Mercedes-Benz SLK 55 AMG review
The new Merc SLK 55 AMG has 422hp. Still think it's a car for hairdressers?
Graeme Lambert

Published on February 16, 2012

The latest roadster from Mercedes-Benz just got a whole lot better - fitted with a powerful and efficient V8 engine and benefitting from AMG's suspension know-how it's the best SLK yet. A great noise, impressive comfort, high levels of equipment, neat looks and of course that clever folding hard top make it an incredible all-rounder.


In the metal 4/5

Ok, I'll come straight out and say it, the SLK looks a little, well, hairdresser - sorry but, it's an image that the original coupé-convertible will always struggle to shrug off. Still, this new AMG model looks a little more DAX Wax than GHD straighteners, the 18-inch alloys and body styling kit adding some much needed aggression to the design.

There's still the classic roadster proportions underneath though, a long bonnet and short rump ticking the required boxes. In fact, from some angles, the SLK looks genuinely menacing - especially from the front where the LED daytime running strips and oversized three-pointed star make their appearance. And while many folding hard tops can look a little disjointed with their roof in place, the SLK arguably looks better this way.

Leaving the roof up would hide the interior though, which is pretty much standard fare for this top model. For some it just won't be different enough, but it's refreshing to see that restraint has been applied when it comes to labelling surfaces with the AMG logo. Of course the wheel is moving ever closer to being square with a flat upper and lower section, and the middle of the rim can be wrapped in Alcantara, while the centre console is swathed in a carbon fibre look material.

Driving it 4/5

If you're expecting this AMG-badged SLK to be some hardcore roadster best suited to the track then you're going to be sorely disappointed. The most powerful SLK ever is much more comfortable and refined than that and is best enjoyed on the flowing open road - preferably with some tunnels thrown in so you can enjoy the bark from the exhausts.

Ah yes, the noise - there's something wonderful about driving such a small open topped car with the rumble of a V8 under your right foot, and the new exhaust valves make it sing even louder than expected when pushing hard. Lift off the throttle quickly, and you're treated to a drum roll of pops and bangs on the overrun while low revs (like around town) makes it quietly civilised.

Hot-rod like roar aside, the SLK AMG 55 actually offers a much more rounded package than you might expect. The steering is well-weighted and provides acceptable feedback, and while the suspension is stiff (it's even firmer with the optional Handling Pack) it proves compliant on all but the sharpest of surface changes. Of course the metal roof makes itself known, up or down, and you can feel the weight shift when tackling a series of bends, the body rolling more than some of its fabric-roofed rivals. Still, in the dry there's plenty of grip, and only when really provoked will the rear end break loose and send the three-stage ESP system into any sort of panic.

With 422hp and 540Nm available it's no surprise that the SLK makes short work of any straights you decide to point it down - covering the 0-100km/h sprint in 4.6 seconds. The seven-speed automatic gearbox can be a little slow in the upshift right at the redline, even in sport or manual modes, but at all other times it's a picture of efficiency and smooth changing that we've come to expect from Mercedes' self-shifters.

But it's not just the performance that is exciting - this is the first Mercedes to use the firm's newly developed cylinder management system that shuts down four of the eight cylinders at low revs. The result is the SLK saves over 3.5mpg on the combined cycle, and the 5.5-litre engine can lay claim to being the most fuel efficient V8 in the world. There's a display nestled between the instruments that indicates how many cylinders are firing, and the beauty of the system is that, without this, neither driver nor passenger would actually notice.

What you get for your money 4/5

As a standalone special, the SLK 55 AMG is only available with one engine and gearbox combination. However, those craving a little more performance can opt for the Handling Package, which features stiffer suspension, a limited slip differential and composite front brake discs. There's also an Edition 1 available, which comes with an upgraded interior and choice of three exterior paint finishes including Satin White. One option box that should be ticked is the Airscarf neck heating system that blows warm air from the seat on occupant's necks to allow all-weather top down use of the SLK. The official price for the SLK 55 AMG in Ireland has been confirmed as €109,000.

Worth Noting

The naturally aspirated 5.5-litre V8 is actually based on the firm's bi-turbo engine of the same displacement, also found in the E 63 AMG, CLS 63 AMG, S 63 AMG and CL 63 AMG models. But the SLK ditches the forced induction, and uses new air intake manifolds, cylinder heads and oil supply system along with a stop-start function to bring about a 30 per cent improvement in efficiency over the old model - with a headline figure of 195g/km of CO2 output.


There's no doubt the Mercedes SLK 55 AMG is by far the best iteration of the roadster yet, offering performance and a noise that is beyond most of its direct rivals. It might not challenge a Boxster in the twisty stuff, but in almost every other discipline it proves to be an incredibly good all-rounder. In fact, despite my misgivings about its image, the SLK 55 AMG really is a car to let your hair down in and enjoy.


Tech Specs

Model testedMercedes-Benz SLK 55 AMG
Engine5.5-litre V8 petrol
Transmissionseven-speed automatic, rear-wheel drive
Body styletwo-door coupé-convertible
RivalsAudi TT RS Roadster, BMW Z4, Porsche Boxster S
CO2 emissions195g/km
Combined economy33.6mpg (8.4 litres/100km)
Top speed250km/h
0-100km/h4.6 seconds
Power422hp at 6,800rpm
Torque 540Nm at 4,500rpm