Mercedes CLK63

AMG aims for increased driver appeal, with the 500bhp CLK63 Black Series

Evo rating
from £100,000
  • Wonderfully balanced chassis, looks, build quality
  • Not quite sharp enough to rival GT3

AMG. What images do those three simple letters conjure up for you? Let me take a guess… A sober saloon bonfiring its rear tyres? An S-class sitting serenely at its 155mph limiter, only electronics preventing it from rushing headlong towards the double-ton? A huge V8 squeezed tightly into the engine bay of a C-class? In other words, an image of unlikely and monumental power. In fact, if you didn’t know any better you could almost surmise that AMG was German for BHP.

Now, I’ll admit I’m a bit of a horsepower junkie; I love the way it wraps you up and takes you into the distance in giant strides. It’s intoxicating, empowering, exciting, but obviously it’s not enough on its own to make a truly great drivers’ car. And too often it has been the centre of the AMG experience at the expense of agility, balance and response, not to mention such wishy-washy notions as passion and character. Traditionally AMG is a company that demands respect, but somehow its over-endowed range has never quite captured the imagination like the products of BMW’s M Division.

With this in mind, you might expect a car specifically produced to coincide with AMG’s 40th anniversary to be a limited-edition 700bhp S-class, or an E-class estate capable of 200mph. Awesome, awe-inspiring even, but slightly irrelevant. A monumentally fast car, but one designed for people who will only tap into its potential when the road ahead is very long and arrow-straight. Well, think again. This, the CLK63 AMG Black Series, is part of a new breed of AMG…

We’ve already tried the SLK55 AMG Black Series (evo 095), and that encounter was enough to convince us that the Black Series cars are designed for people like you and me. AMG takes a ‘standard’ car, strips weight out where possible, adds a few horses, strengthens the chassis, redesigns the suspension, steering components and even bodywork, and slavishly laps the Nürburgring until the car is honed into a very serious track tool and a refreshingly uncompromised road-racer. When I ask AMG’s head of development, Tobias Moers, what car the CLK Black is pitched at, his answer is music to my ears: ‘GT3,’ he utters with a shrug.

Maybe that should be GT3 RS. The CLK63 AMG Black will cost around £100,000 when it goes on sale in June. Again, the engineers are deadpan when the price is revealed, but when you see everything that goes into making the Black, you can start to understand why it’s such an expensive tool.

Let’s start with the basics. The 6.2-litre V8 (still fed through Mercedes’ seven-speed auto gearbox) benefits from a more generous intake system allied to a less restrictive (and louder) exhaust system. With the ECU suitably tweaked to take advantage of these modifications, power takes a jump to 500bhp – 26bhp up on the normal CLK63 AMG. This helps to lower the 0-62mph time to 4.3sec (a drop of 0.3sec), and the Black will keep on charging to 186mph (300kph) before its more lenient limiter stops play.

Cooling has been improved with larger air-intakes in the restyled front bumper feeding a bigger radiator. AMG has also fitted an additional transmission oil cooler and an engine oil cooler (one in each of the front wheelarches), plus a more efficient power-steering cooler. Move further back and you’ll find a multi-plate limited-slip diff (30 per cent locking under acceleration, 10 per cent on the overrun), again with its own oil cooler.

All of this hardware is shrouded in bespoke bodywork, with minute attention to aerodynamic detail. Check out the rear diffuser (carbonfibre, naturally) sprouting from the bulging rear apron. And the carbon boot spoiler and neat air outlets in the swollen plastic front wings. It’s a feast of detailing, with every vent, slash and splitter wonderfully fit for purpose.

Open the bonnet and you’ll see a big strut-brace linking the suspension turrets, and there’s another one in the boot, too. You can’t see the extra triangulation in the chassis, but it’s there.

