The GT C is a completely new variant, with a unique engine tune and some of the running gear from the hi-po GT R.
Producing 410kW of power and 680Nm of torque from its 4.0-litre twin-turbo V8, the flagship GT C Roadster is 35kW more powerful than the GT S and 20kW short of the GT R, making it something of a bridge between the ‘S’ and ‘R’ variants.
With that extra power, the GT C Roadster is actually quicker than the GT S coupe despite its 15kg heftier kerb weight (1660kg), completing the 0-100km/h sprint in just 3.7 seconds (0.1 seconds faster) on its way to a higher top speed of 316km/h (up from 310km/h). Now imagine that with the roof down.
Like the GT R, the GT C features four-wheel steering and an electronically-controlled locking rear differential.
Also unique to the flagship roadster is adjustable AMG Ride Control sports suspension, 19-inch front/20-inch rear tyres, wider rear track, lithium-ion battery, nappa leather interior, nappa leather/Dinamica microfibre AMG performance steering wheel and an additional ‘Race’ transmission mode.
Visually, the GT C in the images borrows the ‘Panamericana’ 15 vertical slat front grille from the GT R, along with a similar bumper design with larger air intakes and deeper side skirts.
Around the back, the GT C gets the wider rear bumper with air outlets like the GT R, along with the additional air outlet under the boot lid. However, the GT C roadster retains a similar lower diffuser design to the GT and GT S coupes with dual exhaust outlets, in contrast to the GT R’s rear aero package that also features centrally-mounted exhaust tips.
Meanwhile, the ‘standard’ GT Roadster uses a slightly less powerful version of the company’s twin-turbo V8, producing a respectable 350kW of power and 630Nm of torque - 10kW and 30Nm more than the GT coupe that isn’t sold here.
The 0-100km/h run takes 4.0 seconds, on its way to a top speed of 302km/h, matching the GT coupe’s sprint to triple figures, but 2km/h short of the metal-roofed variant’s top speed.
Both the GT and GT C are fitted with a seven-speed DCT transmission sending power to the rear wheels.
Helping the Mercedes-AMG roadsters to achieve these performance figures are numerous modifications to the body to compensate for the lack of fixed roof.
A various mix of materials in the body structure - including aluminium alloys in the chassis and magnesium for the front deck - help to make the vehicle more nimble in corners.
The body has been reinforced using thicker side skirts and extra dashboard support struts, along with a strut tower brace between the soft top and the fuel tank to reinforce the rear axle.
A cross-member behind the seats supports the fixed roll-over protection system built into the roof mechanism.
Inside, the GT and GT C are largely the same as their coupe siblings, albeit with the obvious difference of the folding fabric roof - which is available in black, red and beige.
The electrically-operated roof can open and close in around 11 seconds at speeds of up to 50km/h.
Optional on the GT and standard on the GT C is the AMG performance exhaust system, which features variably-adjustable flaps to deliver a more “emotive” soundtrack depending on the selected driving mode. Alternatively, the flaps can be opened or closed using a button on the centre console.
The seven-speed DCT transmission also comes with three transmission modes in the GT Roadster; Comfort, Sport and Sport Plus. The fourth ‘Individual’ setting allows drivers to tailor their driving experience to their liking.
Additionally, the GT C gains the aforementioned ‘Race’ mode, which sharpens shift times even further and opens up the exhaust for the full-fat twin-turbo V8 soundtrack.
Both AMG Roadsters feature the GT R coupe’s active air management system, which involves electrically-operated louvres in the front grille that can be opened and closed in around one second.
With the louvres closed, aerodynamics are improved, conducting air to the underbody. However, when certain components require more air, the louvres open to allow maximum airflow to the heat exchangers.
While the GT C specification is currently limited to roadster form, a product roadmap revealed earlier this year indicated the company's plans to release a coupe version sometime later next year.
The company’s local arm has confirmed that it will launch at least the GT C Roadster in the second half of next year.
It’s unknown whether Mercedes-AMG will bring the standard GT Roadster to Australia, however, as the GT coupe didn’t make it to local showrooms.
Final pricing and specification details will be revealed closer to launch, though further details should be obtained at the Paris motor show next month, so stay tuned to CarAdvice for more Mercedes-AMG GT and GT C Roadster updates.
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