As soon as we learned that Mercedes-Benz had commissioned its AMG performance division to build a Gullwing redux, we knew a convertible version wouldn’t be far behind. For one thing, its progenitor, the 1950s-era 300SL, was offered in both hardtop and roadster varieties (though never at the same time). Each was beautiful in its own right, and both are pricey collectibles today. And Mercedes-Benz itself repeatedly spilled the ragtop beans, at media gatherings that took place before the launch of the coupe, by dropping the yet-to-be-revealed car into a Super Bowl commercial, and by recently offering its own “spy” shots of the car. But only now has the complete body of information on autodom's worst-kept secret, the 2012 Mercedes-Benz SLS AMG roadster, been made public.
There are few surprises. We knew, for starters, that the convertible would be built around an aluminum space frame, just like the coupe. We figured that front hinged-doors and a cloth top would not contribute much additional weight, considering the complex doors and roof-mounted hinges on the coupe. Turns out we were right: At a Mercedes-claimed 3661 pounds, the roadster weighs just 88 pounds more than the company reports for the bewinged car. This is in spite of added bracing around the windshield, the rear axle, and the base of the doors, as well as an additional crossmember to support the fixed roll bars behind the seats. Mercedes-Benz claims that the space frame weighs less than five pounds more than its hardtop counterpart.
The frame for that top is composed of steel, magnesium, and aluminum, with the cloth skin presenting a profile that appears just as sleek as that of the coupe. We expect that shape will work well with the deployable trunk-mounted spoiler to help match the coupe’s high-speed aerodynamics. The three-layer top, which is available in black, red, or tan, may be raised or lowered in a scant 11 seconds at speeds up to 31 mph. Regardless of the top deployment, trunk space roughly matches that of the coupe, at a meager 6.1 cubic feet (versus 6.2 for the coupe).
Something else we knew before the official info release is that the SLS AMG roadster would get the same glorious, AMG-designed, 6.2-liter V-8 as the coupe, sending the same 563 hp at 6800 rpm and 479 lb-ft of torque at 4750 rpm to the rear axle via the same carbon-fiber driveshaft. Likewise, the coupe’s seven-speed dual-clutch transaxle serves as the roadster’s sole gearbox, with four driver-selectable shift modes and a “Race Start” launch-control feature (though we hope that AMG heard our cries for quicker shifts in manual mode). The standard vented and cross-drilled disc brakes and optional two-piece carbon-ceramic discs also are shared with the coupe.
The roadster will offer an optional active suspension with three-mode, driver-selectable adaptive shocks; the options are Comfort, Sport, and Sport Plus. According to Mercedes-Benz, the feature will be offered on the coupe in the future, although for now the roadster alone offers this upgrade over the standard suspension (which is already rather capable). With no powertrain changes of consequence, then, the roadster’s minor difference in mass and—presumably—weight distribution may only slightly affect its ability to match the coupe’s 3.5-second 0-to-60 time and 151-foot 70-to-0-mph stopping distance. Of course, we won’t know for sure until we strap our test equipment to it, but for the record, Mercedes-Benz states the SLS AMG Roadster’s 0–60 time as 3.7 seconds, and its top speed as a very breezy 197 mph (same as the coupe).
Thanks to: Car and Driver