Power for the roadster comes from a new naturally-aspirated AMG 5.5-liter V8 engine that delivers 62 more horses and 30Nm more torque than the previous model's eight-cylinder unit, at 422-horses and 540Nm in European-spec, and 415-horses at 6,800 rpm and 398 lb-ft at 4,500 rpm in North American-flavor.
The aluminum V8 engine also features the AMG Cylinder Management system that can shut off four-cylinders from 800 to 3,600 rpm to improve fuel efficiency.
A 7-speed AMG Speedshift automatic transmission featuring three modes (sport, manual and efficiency) transfers power to the rear wheels.
According to the Mercedes, the new SLK 55 AMG completes the standard 0-100km/h (62mph) sprint in 4.6 seconds and reaches an electronically limited top speed of 250km/h (155mph).
The roadster returns a combined fuel consumption of 8.5 lt/100 km, which is 3.5lt or 30% less than that of the preceding model with the 360HP V8.
