we put it up against the BMW M4 and Lexus RC F in issue 206, this RS4 is a better car now than it’s ever been. It’s quite clear that during its time in production Audi has knocked back the spring rates a touch, because whereas the early cars rode almost unforgivably harshly, this example is actually quite fluid and relaxed. It’s only over bigger potholes and ridges that it begins to feel crashy.

The engine is also more enjoyable now than ever. In the company of the old Mercedes 6.2-litre V8, this 4.2 did feel a little limp, but today it really is an exciting and soulful engine with a dramatic crescendo. It certainly doesn’t have the effortless, any-gear thrust of the latest turbocharged engines, but it still gives the RS4 a turn of speed that most sports cars should be mindful of. The gearbox, meanwhile, is quick-witted and sharp in its manual mode and refined around town. 

What hasn’t improved over the years is the car’s steering system. In much the same way that ancient human remains can be carbon-dated, it’s actually possible to accurately predict an Audi model year by the way it steers. Unfortunately, this RS4 is from the ‘vague and rubbery’ age rather than the more recent ‘crisp and direct’ era. 

In dynamic terms the RS4 majors on outright grip and taut control, which means it’ll carry tremendous speed down a road. It’ll do so in all weathers, too, but what the RS4 never really does is entertain its driver. There’s no real adjustability in the chassis, no way of tucking the nose in mid-corner to take a tighter line and no sense of the chassis getting up onto its toes as you approach the limit of grip. It’s just completely locked down, until it starts understeering. That Sport Differential occasionally gives an impression of the car being driven from the rear, but never to the point – on the road at least – where you find yourself instinctively opening up the steering as the car drifts gently away from a corner. That sort of two-way engagement is well beyond this car’s remit. 

In design terms the Mercedes’ cabin is evidently a lot newer, but for outright quality and fit and finish it doesn’t teach the Audi a great deal, if anything. The driver’s seat feels rather high-set, too, which makes you feel as though you’re perched on top of the car. The last of the day-to-day frustrations pertains to the gearbox, which can be irritatingly dim-witted when manoeuvring at low speed. 

Once up to speed, the gearbox is very smooth in automatic mode, but it never gives the same immediacy or control when you’re pressing on in manual mode as the RS4’s S-tronic. It’s only in back-to-back comparisons that the C63 really loses out here, though, because in isolation its shift speeds are rapid enough. 

‘Rapid enough’ is not the phrase you’d choose to describe the C63’s straight-line performance. It really is thunderously quick. Even when you’re familiar with both this ‘entry-level’ model and the more powerful S version, you don’t ever crave more raw performance, while throttle response throughout the rev-range is very good. The exhaust note is suitably potent and the engine’s top end is rampant, too, which means you’ll find yourself holding on tightly as the rev-counter needle swings around to 6000rpm. 

The C63 steers more intuitively and crisply than the RS4 – it has a less artificially manic rate of response at the front axle, too – but when accelerating hard the car’s weight shifts rearwards so forcefully that the front end becomes very light, at which point the steering can feel as though it’s become completely disconnected from the wheels. 

It’s a curious sensation – not to mention disconcerting on a very narrow road – and it’s likely to do with the way the car manages body movements when left in its default drive mode. By rotating the little wheel on the transmission tunnel you can switch the car through its AMG Drive Select modes, which adjusts its drivetrain and chassis parameters. Left alone, the car feels quite under-supported at each corner, so body movements in response to cornering or accelerative and decelerative forces are very pronounced. In fact, in the default mode the chassis feels about as sporty as the exterior looks! 

The trade-off is a very fluid ride quality at higher speeds – although at low speeds the ride does feel very firm – but, naturally, when you switch to a more focused setting the car responds brilliantly. It now offers enough support to control body movements and allows you to make the most of the tidal-wave performance. What is lacking, however, is pliancy over bumps, which means you’re forced to leave the mode wheel well alone on the very bumpiest roads. 

On smooth roads, though, the C63 is terrifically good fun and the mechanical differential distributes drive so cleanly, and throttle response is so crisp, that you can provoke the rear axle at will. 

Therein lies the innate appeal of a fast estate car. They’re untaxing in daily use, they’ll swallow a family’s holiday kit and they can be entertaining when it’s just you, the car and a good road. It’s the latter point that makes the Mercedes the pick of these two cars. And unless you really do want everybody to know just how powerful and expensive your C63 is, this entry-level AMG estate is the pick of the range.

‘The RS4 could be the last of the normally aspirated 8,500rpm V8s’


V8, 3982cc, twin-turbo
Power 469bhp @ 5500rpm
Torque 479lb ft @ 1750-4500rpm
Transmission Seven-speed MCT, rear-wheel drive, limited-slip differential
Front  suspension  Four-link, coil springs,
adaptive dampers, anti-roll bar
Rear  suspension  Multi-link, coil springs,
adaptive dampers, anti-roll bar
Brakes Ventilated 360mm discs
front and rear, ABS, EBD
Wheels 8.5 x 18in front, 9.5 x18in rear
Tyres 245/40 ZR18 front, 265/40 ZR18 rear
Weight 1710kg
Power-to-weight 279bhp/ton
0-62mph 4.2sec (claimed)
Top speed 155mph (limited)
Basic price £61,260
evo rating: 


V8, 4163cc
Power 444bhp @ 8250rpm
Torque 317lb ft @ 4000-6000rpm
Transmission Seven-speed DCT,
four-wheel drive, rear limited-slip differential
Front suspension Five-link, coil springs,
adaptive dampers, anti-roll bar
Rear suspension Trapezoidal link, coil springs, adaptive dampers, anti-roll bar

Brakes Ventilated discs, 365mm front,
324mm rear, ABS, EBD
Wheels 9 x 19in front and rear
Tyres 265/35 R19 front and rear
Weight 1795kg
Power-to-weight 251bhp/ton
0-62mph 4.7sec (claimed)
Top speed 155mph (limited)

Basic price £56,545
evo rating: 

‘The C63’s gearbox never gives the same immediacy or control when you’re pressing on in manual mode as the RS4’s S-tronic. It’s only in back-to-back comparisons that the C63 really loses out here’