It’s five and a half feet long. It weighs 8.8 pounds. Height of an adult female, weight of a gallon or so of gas—these are the critical dimensions of the carbon-fiber driveshaft running between the engine and the rear-mounted transaxle in the new Mercedes SLS AMG. We note this here because, despite the car’s retro-gullwing looks, the SLS is utterly bleeding edge—both in terms of its technical attributes and what it represents for Mercedes’ in-house tuner. It is not simply a Mercedes with bigger wheels and a breathed-upon V-8 or V-12. It is, down to its churning carbon-fiber core, AMG’s first dedicated automobile and the very antithesis of the overly complex and overweight half-million-dollar Mercedes SLR McLaren.
“The SLS is a serious super sports car, ” says AMG chief of development Tobias Moers before taking a shot at the SLR, a carbon-fiber-bodied car that still managed to weigh in at 3858 pounds. “Our SLS weighs only 3572 pounds, ” he says, nearly 300 pounds lighter than the McMerc. Keeping the 182.6-inch-long, two-seat SLS’s mass in check is its entirely aluminum construction (save for that driveshaft and steel A-pillars), a first for Mercedes-Benz. The aluminum structure weighs just 531 pounds, Mercedes says.
The most distinctive aspect of the SLS’s appearance is, of course, its roof-hinged gullwing doors, an homage to the iconic 300SL Gullwing. But AMG personnel took pains to point out that the doors are the only thing the SLS has in common with the 300SL. “We do not build a retro car at all!” AMG boss Volker Mornhinweg explains sharply. “In fact, we think it is the most advanced super sports car you can buy today.”The M159 comes with an all-new magnesium intake, forged pistons in place of cast ones, and optimized tubular exhaust headers. The engineers also switched from a wet sump to a dry arrangement, allowing the engine to be mounted lower to benefit the SLS’s center of gravity. The maximum output of 563 horsepower is delivered at 6800 rpm, and peak torque of 479 pound-feet comes at 4750 rpm. /p table border="0" cellpadding="2" cellspacing="0"x">
In order to satisfy emissions standards—EU5, LEVII, ULEV—the Bosch ME 9.7 AMG engine management is set up to recharge the battery during deceleration. It’s another way of trying to eke out decent fuel economy, which, based on Mercedes’ European estimates, should equate to roughly 13 mpg city and 20 highway.
The SLS is the first Mercedes to use a new dual-clutch seven-speed transmission that was developed in conjunction with Getrag. This transaxle is mounted at the rear of the car and is connected to the engine by that carbon-fiber driveshaft. Perfectly executed blips of the throttle during downshifts not only make the shifts smooth, their bark could also break any nearby glass.