It’s clear from the reinforced structure and the additional cooling that AMG expects the Black to be used extensively on track. And to make sure it performs as spectacularly as its new, more muscular physique suggests, the suspension too is almost entirely new. Both front and rear axles gain bespoke spring links, wheel carriers and thrust-, camber- and torque-arms; the track is increased by 75mm at the front and 66mm at the rear, and ride height and compression and rebound damping are fully adjustable. Just like on a GT3. And as a final touch, AMG rips out the rear seats. You get the impression that, if the engineers could have their way, they’d remove the front passenger seat, too. This is one very serious car.

Excited yet? I am. Despite a fug of jetlag muddying my senses and the stifling heat of the Californian sun, there’s a swarm of butterflies filling my stomach. And when our bright red Black rolls into view I’m rendered momentarily speechless. It looks incredible: pumped-up and pared-down all at the same time. It’s a big, imposing car, but you sense there’s not a micron of fat left on its bones. The noise, too, is remarkable; it has that big, enveloping V8 rumble you’d expect of its 6208cc displacement, but even at idle there’s a lean, athletic edge.

It takes a while, but at last I can speak again, although all I can summon is a considered ‘Phwoarrr…’ Photographer Andy Morgan nods in agreement. Then we jump in and head out into the LA traffic. Now, this isn’t my idea of fun, but it does give us plenty of time to appreciate the sculpted, supportive seats (fixed-back buckets are also available if you want the full-on racer experience), the carbon/Alcantara touches that sweep around the cabin, and the delicious, elliptical steering wheel. It’s also a great way for AMG to illustrate the advantages of that 7G-Tronic automatic gearshift (there are paddles, of course, which lock out any electronic intervention if you select ‘M’, for manual, down by the stubby gearlever) and the big V8’s wonderful tractability.

To be honest, I’d rather have taken this as read (the Black is the seventh model to feature this drivetrain), but if LA’s clogged road network reveals little, it’s amazing what it can’t hide. The Black feels taut, hard even; the steering is heavy and quick. There’s an immediacy and intensity that I hadn’t expected. Even at walking pace it exudes real aggression and, more importantly, it engages you. The spec sheet suggested as much, but it still seems strange to be in a Mercedes that feels so hyper-alert.

Fortunately, unlike much of the US, there are plenty of challenging roads within close proximity of LA, and AMG has thoughtfully laid-on a racetrack, too. The latter, Willow Springs, is a bit of a dust bowl, but it has miles of twists and loops that can be attacked in various formats, and it should at least begin to reveal whether AMG’s claims that the Black is a truly hardcore drivers’ car are accurate. However, it’s on the tortuous, climbing and spectacular road route that we find most of the answers we’re looking for…

The road-book reads ‘Turn left onto Spunky Canyon Road’. An unfortunate name, but it is a very exciting ribbon of smooth asphalt, and if you happened to live in a country damned with the grid system and suddenly found yourself on this route, I can see why you might get a little carried away.

Anyway, Spunky Canyon Road is quite narrow (about the width of your average British B-road), and climbs rapidly, via tight hairpins and blind, oddly cambered third-gear corners before falling back down into the valley with an incredible array of endless tightening-radii corners and sharp drop-offs that an American would compare to the corkscrew at Laguna Seca. We’re on the fringes of the desert now, and the surface is dusted with loose sand. It’s quite a test.

The 6.2-litre V8 makes light work of the heat and the gradient, launching the Black at the canyon with a relentlessness that only AMG products seem to summon. The soundtrack is tight, hard, highly tuned V8. Gearshifts snap through with a noticeable thunk in ‘M’, but the lag in torque to the rear wheels is minimal. They cope admirably, thanks in part, no doubt, to the huge 285/30 R19 Pirelli P Zero Corsas (yes, the same as you’ll find on a Ferrari 360CS or the previous-generation GT3 RS). They’re soft and sticky even in cool conditions, though with the temperature climbing to 95 degrees they’re Blu-Takking the Black to the surface.

