New Mercedes-AMG C63: the big road test

The old chap standing by the side of the road in a small village somewhere about an hour south of Lisbon has patently heard me coming. He's paused in the dusty, cobbled margin, peering at the dark blue Mercedes-AMG C63 S as if slightly disappointed that the thunderous noise he must have heard from a few miles away has resolved into a fairly innocuous-looking blue saloon.

But, heading towards the village, I have knocked the C-Class into Comfort mode, popped the exhaust into a more socially acceptable configuration and slowed. He raises an eyebrow - difficult when your skin is the texture and colour of saddle leather - smiles and points both thumbs skywards in the universal sign of approval. With his hair slicked back and tiny ears, I can't help feeling that I've just been given the thumbs-up by a giant, man-shaped Portuguese otter.

I'll admit, the new Mercedes-AMG C63 has already proved itself a thumbs-up kind of car. I've only been driving it for about three hours, but already I've pottered luxuriously down a motorway, dealing with overtakes with the kind of languid nonchalance that comes from over 500lb ft, a V8 and turbos. I've played with every setting, understood them all, and deposited myself at the end of a very wriggly, unevenly surfaced road with a grin so broad it's medically unlikely, and a set of optional carbon-ceramic brakes that are quite noticeably on fire.

This sounds like a bad thing - but when you realise just how tortuous the road, and just how fast the C63 can be, it's surprising that the brakes are only on fire and not simply puddles of shiny slag wrapped around the tyres. This thing is immense... and yet it looks like a pretty unlikely hero car.

Pictures: Lee Brimble

This feature originally appeared in the March 2015 issue of Top Gear magazine. 

Outside, it's actually quite subtle. Or as subtle as 500+bhp is likely to get. The usual AMG ‘power domes' bulge up through the bonnet like semi-steroidal extra musculature, and the stance is subtly different to a cooking C.

Obviously the front wings are flared to cope with a wider track (more on that in a bit) and there are the planet-swallowing front airdams to chill various intercoolers. The wide pair of bumper sidepods actually help balance the front end of the C, making it look nicely angry rather than full-on brutal. Little sill extensions join front to back, and there's a vestigial spoiler on the boot lip, as well as a pair of less inconspicuous squared-off exhausts either side of the rear valance.

But if it didn't carry ‘V8 Biturbo' badges, you might even miss it. But this is a car that ascribes to the speak softly/big stick theory of super-saloons. And the stick it carries has a nail through the end.

The engine itself is the new 4.0-litre V8 with a pair of turbos nestled like hibernating snails in the vee of the cylinders, and it's very closely related to the unit in the Merc-AMG GT sports car - in fact, they're only one number designation apart, codenamed ‘M177' and ‘M178' respectively, the C's engine being a wet-sumped version of the GT's more racy dry-sumped motor.

The big numbers are 510bhp and 516lb ft for the S we have here (a not-exactly impotent 476bhp and 480lb ft as ‘standard'), but more important for Merc-AMG is the fact that it's a third more efficient than the old 6.2-litre naturally aspirated V8 in the previous-generation C-Class. That's impressive, and apparently provides the new C63 with the ability to do nearly 35mpg driven carefully. For a car with more than 500bhp, that's extraordinary. Although, let's face it, also extremely unlikely.

It's also, as is AMG tradition, still a hand-built motor, featuring the embossed signature of the person that assembles it - ours was built by a certain Jan Giela (it could be ‘Ciela'). And I have to say that Herr Giela did a hell of a job.

It doesn't feel like it has turbos is perhaps the best compliment I can give it. That, and the fact that delivery is linear, elastic and crushing. It also sounds really rather wonderful: a gentle burble in Comfort, a roaring, spitting, banging and backfiring leonine pitfight in Race mode.

Yes, you can hear the turbos spooling up if you really listen carefully, but there's no sense of ‘boost', just torque - it really does feel just like a much larger capacity - which means that modulating throttle through a corner is a joy rather than a gamble. Of course, you can adjust the ferocity of delivery via the various modes, but generally, it just feels immense, everywhere.

And I guarantee that - apart from arriving home late at night - you'll leave the exhaust button in ‘open'.

The front suspension consists of four links and a wider track than before; the rear, a similarly slightly fatter-tracked traditional multi-link with independent mounts. Both ends are tied together by AMG's electronically controlled ride-control system, offering three strata of firmness: Comfort, Sport and Sport+, accessed from a series of buttons around the touchpad controller.

