Teased earlier this week, the Mercedes-AMG GT Roadster has been revealed. As expected, it’s a convertible version of the GT, but there’s a new variant too – the AMG GT C Roadster gets some goodies from the GT R and has power levels that are in between the standard AMG GT and the GT R.
Like its fixed top sister, the AMG GT Roadster is powered by a 4.0 litre twin-turbo V8 engine, with drive going to the rear wheels via the AMG Speedshift DCT seven-speed dual-clutch transmission. The standard car puts out 476 hp and 630 Nm at 1,700 to 5,000 rpm. The AMG GT C Roadster takes things up a notch, to 557 hp and 680 Nm at 1,900 to 5,750 rpm.
That’s an extra 81 hp/50 Nm in the bag. The AMG GT R has 585 hp and 700 Nm, so the C isn’t too far off, just 28 horses and 20 Nm. Compared to the fixed-top AMG GT S, the C has 47 hp more. The order is S, C, R. The standard roadster does 0-100 km/h in 4.0 seconds, with a top speed of 302 km/h. The GT C is three tenths faster to the clock and tops out at 316 km/h.
AMG has also adapted the DCT to the new power level of the GT C by modifying hardware and software. The first gear has a higher ratio, while seventh gear and the final drive have a lower ratio. This makes for “even more agile acceleration and very fast responses to sudden accelerator movements.” The AMG performance exhaust system with two adjustable flaps is standard on the C.
The GT C Roadster also gets R goodies like active rear axle steering (below 100 km/h, the rear wheels are turned in the opposite direction from the front wheels; above 100 km/h, all wheels point in the same direction) and the electronically controlled rear axle locking differential (mechanical locking diff in the standard car). The car also gets AMG Ride Control sports suspension, with adaptive damping not available in the non-C.
There’s more. The top roadster follows the AMG GT R where muscular proportions are concerned – its 57 mm wider rear wings accommodate a wider track and wider wheels at the rear axle. Rubber sizes are 265/35 R19 in front and 305/30 R20 at the back, versus 255/35 R19 and 295/35 R19 for the regular Roadster.
The GT C is also equipped with a lithium-ion battery, and has more exclusive appointments. Standard features include a nappa leather interior, the AMG performance steering wheel in nappa leather/Dinamica microfibre and the extra Race transmission mode (in addition to C, S, S+ and I).
To the roof. The fabric roof opens and closes in around 11 seconds, and can transform at speeds of up to 50 km/h. Three soft top colours of black, red and beige can be chosen to suit the 11 exterior and 10 interior colours. The three-layered fabric is supported by a magnesium/steel/aluminium structure of low weight, which helps to keep the centre of gravity low. Additional rollover protection is provided by an integrated aluminium cross-member with rollover bars.
The structure has been reinforced further to compensate for the lack of a roof. Side skirts with thicker walls and more chambers make the structure more rigid; the dashboard support is braced against the windscreen surround by additional struts, and a strut tower brace between the soft top and the tank reinforces the rear axle; while a cross-member behind the seats supports the fixed roll-over protection system.
The boot lid is particularly light, thanks to a new composite material. The load-bearing structure is of SMC (Sheet Moulding Compound) with carbon fibres, a high-tech plastic that’s light and strong, with a great surface condition. The material combo is used for the first time in the AMG Roadster.
The open top GT adopts the active air management system from the GT R. Vertical louvres located in the lower area directly behind the front fascia can be opened and closed by an electric motor in around one second. This ensures that the cooling performance is according to need. During normal driving with no increased cooling requirement, the louvres are closed to reduce aerodynamic drag and direct the air to the underbody.
Inside, the optional AMG performance seats can be had with the Airscarf neck-level heating system (three stages of warm airflow can be set) and climate control for the first time. The Burmester sound systems (two grades are available) benefit from the new Externed Coupled Subwoofer bass sound reproduction system.
Instead of a subwoofer box of limited dimensions, ECS uses the entire interior as a bass box. This is made possible by a special aperture in the right rear wheel arch. The subwoofer is connected to the bodyshell via this aperture. An “extremely low bass range” is the result.