Mercedes-Benz SLK 55 AMG: Special Series

Motoring Channel Staff - 12/June/2006

Until BMW's next generation M3 and M4 models hit the scene - expected to break cover later in 2006, perhaps September at the Frankfurt Motor Show in Germany - the only 8-cylinder roadster in the segment is the Mercedes-Benz SLK 55 AMG.

The increasingly popular two-seat roadster is now even quicker than before, in what some are calling a pre-emptive strike against BMW's as yet unseen M3 drop top, itself expected to feature a compact, high revving 294kW/400hp V8 engine.

Mercedes says that it's performance arm, AMG, has developed an exclusive and distinctly puristic special series which sets new standards in driving dynamics, but how has this been achieved? With a range of upgrades that alter both the engine and the chassis.

The first change occurs with the AMG 5.5-litre V8 engine, which according to the company has been enhanced to 294kW (400hp) and 520 Newton metres.

A modified air intake, AMG sports air filter as well as newly developed fan-type exhaust pipes provide an efficient gas cycle and enable that the 8-cylinder reacts more promptly to accelerator pedal movement – which is acoustically noticeable.

In addition to the increased power, numerous lightweight construction components improve the vehicle's power-to-weight ratio, such as a a carbon hardtop and 19-inch AMG forged wheels. An AMG height-adjustable torsion sports suspension and AMG high-performance composite brake system also boost the chassis' response explains Mercedes, making it just as viable on the tracks as on the public roads.

The combination of a lower vehicle weight and a high-performance AMG naturally aspirated 8-cylinder engine guarantees first-class driving performance: the acceleration from zero to 100km/h requires only 4.5 seconds, which compares well with the standard vehicle's 4.9 seconds. Other performance benchmarks include the 0-200km/h dash, which takes 15.5 seconds, a good 2.0 seconds quicker than the standard vehicle, at 17.5 secs.

Power mediation between the engine and the rear wheels is controlled by the AMG SpeedShift 7G-Tronic gearbox, featuring a manual drive program and AMG aluminium shift paddles on the steering wheel.

Mercedes-Benz is keen to highlight it's sporty 2-seater's sporty image, calling it wide, stocky and low slung. The front of the car features a restyled AMG front apron with large air intakes that supply the additional transmission oil cooler and the high-performance steering gear oil cooler with sufficient fresh air.

New side air outlets of black carbon ensure an effective flow through of the larger engine oil cooler, while adding another area of visual interest. The front wheel arches (now wider) are made of the ultra-light carbon-fibre-reinforced-plastic (CRP) and have black out-lined air outlets.

The non-retractable hardtop of the two-seater is also made of CRP; the black central part with carbon fibre structure provides attractive optical effects. Mercedes also explains that by discarding of the vario roof (including the hydraulics) the car's centre of gravity has been lowered, and a notable reduction in weight was also achieved. For a Mercedes-Benz, this vehicle is quite skinny - the SLK 55 AMG has with a kerb weight of 1495kg. This means that the power/weight ratio has improved from 4.3 to 3.7 kg/hp.

Mercedes also reckons the chassis and brake system are the ideal partners for the beefed up drive package. For example, the AMG height-adjustable torsion suspension, including adjustable shock absorbers, has been optimised on the racetrack, catering for radical cornering speeds. Mercedes has also revealed that a brace in the engine compartment provides additional rigidity and more lateral dynamics to the car, which sits on ultra-light AMG forged light alloy-wheels with tyres in sizes 235/35 ZR19 (front) and 265/30 ZR19 (rear). As an alternative, optional special sports tyres are available without extra charge, while uprated levels of deceleration are guaranteed by the AMG high-performance brake system, featuring larger composite discs on the front axle.

Mercedes-Benz and it's performance tuning group, AMG, have also spent time and money on the interior of the new Special Series SLK 55 AMG. First and foremost, two specially developed AMG sport bucket seats (without side airbags) offer the best lateral support in the cockpit says Mercedes, while a new AMG ergonomic sports steering wheel in leather and Alcantara enables perfect control of the vehicle. Ample carbon fibre on the door panel lining as well as on the trim parts give the interior the functional atmosphere of a real racing car – and are an affirmation of the almost 40 years of Mercedes-AMG motor sport history.

The first models of the unlimited AMG Special Series will be supplied to customers as of July in Europe, good six months before BMW is expected to release it's 8-cylinder M3, which will rival the new AMG model, not to mention vehicle's such as the Audi S4. The price in Germany is €107,300, which translates to about $A180,000.