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Friday 15th February 2013


German tuner comes up with a svelte, 700hp, 211mph sleeper. We'll take three.

Now, we've been accused of being a bit snobby about modified cars on occasion. Perhaps 'selective' would be a fairer way of putting it, this particular souped-up CLS from Merc tuners Carlsson drawing collective - and unanimous - oohs and aahs from the PH team.

'Power, torque and sound’. That’s how Carlsson describes its three biggest priorities in developing its new CK63 RSR (read: ‘very fast CLS’).  Not, you’ll note, ‘sparkly wheels’, ‘glitzy decals’, or even ‘spangly bodykits’ – though there are a few very subtle changes to the CK63 RSR’s cosmetics, more of which anon.

Looks are subtle; power is not.
Looks are subtle; power is not.
No, Carlsson’s priority here – as per the company’s form – has been to create an upgraded CLS that speaks softly, but carries a big stick. Well, we say ‘speaks softly’ – in actual fact, it features a full stainless steel exhaust system that includes a driver-operated butterfly, so should you choose, it can be exceptionally – and wonderfully – vocal.

The main priority, though has been more power. Lots more power. Carlsson’s renowned for its founder, Rolf Hartge’s expertise in extracting vast amounts of power from production Merc engines. In this instance, he and his team have taken the CLS63 AMG’s 5.5-litre twin-turbo V8 – already no slouch – and added their own software to take it to 700hp. Peak torque has been limited to 737lbft, meanwhile, to make sure the gearbox and the rest of the drivetrain doesn’t have a small fit. Carlsson has also had to add a higher-flowing intercooler system and a selection of water and oil coolers, as well as that uprated exhaust.

Bi-turbo serves up 700hp. Seven hundred.
Bi-turbo serves up 700hp. Seven hundred.
So, that takes care of the ‘power, torque, sound’ objective. The rest of the car’s been left well alone, then. Right? Well, not quite, though what has been done has been kept suitably low-key. First up, a set of Carlsson’s own coilovers allow adjustable handling, though they’re set to a 30mm drop as standard. Meanwhile, there’s a 25mm wider front track to increase stability. Unsprung weight is aided by a set of rather smart ten-spoke alloys, behind which lurk 405mm brakes.

And of course, there are those external upgrades. Thankfully, these have been kept as unobtrusive as possible, though there’s one notable change from the lower spec CK63 RS in the form of an electronic rear spoiler that rises at 62mph. Carlsson says that this, in combination with the new rear diffuser, has been wind tunnel tested to help reduce lift at the rear. Inside, much as you’d expect, there are swathes of Alcantara, wood and carbon fibre, as well as the hides of several herds of Friesians.

Just as luxurious as you'd expect in here
Just as luxurious as you'd expect in here
Stats junkies will, naturally, be frothing at the mouth by now. Froth no more. The RSR hits 62mph in a supercar-baiting 3.9 seconds, while Carlsson claims it’ll go on to a frankly astonishing 211mph. On its way there, 125mph (or 200kph, hence the milestone) will come up in 11.6 seconds. Crikey.

The CK63 RSR will be unveiled officially at Geneva, with order-taking to commence shortly thereafter.

Author: Alex Robbins
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