It's doubtful that Tobias Moers, the chief engineer at Mercedes Benz's AMG performance division, has ever watched an American sprint car race. He's probably never even heard of the World of Outlaws series either, let alone listened to one of the winged racers sliding around a dirt track with its 900-horsepower Chevy small-block screaming at wide-open throttle.
Mr. Moers knows exactly what it's like, though, and there's no doubt he likes the sound. It's obvious when you drive the 2012 Mercedes-Benz SLS AMG Roadster. That's because Mr. Moers personally signs off on the final exhaust tuning of every AMG vehicle, and although the new SLS is a nearly $200,000 luxury car, it also rumbles, spits and crackles like a tube-framed dirt tracker when you drive it just right.
It's his finest work to date. The rest of the car isn't bad either.
Clipping the Wings
Removing the gullwing doors from what is often referred to as "the gullwing Mercedes" is tricky. Retaining the car's distinctive styling was one obvious problem along with the usual structural issues that come with removing a car's roof.
With that in mind, Mercedes engineered the SLS from the start as both a coupe and a convertible. This meant fewer changes and less weight gain when the roof came off and the reinforcements were added. Upgrades include extra support struts for the dashboard, thicker-walled side sills and an additional strut that sits below the soft top and above the fuel tank to help reinforce the rear axle. Together with the various roof mechanisms, the SLS roadster weighs 3,660 pounds, or 88 pounds more than the coupe.
Also worthy of note is an additional brace made from carbon fiber mounted behind the seats. It supports the rollover protection system and it's the first all carbon-fiber part on a regular production Mercedes-Benz passenger car. Ola Kallenius, the CEO of AMG, told us that it's a hint of what's to come, as the all-new SL roadster that debuts next year will have its entire interior shell made of the lightweight material.
Better-Looking Than the Coupe?
As far as the styling goes, it was a smooth transition. The 2012 Mercedes-Benz SLS is one of the few convertibles that looks good with the roof up. And when it's down, there are plenty who would argue it's even better-looking than the coupe.
There's also the fact that the roadster's more conventional front-hinged doors make it a much more usable car. It's not quite a valet star like the coupe, but you also won't look like a klutz getting in and out of it.
The top moves quickly, too, taking just 11 seconds to open or close. It works on the move as well, so you can decide to put it up or down at speeds up to 31 mph. There's almost no intrusion into the trunk either, so even with the top down the cargo room in the trunk is nearly identical to the coupe at 6.1 cubic feet versus 6.2.
From Cruiser to Crushingly Fast
So there's not much of an advantage to putting the top up and plenty of reasons to keep it down. Listening to the 6.2-liter V8 mounted up front is reason enough to keep it down all the time. The hand-built engine is unchanged from the version found in the coupe, so it's still a naturally aspirated, dry-sump setup that delivers 563 hp and 479 pound-feet of torque.
Driven lightly, the big V8 keeps its capability under wraps. You don't hear much more than a low drone at cruising speeds, and most bystanders won't notice enough to even turn their heads. "It has to be comfortable even after driving for several hours," Moers told us.
Getting a little more out of it requires nothing more than dipping into the throttle enough to get the seven-speed dual-clutch transmission to kick down a gear or two. When it does, the car immediately tenses up, wiggles its nose a bit and leaps forward with an angry wallop of V8 thunder that has to be felt to be believed. You don't expect it from such a car that's so refined otherwise, and that's what makes it great.
The numbers back up the seat-of-the-pants feel, too. Mercedes claims a 0-62-mph time of just 3.8 seconds, so it's not just a bunch of noise from a raspy exhaust. If you care, the top speed is still 197 mph.
Not Quite a Sports Car
All the chassis reinforcements work well, too, as the 2012 Mercedes-Benz SLS Roadster is plenty stiff when you toss it around. Well, make that steer it around, as the SLS is really too big to fling about like a true sports car. At 76.3 inches wide and 182.6 inches long, narrow roads feel even tighter than usual. The steering is also on the light side, so it doesn't encourage you to test its limits the way a stiffer, more direct setup might.
A new AMG Ride Control feature offers three levels of suspension damping to go along with the three-mode stability control system. It's a typical system in that you don't feel a huge difference during normal street driving or even moderately quick canyon roads. With its all-aluminum double-wishbone suspension and standard 19-inch wheels and tires in the front and 20s in the back, the SLS is already well endowed before you start playing with the shock valving.
It's a similar story with the brakes. There's an optional carbon-ceramic setup available, but when the standard units are already massively capable it seems like overkill. There are six-piston fixed calipers in front and four-piston fixed calipers in back, so you get a firm pedal and plenty of power with the standard steel setup.
Speaking of Overkill
There's another new feature being introduced on the 2012 Mercedes-Benz SLS Roadster called AMG Performance Media. Press the "AMG" button and the dashboard display lights up with all sorts of vehicle information. There's a torque meter, a lateral-g meter, individual tire pressures and even a 0-60 timer. It's all a bit over the top for a car that's so unlikely to ever see a racetrack, but that rarely deters the AMG guys. They like to think of their customers as serious drivers first, so it's not surprising to see this level of data access.
Thankfully, the rest of the interior retains all the richness of the coupe. The seats are fantastic if you're on the thin side, a bit less so if you're any wider. Legroom is also at a premium if you're much over 6 feet tall. At least putting the top down makes the cockpit feel bigger, even if it's still a tight squeeze for two.
The AMG Issue
Like so many AMG cars before it, the 2012 Mercedes-Benz SLS AMG Roadster is an odd mix of luxury and raw performance. In this instance the performance is even more shocking given its convertible configuration and the kinds of buyers it's likely to attract. As much as AMG would like to think of its buyers as serious enthusiasts, it's silly to believe that most SLS roadsters won't be purchased as driveway jewelry.
Can't really blame those with the means for doing it either. It's plenty comfortable, easy to get in and out of and makes the iconic Mercedes SL look plain in comparison.
After driving it, though, we think it's better suited to a true enthusiast who knows that there's more to the SLS than those gullwing doors; someone who might stiffen up those dampers every now and again and turn off the stability control when no one is around. It would be a shame for Mr. Moers' handiwork to go to waste, and unless you drive the 2012 Mercedes-Benz SLS AMG Roadster like a racecar, you're missing out on half the fun.
Edmunds attended a manufacturer-sponsored press event to facilitate this report.
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