Its hard-top counterpart has gull-wing doors (they flip up rather than out), in tribute to the Mercedes-Benz 300SL coupe of the 1950s, a successful – and singularly beautiful – race and road car. So ditching one of the key design features and replacing them with a three-layer fabric roof is quite a bold step. But Mercedes-Benz tells us that the SLS was designed with both body styles in mind right from the get-go.
And that’s a good thing, because making a convertible out of a coupe often results in a compromised car. A metal roof acts as a structural member; without it, the body tends to flex and cannot provide a foundation firm enough for refined suspension settings. To compensate, car makers will add a load of bracing underneath, pushing up the curb weight in the process.
The SLS AMG Roadster has extra bracing, but AMG – the performance division of Mercedes-Benz – is too clever to fall into the fat trap. This model’s body has piled on only five extra pounds compared with the coupe’s. So it can still hit a maximum speed of 187 mph (electronically limited) without too much exertion. This roadster version could actually be the driver’s choice, since not having huge metal hinges in the roof should lower the car’s center of gravity significantly.
The roof is operated by an electro-hydraulic system that allows it to be opened or closed at speeds up to 31 mph (if this seems like an arbitrary number, it works out to 50 kilometers per hour). Its frame employs magnesium, aluminum and steel, for a balance of lightness and strength. And Mercedes-Benz has already tested it in that marvelously detail-oriented way typically associated with German engineers. This includes a hosepipe test, overnight rain test, going through a car wash, and a trip to Laredo, Texas, because there is some very fine dust in that region.
So far, the SLS has been the only car designed solely as an AMG model (the rest of the AMG range is based on regular Mercedes-Benz vehicles). Although the pictures do not show any three-pointed star badges on what is still a development version, they will be there in all their shiny glory when the car makes its official debut at the 2011 Frankfurt auto show in September. Soon after that, it will go on sale in the United States. For some kind of ballpark figure, the coupe currently starts at $183,000.