Mercedes SLK 55

Here’s the proof that you can have light and dark at the same time! Mercedes’ new lightweight SLK 55 AMG Black Edition promises to be the ultimate evolution of the original metal-roofed coupé-cabriolet – and Auto Express has driven it first.

Described as a spiritual successor to the 300SL Gullwing of 1954, and coming hot on the heels of the limited-edition SLR 722 (Newsweek, Issue 919), the Black Edition is being put forward as a genuine competitor to the legendary Porsche 911 GT3.

And judging by the figures, this Merc looks more than worthy of the challenge. It’s effectively an SLK in name only – even the famous folding roof has been sacrificed for a special one-piece hard-top in an effort to extract every ounce of performance from the rear-wheel-drive chassis. Tipping the scales at only 1,495kg, and powered by a 400bhp version of AMG’s 5.5-litre V8 engine, the car now features carbon fibre panels and trim throughout.

Visual changes include wider front wheelarches and extra cooling vents cut into the bodywork, not to mention the polished multi-spoke alloys.

New race seats and special instruments help to create a driver-focused cabin. The chairs improve headroom, too, as the thin squabs mean you sit much lower than before.

But the new interior and dramatic looks are only a taste of the car’s true character. To experience the SLK 55 AMG to the full, we hit the test track. At idle, the exhausts emit an ominous rumble. However, if you press the accelerator to the carpet, they let out a roar. The 0-60mph sprint is dispatched in 4.5 seconds, and although top speed is restricted to 155mph, Mercedes estimates the car is capable of 190mph when the limiter is removed.

Yet while the urgency of the engine is impressive, the changes to the seven-speed gearbox are also worthy of note. The unit offers a choice of fully automatic and manual modes, and changes ratios quickly and smoothly.

On the test circuit, the AMG quickly proved itself a spectacular driver’s car. With a wider track, plus enhanced suspension, the revised SLK delivers vast amounts of grip. In fast sweeping corners, it’s obvious the rear-wheel-drive machine is well balanced, too. Not only does the Merc feel incredibly stable at the limit, but it also responds quickly to small inputs. Fortunately, the huge brakes are enormously powerful and more than capable of slowing the car from very high speeds. The ABS-backed set-up remains largely fade-free, even when used very hard.

But has the SLK got what it takes to overtake the 911 GT3 in the race to be the greatest sports coupé in the world? After our test drive, we can confirm that a head-to-head contest between the two is likely to be much closer than you would expect.

The SLK Black is much more than a styling exercise. It demonstrates that Mercedes can build machines which corner nearly as quickly as they accelerate – and that the subtleties of designing a capable sports car to satisfy enthusiasts is not beyond the firm.