Supercar buyers are not very forgiving of yesterday's heroes.
They consider 2010 a long time ago, which is one reason Mercedes-Benz felt the need to develop a stronger and faster GT version of its already over-the-top SLS supercar.
Available in both coupe and roadster body styles, the 2013 Mercedes-Benz SLS GT delivers a touch more power than the standard SLS AMG but that's not its main selling point. For once, its rumbling, burbling, howling AMG engine isn't the centerpiece.
Instead, the core of the GT's upgrades is centered on changes to the seven-speed transmission and a reworked suspension. There are visual changes, too, but the SLS is hardly a car that needed more visibility, so they are understandably subtle. And given that the GT takes over as the sole model in the U.S. lineup, it's probably better that AMG didn't get too radical with the changes.
Just a Bit More Engine
Like few other cars on the market, the SLS is dominated by its engine. The 6.2-liter V8 feels like a masterpiece of American hot-rodding brutality stuffed inside the best of European chassis engineering. The GT doesn't do much to tweak that mix.
The only major upgrade to the engine is a bigger intake manifold, but AMG claims it's enough to help make another 20 horsepower, which lifts its rating to 583 hp at 6,800 rpm. Torque is unchanged at 479 pound-feet from 4,750 rpm. The result is a 0-60 spring that drops by a tenth to 3.7 seconds. It goes on to hit 124 mph 7.5 seconds later on its way to a 198-mph top speed.
Yes, it goes, something you might already presume from the way the SLS GT looks. But it's the sound that lulls you into believing the GT has an extra 300 horses on board. It's a tough thing to feel 20 hp in a car that already has plenty. In this case, it feels every bit as quick as it ever has, without feeling appreciably different.
The Big Switch
The biggest improvement doesn't come from the engine, though; it comes from the transmission. AMG's seven-speed gearboxes are a combination of heavily reinforced standard Mercedes-Benz torque-converter automatics with the torque converter bits taken off the back and replaced with computer-controlled clutch packs.
Compared to cars like the Ferrari 458 Italia (whose dual-clutch transmission was actually rejected by AMG) and the McLaren MP4-12C, the SLS used to take a bit too long to react whenever the driver pulled the + paddle in Manual mode.
The AMG engineers have attacked the problem of less-than-ideal shifts with a combination of software tweaks and some fine-tuning to the clutch pack. There's now less hesitation than before, so it now switches gears more or less when you ask it to.
Now, the SLS GT slams up to the next gear in 60 milliseconds, or about half the time it took the previous SLS to do the same job.
AMGs have always combined dripping luxury with outrageous straight-line performance, and the SLS is no different. But the GT has taken one option away that knocks it down a notch on the luxury scale in return for better performance.
We're talking about the "Comfort" mode of the adjustable suspension. That means the SLS GT has only Normal, Sport, Sport + and Manual modes, and these modes cover the suspension damping, the ESP behavior and the throttle response. Just in case you miss the point, it runs slivers of rubber on 19-inch wheels at the front and 20-inch wheels at the back.
Still, if it's comfort you want out of an SLS GT, you might as well take the Roadster. Its sills are lower and it has conventional doors, so it's easier and far more dignified to get into and out of. And its trunk is only a six-pack shy of the Gullwing coupe's.
Harder, but Not Always Better
It's hard to actually say whether the 2013 Mercedes-Benz SLS GT is a better road car. In some ways the new transmission's behavior makes it a no-brainer. In other areas, the lack of a Comfort mode makes it far less usable as a daily driver.
There is none of the jerkiness the previous SLS's clutches delivered when you're working your way out of parking lots with a cold gearbox. There are no snappy, wobbling shifts from 1st into 2nd on part throttle, either. It feels a lot more like a developed unit than it ever did before.
On the flip side, the suspension is edging toward the crude side. Never a gentle ride, the SLS GT is a very firm car — almost uncomfortably so on broken city streets. Sure, there's more grip on offer at the extremes of handling, but there are so few chances to exploit that it seems wasteful. It's a similar story with the brakes. They're fine in standard form, but opting for the carbon-ceramic discs will be a waste of cash for most people.
None of the minor shortcomings make this SLS any less spectacular on a proper road, however, as it moves with stunning speed and quickness that belies its considerably size. You find yourself changing down gears with absolutely no need, just to hear the engine pop and rumble. The Italians may have the high-pitched thing down pat, but AMG has carved its own sound path and it works.
All or Nothing
In Europe, Mercedes plans to continue selling the standard SLS alongside the harder-edged SLS GT, while in the U.S. it's an all-or-nothing deal. You either go all-out for the SLS GT or step down to the far less radical SL.
Problem is, as good as the GT can be on a perfect road, it's far less enjoyable nearly everywhere else. We would call it a track car, but track cars that cost nearly $200,000 usually have numbers painted on the side and much less leather.
So in this case, the 2013 Mercedes-Benz SLS GT is actually a track car for those who don't go to the track that often, if ever. Good bragging rights maybe, but best to have an S-Class around for when you need to get somewhere without spilling your coffee.
Edmunds attended a manufacturer-sponsored event, to which selected members of the press were invited, to facilitate this report.
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