Mercedes-Benz’s sixth generation SL roadster that arrives next year is the first model from the automaker that enters large-scale series production with a nearly exclusive aluminum lightweight construction. Right before the Los Angeles motor show, Mercedes presented a completed example of the new two-seater grand convertible’s ‘body-in-white’ superstructure to journalists.
Built from a combination of chill cast-, vacuum die cast-, stamped- and extruded aluminum, the finished 2012 SL becomes 140kg lighter than the outgoing steel car. In addition, it is 20% more torsionally rigid. As a result, its handling precision, rolling refinement, performance and fuel-efficiency are all enhanced.
The automaker said that its CAD-optimized design for the SL’s monocoque is stiffer than its rivals that also use aluminum construction. SL Product Manager Bernd Stegmann said that the Jaguar XK has a body stiffness at around 16,000Nm per degree of torsional deflection.
In comparison, the new SL has slightly under 20,000Nm per degree. He added that various methods are used to connect the different metal castings and tailored blanks of the SL’s body-in-white.
This depends on how much load is transmitted. Several underbody parts are MIG welded, hemmed, bonded and bolted but others are joined with the use of highly advanced friction stir welding.
This technique results to very stiff, precise joins. This vehicle uses aluminum body panels primarily. Its only major parts that are non-aluminum are its pedestrian-protection-oriented plastic ‘soft nose’ grille, its super-lightweight magnesium rear bulkhead, and its tubular steel A-pillars and header rail. Steel (with its high strength) was selected in order to offer protection if there’s a rollover.
The Mercedes-Benz SL-Class bears the “SL” name, which stands for exciting design, effortless style, power, sportiness, technical superiority, and the ultimate in engineering artistry. For six decades, these two letters exude mystique among automotive buffs. Designed as a race car, the SL first made its entrance into the world of international racing in 1952.
From this car, Mercedes-Benz based its first series production model in 1954 – the 300 SL gullwing. Since then, the carmaker has been setting high standards in the luxury sports car segment, through five SL model generations.
Mercedes-Benz SL-Class is considered a dream car with its unique combination of sportiness, refined luxury, and unrestricted suitability for daily driving. What’s more, the SL is always considered to be ahead of its time, even with the fact that it rolls off the production line for 18 years at a time. Take for example the SL with internal code R107, which rolled off from 1971 to 1989.
More than 650,000 SL cars have already been produced in Sindelfingen and Bremen since 1954. And from the latest model generation alone, which premiered in 2001, almost 170,000 units have found homes with high-calibre sports car enthusiasts.
The new SL-Class is now the sixth generation SL and in the unique SL tradition, it is entering its era as an innovative trendsetter with refined looks, and a powerful athletic stance. Initially, Mercedes-Benz is offering its new SL with two engines: the SL500 with a V8 engine and the SL350 with a V6 engine. The new BlueDIRECT engines have an output of 320 kW (435 hp) for the SL500 and 225 kW (306 hp) for the SL350. These output figures represent a 12 percent increase over the new model’s predecessor.