New Mercedes-AMG GT R Roadster spied testing on track

Mercedes-AMG is testing its most hardcore drop-top yet at the Nürburgring, the AMG GT R Roadster, ahead of an expected sales debut next year.

The GT C Roadster is currently the flagship convertible in the Mercedes-AMG GT range and Mercedes-AMG was previously undecided on whether to go one further with an R version. That decision looks to have been made, however, since prototypes have been spotted lapping the fearsome German circuit. 

It’s clear that the roadster variant will adopt much of the GT R coupé's aerodynamic package, including the active airflow vents behind the grilles. The recognisable rear wing features, too, as does the rear diffuser. 

Expect the GT R Roadster to mirror its coupé sibling in terms of its powertrain, too, with AMG’s 4.0-litre ‘hot V’ eight-cylinder unit tuned to produce 577bhp and 516lb ft of torque. 

The roof mechanism and structural additions are expected to add only around 35kg to the kerb weight, so the roadster model shouldn’t stray too far from the coupé’s 3.6sec 0-62mph time. The worsened aero profile of the roof may reduce the 198mph top speed, however. 

The GT range's chassis design means that losses in structural stiffness are already kept to a minimum in the GT C Roadster. Nevertheless, it's possible that engineers may tune the Porsche 911 Turbo S Cabriolet rival's set-up differently to the standard car to reflect the lack of a roof.

The new car will be the fourth drop-top - and the eighth variant - in the AMG GT line-up when it arrives in 2019. It’s likely that its arrival will coincide with a full range update, bringing along a new cabin design inspired by Mercedes’ latest passenger cars.