But it’s not the grip or the grunt that sets the Black apart from its stablemates. No, it’s the speed with which the front tyres respond to your inputs, and the way the chassis seems to be hardwired-in to your right foot. There’s little body-roll despite a hefty 1760kg kerbweight, and the front end is so well tied-down and so alert that you rarely even think about understeer. It’s quite remarkable considering there’s a huge V8 up front.

Instead you sense it’s the rear of the car that you need to manage. You turn in, hard, and the rear gently but immediately takes on a few degrees of slide. Stay on a constant throttle and the attitude fixes, the car just on the verge of oversteer but requiring no correction at all. As the corner opens out and you gradually open the throttle the car stays hooked-up, but still it’s teetering – beautifully balanced and working all of its tyres equally. There are tiny shifts in grip and load going on underneath you, and because you’re located so well in the seat you can react instinctively to correct them before they become troublesome. And this is with ESP engaged.

Still, it’s a good job that the CLK’s chassis relates information so readily to your backside, because the steering is severely lacking in this respect. It’s quick and meaty, but there’s an odd viscosity to the assistance that takes some getting used to. And even when fully loaded up, front tyres on the cusp of losing grip, there’s little to signal that you’re running out of grip.

It’s a severe gripe in a car that targets the GT3, a car blessed with incredibly detailed steering feel. But, thankfully, such is the CLK’s balance that you can drive through this slightly unnerving characteristic, and turning off the ESP (‘off’ now finally means just that in AMG products) feels like the natural thing to do rather than a leap into the unknown.

It’s worth the risk. That mild oversteer stance is just so easy to induce, and now you have the option to add some angle should you desire thanks to the accurate throttle and deep well of torque. In fact, for a 500bhp, £100,000 car with huge, soft-compound rubber and stiff, track-optimised suspension, the Black is surprisingly forgiving and playful to slide. And with 7000rpm to utilise, you never seem to run out of options.

So the chassis feels wonderfully balanced (although it remains to be seen if it copes with really lumpy tarmac – the odd sharp ridge we did find seemed to knock the Black off line), but the steering isn’t nearly as tactile as it should be.

The brakes? Well, they’re huge 360mm items at the front, 330mm at the rear, so it’s no surprise that they feel very strong, easily resisting fade even on the downhill sections. But, again, it’s in the details that the CLK slightly disappoints. The pedal feels imprecise and mushy, and this is exacerbated by the ‘Speedshift’ gearbox, which always seems to lag a few milliseconds behind your gearshift inputs. It undermines the integrity of the rest of the package, and where you should be absorbed and working in unison with the car, it sometimes feels like you’re having to pull it along behind you. It’s a shame, a frustrating filter between you and the obviously gifted chassis.

The same criticisms remain true on the track. You brake deep into a corner and go for a downshift and it arrives just a fraction too late, causing you to run wide. You want to short-shift out of a corner to avoid wheelspin and there’s a moment of fluffiness where the gearbox is wrongfooted – suddenly all that torque counts for nothing. And despite all the rubber at each corner, the weight of the CLK eventually tells; it simply doesn’t generate the grip of something like a Porsche GT3 or Lamborghini Gallardo.

That sounds very damning, but I don’t mean it to be. The CLK63 AMG Black Series is a wonderful car, and I’m delighted that AMG is beginning to cater for real enthusiasts. I’m delighted, too, that it has created a car with such fine balance, such impressive quality and such incredible attention to detail. But it has obviously been working to a budget, one that didn’t allow it to reprogram the gearshift or work on brake feel – the little things that could really elevate this car to GT3-rivalling status. The 63 Black is a tantalising taste of the depth of talent and enthusiasm at AMG. If only it were able to employ them to the full.


EngineV8, 32v, 6208cc
Max power500bhp @ 6800rpm
Max torque465lb ft @ 5250rpm
0-604.3sec (claimed)
Top speed186mph (limited)
On saleJune 2007