Wraps come off new Mercedes-AMG GT Roadster

Mercedes-AMG has revealed its new 316km/h GT Roadster in a series of official photographs ahead of a planned world premiere for the open top two-seater at the Paris motor show later this month.
 
Mirroring the strategy taken with the GT Coupe, the GT Roadster will be sold in two distinct versions when Australian sales get underway later this year: the 350kW GT Roadster and the more comprehensively equipped 410kW GT C Roadster.
 
Pricing is yet to be revealed, although Mercedes-AMG officials suggest the GT Roadster will be pitched around $20,000 above respective GT Coupe models. This should see the standard GT Roadster priced at close to $315,000, with the more powerful and comprehensively equipped GT C roadster likely to nudge $335,000. However, Australian deliveries are not planned to begin until the second half of 2017.
 
Sporting the styling updates unveiled on the 430kW GT R in June, the GT R Roadster features AMG's distinctive new 300 SL Panamericana inspired  grille, which receives an altered shape and vertical chrome bars instead of the earlier blade treatment seen on the GT Coupe.  
 
To ensure more efficient cooling of the engine and improved aerodynamic properties, the GT Roadster also adopts the active air management system that debuted on the GT R. It uses a series of vertical louvers within the grille, which automatically open and close depending on the temperature of the engine to either enhance cooling or smooth airflow.
 
Further visual changes over the GT Coupe include a more defined splitter element in the lower section of the front bumper, larger air ducts and more defined sills underneath the doors.
 
At the rear, the two GT Roaster models differ in width due to the adoption of differing rear fenders. The standard GT Roadster uses the same fenders as the existing GT Coupe, while the GT C Roadster uses the 57mm wider bodywork of the GT R.  This allows the latter to run larger 20-inch rear wheels with 305/30 profile rubber as standard in place of the 19-inch rims and 295/35 tyres of the former.
 
As with its successor, the SLS Roadster produced between 2011 and 2014, the GT Roadster features an automatic fabric roof. The three layer structure, which comes in either black, red or beige, is supported by a frame manufactured from aluminium, magnesium and steel. It opens and closes in a claimed 11sec at speeds up to 31mph, folding and stowing over the rear bulkhead behind the two seat cabin.  
 
Offsetting the loss of a fixed roof structure is a stiffened the aluminium body structure with thicker sill elements, an additional dashboard support and a new aluminium cross member supporting a fixed roll over bars.  
 
Significantly, the GT Roadster packs greater reserves than the GT Coupe to counteract the higher kerb weight brought on by its electrically powered fabric roof and the structural stiffening measures required to accommodate it.
 
The third model in the GT line-up shares its twin-charged 4.0-litre V8 petrol engine with AMG's headlining coupe. But while the 90-degree unit delivers 340kW in the GT Coupe and 375kW in the GT S Coupe, its output has risen a respective 10kW and 35kW, giving the GT Roadster 350kW and the GT C Roadster a heady 410kW.
 
Torque is also up on the GT Coupe, extending by 30Nm in both the GT Roadster and GT C Roadster to 630Nm at 1700rpm and 680Nm at 1900rpm respectively.
 
By comparison, the twin-turbocharged 3.8-litre horizontally opposed six-cylinder powered Porsche 911 S Turbo Cabriolet kicks out 425kW and 700Nm.
 
Together with the increase in power and torque, the GT Roadster also receives altered gear ratios for its seven-speed Speedshift dual clutch transaxle. AMG says the new open top features a higher first and lower seventh gears as well as a lower final drive than the existing GT Coupe.  
 
The rear-wheel drive GT Roadster offers four driving modes as standard via a so-called Dynamic Select controller: Comfort, Sport, Sport Plus and Individual. The more performance focused GT C Roadster adds a fifth mode: Race.
 
With a weight-to-power ratio of 4.6kg per kW, the 1595kg GT Roadster is claimed to hit 100km/h from standstill in 4.0sec flat and run to a top speed of 302km/h. With 4.0kg per kW, the more powerful 1660kg GT C Roadster is claimed to outrun the GT S Coupe to the tune of 0.1sec and 3mph with an official 0-100km/h time of 3.7sec and 316km/h top speed.
 
Corresponding fuel consumption is put at 9.4L/100km and 11.4L/100km for official CO2 emission ratings of 219g/km and 259g/km respectively.
 
AMG says the 65kg weight difference between the GT Roadster and GT C Roadster due to the latter receiving a higher level of standard features. Included is the rear-wheel steering system first unveiled on the GT R. It steers the rear wheels in the opposite direction to those up front at speeds up to 100km/h to enhance agility and reduce the amount of steering input that is required to turn into corners. Once the speed exceeds 100km/h, the rear wheels then turn in the same direction as those at the front in a move that is claimed to enhance longitudinal stability without any reduction in overall steering response.
 
As with the GT Coupe, the two GT Roadster models feature differing suspension set-ups. The standard GT Roadster model receives a so-called sports suspension with fixed rate damping, with the GT C Roadster boasting AMG Ride Control with adaptive damping.
 
Although Mercedes-AMG refuses to comment, German dealer sources confirm the altered styling, more powerful engine and altered gearbox ratios of the GT Roadster models will feature in the facelifted version of the GT Coupe planned for sale in 2017.

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