Mercedes-AMG GT S Roadster added

Benz fattens up its GT roadster range with GT S

Mercedes-AMG has added middle-ground punch to its hotshot two-seat GT convertible line-up.

The new Mercedes-AMG GT S Roadster should be just the thing for biturbo V8 lovers for whom a 302km/h blow dry is just not enough and a 316km/h blow dry is just too much.

The Mercedes-Benz hot-shop has released a 384kW/670Nm version of its front-engined 4.0-litre GT Roadster or, in simpler terms, cut the roof off its GT S Coupe to make a new roadster.

Sitting between the GT Roadster and the hottest GT C Roadster, the GT S will rip to 100km/h in 3.8 seconds on its way to a 308km/h top speed.

While pricing hasn’t been announced, it will slice the middle ground between the two existing GT-based roadsters but is likely to trend towards the heaviest hitter.

Critically, though, it won’t score the GT C Roadster’s rear-wheel steering system that adds the last touches to the flagship roadster’s handling performance.

In most other areas, though, the GT S Roadster favours the top-end roadster’s mechanical layout to that of the stock version.

The standard GT Roadster uses a fixed spring and damper package, a mechanical limited-slip differential, 19-inch rear wheels, a fixed exhaust system and four driving modes.

The GT S version steps that up to five driving modes by adding a Race mode, then dives into the GT C’s parts bin for pieces like its active sports exhaust, electronically controlled limited-slip differential, adaptive dampers and bigger composite brakes.

Where the GT uses 360mm front composite discs and 360mm integrated rears, the GT S steps that up to 390mm front and 360mm rear composite discs.

It won’t quite have the footprint of the GT C Roadster, though, with 295/30 R20 rear tyres compared to the faster car’s 305/30 R20s, though the front rubber is identical.

“With the AMG GT S Roadster, our AMG GT family has gained another exceptionally sporty member that combines high driving dynamics with an emotional open-air experience,” said Mercedes-AMG chairman Tobias Moers.

“The new model represents the perfect alternative for the performance-oriented AMG GT Roadster customer.”

But the perfect alternative to what: The GT or the GT C?

Its 384kW of power from the ‘hot-vee’ V8 is almost a neat halfway house between the stock car’s 350kW (though, at 6250rpm, it needs another 250 revs to claim it) and the GT C’s 410kW. It’s almost like they planned it that way all along.

Its 670Nm of torque is 40Nm up on the GT Roadster and just 10Nm shy of the heavy hitter, and holds a flat line between 1900 and 5000rpm. That’s the same torque delivery plateau as the GT, though the GT C hangs on to its peak torque for 500 more revs.

While the GT C suggests it’s a faster bullet than the GT S, it’s only a 10th of a second quicker than the new car to 100km/h and 0.4sec tenths up on the entry version.

But the GT C’s real strength has always been its cornering brilliance and the GT S only misses on one key piece of the handling suite and is lighter, too.

At 1625kg (DIN), it’s 30kg heavier than the GT and 35kg lighter than the GT C (with the faster car’s extra weight almost all in the rear-wheel steering system).

All three models use AMG’s seven-speed dual-clutch transmission to navigate their power towards the rear differential.

All three cars share the same spaceframe aluminium chassis and the same aluminium double wishbones all round, which is a far cry from the steel chassis of the four-door GT Coupe that AMG is about to launch, though they share the same badge.

There’s no guarantee that AMG will stop at the 12 models now available in its GT family with the addition of the GT S Roadster.

The range sits at four coupes, three roadsters, three four-door coupes and two customer race cars.