Compared with the old SL, the new Mercedes-Benz SL is much longer and wider.
Oops! Press leaks about the new Mercedes-Benz SL has apparently prompted an extensive official release of the all-aluminum sports car ahead of its official introduction at the North American International Auto Show next month.
The SL designation, for sporty lightweight, has had a long successful run for Mercedes going back to the original 1952 SL with its lightweight tubular frame. On the new SL, Mercedes-Benz will use an all-aluminum body in a mass-production model, although previous limited edition AMG SL models had an aluminum body. The body weighs ~242 pounds less than it would using the steel technology of the SL it replaces – currently selling in the $104,000 to $144,000 range) when the 2013 SL550 appears in U.S. showrooms this spring.
The sixth generation SL has a retractable hard top that is activated via an electro-hydraulic mechanism, converting SL from coupe to roadster.
“The effect is as if a large passenger has stepped out of the car” says Dr. Thomas Rudlaff, responsible for the aluminum body at Mercedes-Benz. “The result is perceptible and measurable. Less weight means improved performance and efficiency. In other words, the driving pleasure increases and the environmental impact decreases.”
Few components are not aluminum, according to a Mercedes release. Engineers used lighter magnesium for the cover panel behind the fuel tank and roof. In sum, the new SL is 275 pounds lighter than the old one – key to improving fuel efficiency. However, high-strength steel tubing is integrated into the A-pillars for added safety during rollovers.
A new V8 engine in the SL550 develops 429 horsepower from its displacement of 4.7-liters, about 12% more than its predecessor with 0.8 liters less displacement. Fuel consumption has been reduced while at the same time the torque has increased from 391 lb-ft to 516 lb-ft – a gain of 32%. The engine has a stop/start system as standard equipment, and is mated to a 7-Speed automatic transmission.
Nevertheless Mercedes claims the fuel economy of the direct injection engine does not detract in any way from the roadster’s performance – the SL550 takes just 4.5 seconds from 0 to 60 mph – eight tenths less than the previous SL550.