The S also gets a further option in the COMAND system called Race, that allows the driver to play with the various functions (engine response, damping, gearbox and exhaust) to optimise their own preferred set-up, linked to an S-specific electronic rear differential.

The transmission is a bit of a mouthful, called as it is in official Merc parlance an "AMG SpeedShift MCT-7" semi-auto, but it's been uprated to punt out what the company refers to as "significantly quicker shift times". It's technically an auto without a torque-converter, instead using a wet start-up clutch and then the gearing of the auto, but all I know is that it's quick enough to react to the paddles, but smooth enough dawdling in traffic.

The standard car gets a straight mechanical locking rear diff, and the S gets that electronic version which apparently reacts a little quicker and adds a level of finesse when matched to the bespoke modes in the Race function. Also, there's the usual suite of traction and stability controls to keep everything pointing in vaguely the desired direction.

Fun stuff includes a Race Start function (left-foot brake in either Sport+ or Race, pull both paddles, acknowledge by pulling the right-hand paddle, floor the accelerator and lift brake), which gives picture-perfect starts every time, amusingly keeping the tyres squealing on the very verge of everything they have in terms of grip all the way through second gear. Merc-AMG reckons 4.0 seconds dead to 62, and I think that's eminently feasible. In the dry.

Switch it all off, and the engine simply dominates. Feather the brake on launch and the C63 will do quite spectacular rolling burnouts. Yes, I know it's pointless, but it's good to see a modern car with such an oblique sense of humour.

The slightly confusing thing comes when you hit proper corners at speed. Initially, the ride can seem a little prone to jiggling over some of these badly surfaced Portuguese roads (with a couple of odd squeaks from interior trim on this early car), but start to go a bit faster in some of the more sporting modes, and the car feels like it sheds about 200kg.

Turn-in is sharp rather than darty, and the C doesn't seem to lean - just like the AMG GT, the C63 features active engine mounts that slacken to reduce vibration and NVH from the engine/gearbox combo during cruising, and tighten during more committed driving to improve response. It basically reduces disturbing inertia in the oily bits during cornering, leading to a more instant-feeling response from the steering wheel. It works, meaning you can pick a line and stick with it, rather than constantly adjusting.

The Portuguese have a habit of cobbling the apexes of their country lanes, and you can get a satisfying "braap" of skimming contact every time - which means you're inevitably accurate. There's also great feedback about grip levels - this isn't a car that you have to second-guess, which leads to confidence.

Similar confidence comes from the brakes, which are mighty, regular, fade-free and dinner-plate large: 390mm discs at the front and barely smaller 360mm discs on the rear. I would, however, option the ceramics if you like going fast or intend any sort of track work - our own BBQ experience showing that they're probably a wise option.

More than that, though, this car is just good fun. It doesn't do anything odd, and you never have to drive around a foible - it's just a nicely set-up saloon with a gorgeous engine. Proper stuff. I suspect on a track it might feel a little heavy, but, as a road car, I was struggling to find fault.

Inside, the steering wheel isn't flat-bottomed so much as appears weirdly oblong (though that might be my eyes), but the seats are deep, contoured and fantastic, and there's a strangely wonderful feeling of density that encourages happy feelings.

As ever with a super-saloon, there's no hasty or gimmicky remodelling of the interior - it's architecturally similar to a run-of-the-mill C-Class - but with the seats, wheel and various splashes of carbon, it feels more special than any option-pack agglomeration ever can.

Top options include lovely Burmester surround-sound audio (though I didn't use it much, just kept putting the exhaust in Sport), an even louder variable AMG sports exhaust, head-up display and intelligent LED headlights. There's also an Edition 1 variant that costs £73,500 which gets bespoke finishes and extra bobbins, but basically it's a gussied-up S to celebrate the launch of the car.

There's also another little kicker in the shape of the C63 Estate from £60,995. Just about the perfect size, pretty much all of the performance (same top speed, only 0.1 seconds added to either model's 0-62mph time, under 1mpg less efficient) and even less likely to attract attention, it's a properly attractive semi-sleeper. But we've always been suckers for a fast wagon here at TopGear.

Generally, though, I came away with one thought: I'd rather have a C63 than a BMW M3. That's big news for me. But when you have a car that's subtle-but-good-looking, an absolute joy to drive quickly without scaring you witless, capable of carrying the family and putting the wind up a serious sports car, you know you've got a winner.

Bring on the head-to-head comparisons. I don't think Mercedes-AMG has much to worry about.