February 2009

Mercedes-Benz SLK-Class SLK55 AMG

AMG enhancements make the SLK hard to miss

February 2009

picture of car from the frontpicture of car from the rearpicture of car interiorpicture of car in detail

Overall rating

4.0 out of 5 stars


  • V8 engine is flexible, powerful and sounds superb
  • Visual changes make the most of the SLK's shape
  • Interior is cosy but a pleasure to use
  • Suspension delivers impressive handling


  • ESP is a little restrictive even when switched off
  • Both cabin and boot are relatively confined
  • Running costs likely to be high
  • No manual gearbox option with V8 engine

By paying close attention to mechanical changes and enhancing the specification, Mercedes-Benz turned the SLK from a handsome roadster into a genuine sports car and put the competition under pressure in the process. The red-blooded SLK AMG has always has plenty of power, but can those same revisions help it to take on the best high performance competition?

Building on the success of the SLK model, the AMG version brings the traditional mix of high performance, improved dynamics and menacing looks to the metal roofed roadster. The legendary AMG badge marks out the most performance-oriented cars in the Mercedes-Benz range, usually with an exciting multi-cylinder engine under the bonnet.

The heart of the AMG version is the 5.4-litre engine, unchanged over the outgoing car. In this installation it also uses the seven-speed automatic transmission, and with the paddleshift option it brings a great deal of control, allowing the driver to exploit the engine's performance, whether using maximum revs or exploiting the large reserves of torque.

Changes are relatively modest compared to the last iteration of the SLK AMG, but importantly it benefits from the same mechanical changes made to the standard car, the key element of which is the sharpened steering action. It only takes a few twirls of the wheel to feel how much more responsive it is, which bodes well for enthusiastic driving.

Distinguishing the AMG version from the regular SLK are a number of exterior enhancements, including an F1-inspired front end, side skirts and a chunkier rear bumper. A twin exit exhaust and rear spoiler complete the exterior changes, giving the AMG version considerably more presence than the standard version.

Our verdict on the Mercedes-Benz SLK-Class SLK55 AMG

As an improvement over the standard model, the SLK 55 AMG is a resounding success, building on the strengths of the original while adding to its sports car credentials. In practical terms it is far from perfect, but the high standard of build quality and specification makes it a car to be enjoyed.


The SLK 55 AMG is likely to be an expensive car to run, with high fuel bills, service costs and insurance. The purchase price is also inevitably high.

Space and practicality

The SLK scores less well in terms of practicality for, although the cabin is comfortable, there is not a lot of excess of room. The same can be said for the boot, which is awkwardly shaped despite holding 300 litres. Cabin storage areas are also relatively limited, demanding careful packing for a long trip.

Controls and display

The cabin of the SLK is certainly busy, but well laid out and easy to use. The instrument displays are clear and attractive, with comprehensive information displays between the main dials. Additionally, the steering wheel controls make it easy to operate the stereo, telephone and trip computer, while the centre console is neat and satisfying to use.


Although the AMG version is the most focused of the SLK range, it still provides a good level of comfort. Noise levels are well contained even with the roof down and the seats provide excellent support. The optional Airscarf system also blows warm air around the neck, keeping the occupants warm with the roof down even in cold weather.

Car security

Standard fitment is an alarm system with engine immobiliser and interior protection, allowing the car to be left roof down while the alarm is still active. It also has the option of remote closure of the roof via the keyfob, which is a useful feature.

Car safety

A comprehensive range of safety equipment includes ABS with brake assist, ESP, airbags and xenon headlamps, while the AMG adds the improved braking system and firmer suspension, both of which should help accident avoidance.

Driver appeal

The compact dimensions and folding roof are big plus points of the SLK, so when it is combined with the powerful 5.4-litre AMG V8 engine, it provides plenty of entertainment. There is a huge amount of torque on offer from low revs for rapid acceleration, with the paddleshift operation of the gearbox making it even easier to access the performance. The revised suspension provides excellent body control and grip, while the enhanced brakes are fade free and have large reserves of stopping power.

Family car appeal

With only two seats, the SLK's ability as a family car is restricted, as is the boot space: taller child buggies might not fit in the space. Children will undoubtedly enjoy the performance and the experience of top down motoring, but only the smallest families will find it adequate.

First car appeal

The SLK is a benign car when driven with restraint, but is likely to be too expensive for new drivers, as well as too powerful, and the high insurance is likely to rule it out for most inexperienced drivers.

Quality and image

Throughout the cabin the SLK exudes quality thanks to the soft touch plastics, fabrics and leather used in the cabin. The design is also modern and understated, making it a comfortable and appealing environment. In terms of image, the regular SLK is still seen as more of a convertible than a true sports car, but the AMG version has a strong cache of high performance, separating this version from the regular SLK.


Access to the front seats of the SLK is straightforward, although it is much easier with the roof folded down. With the roof up, the low roofline and seating position does require passengers to duck down as they enter. Access to the boot is again compromised by the roof position, as it is reduced significantly when folded down.

Stereo and ICE (In car entertainment)

The optional combined sat-nav/CD/tuner system has a high degree of functionality, including a six-CD/DVD changer and the option of Harman-Kardon surround sound and MP3 player connection. The sound quality is excellent and operating the system is straightforward.

Colours and trim

Even in standard form the SLK is well finished, but the AMG version gains carbon fibre interior trim. Alongside quality plastics and leather it gives the cabin a luxury feel. The choice of material colours also helps to give the cabin a lift, which can otherwise feel quite dark with a lot of black in evidence.


With the roof up, rear vision is quite restricted and, although the SLK has power steering and an automatic transmission which makes parking easier, the larger alloy wheels that come as standard are easy to kerb, requiring extra care when parallel parking.

Spare wheel

Space saver spare wheel fitted beneath the boot floor.

Range information

Petrol engine options - 1.8-litre (184bhp); 3.0-litre (231bhp); 3.5-litre (305bhp); 5.4-litre (360bhp). Transmission options: six-speed manual gearbox, five-speed automatic, 7G-Tronic seven-speed automatic. Trim levels: dependent on engine size.

Alternative cars

Porsche Boxster S Superb driving experience, looks may not suit all

Nissan 350Z Roadster Individual looks, great chassis and characterful engine

BMW Z4 M Roadster Amazing engine and performance, design divides opinion

Honda S2000 Styling still attractive, engine superb but interior a little dated

Over 1,300 car reviews online

Search for the make and model you fancy