Stuttgart - Mercedes is offering the super sports car SLR McLaren in an open-top version featuring a retractable soft top made to withstand high speeds.

Limited to 150 units, the basic version has a price tag of 517,650 euros (748,000 dollars), around 25,000 euros more than the standard version.

With an output of 478 kW/650 hp, the car accelerates from zero to 100 km/h in just 3.7 seconds and can reach a maximum speed of 335 km/h.

In addition to increased power, the new SLR McLaren Roadster 722 S features more dynamic suspension tuning and improved aerodynamics.

In addition to a higher engine output, the new SLR McLaren Roadster 722 S has a more dynamic suspension setup and further aerodynamic improvements, according to Mercedes.

By naming this new model variant the SLR Roadster 722 S, Mercedes-Benz is recalling the historic victory won at the classic Mille Miglia long-distance race in 1955 by British motor-racing legend Stirling Moss and his co-driver Dennis Jenkinson, in a Mercedes-Benz 300 SLR with the starting number 722.

At the heart of the SLR Roadster 722 S is a supercharged 5.5-litre V8 engine which is hand-built in the Mercedes-AMG engine shop in Affalterbach.

According to Mercedes the fully retractable fabric soft top still makes open-air conversations possible at speeds well over 200 km/h because of favourable aeroacoustics.

The soft top opens and closes semi-automatically in around 10 seconds, combining comfort expectations with the purist nature of the roadster. The roof has to be unlatched at the windscreen frame and lifted slightly to open it. It then folds down electrically. The front section of the soft top features an integral aluminium cap, which effectively prevents "ballooning" at high speeds. (dpa)