We knew this was coming. The Mercedes-AMG GT Roadster will drop its top at the Paris Motor Show later this month, with two models launching simultaneously. The AMG GT Roadster builds upon the base version of the hardtop model, adding a bit more power and a few new features. But it's the AMG GT C that'll really grab your attention – it features a more powerful version of the biturbocharged V8 engine, and brings with it some trick features from the super-hardcore AMG GT R. Suffice it to say, the AMG GT Roadster is more than just a topless version of its coupe counterpart.
Both GT and GT C models use AMG's outstanding 4.0-liter biturbo V8. In the GT Roadster, 469 horsepower and 465 pound-feet of torque are available – increases of 13 hp and 22 lb-ft over the GT Coupe. That's not a huge bump, sure, but it means the roadster can run to 60 miles per hour in the same 3.9 seconds of its hardtop sibling. The GT C, on the other hand, brings 550 hp and 502 lb-ft to the table – that's 47 hp and 23 lb-ft more than the GT S Coupe, delivering the same 3.7-second 0-60 time. This slots the GT C Roadster right in between the S and R coupes, and as we learned from an earlier product chart, a GT C version of the hardtop is coming at some point in 2017.
The GT C uses the active rear-wheel steering system from the GT R, and the rear fenders are more than two inches wider, to account for the increased track and larger wheels.
Mercedes remapped the seven-speed dual-clutch Speedshift transmission for the more powerful tune of the GT C. First gear now has a higher ratio, while seventh gear and the final drive have lower ratios. The GT C also comes with Merc's AMG Performance Exhaust system, which we're sure sounds freaking awesome. What's more, the GT C uses the active rear-wheel steering system from the GT R, and the rear fenders are more than two inches wider, to account for the wider track and larger wheels.
It's unclear exactly how much weight the soft top mechanism adds to the GT's body, but Mercedes stresses that the three-layer fabric top is supported by a lightweight structure, combining magnesium, steel, and aluminum. The top comes in three colors (beige, black, and red), and can be operated at speeds up to 31 mph. Both versions of the roadster will get the active air management system from the GT R, with vertical louvers behind the front fascia that remain closed at lower speeds to reduce drag, but open during more spirited driving to direct airflow to the heat exchangers.
Pricing will be confirmed closer to the convertibles' arrival at U.S. dealers in about a year from now – "fall 2017," says Mercedes. Look for both versions to debut under the lights of the Paris Motor Show in late September.
Gallery: 2018 Mercedes-AMG GT Roadster
Open-top driving performance
Mercedes-AMG is blowing even more fresh air into the AMG GT family. Shortly after the world premiere of the AMG GT R, AMG is presenting two exciting roadster variants of the two-seater sports car. Alongside the AMG GT Roadster, the AMG GT C Roadster enhances the portfolio with a completely new model variant. With an output of 550 hp and peak torque of 502 lb-ft, the AMG GT C is the most powerful new Roadster variant and uses some of the technical refinements of the AMG GT R. These include active rear axle steering and the electronically controlled rear axle locking differential. In combination with AMG RIDE CONTROL sport suspension, the AMG GT C Roadster guarantees dynamic performance at the very highest level. The AMG GT C Roadster also takes its lead from the top AMG GT R sports car where muscular proportions are concerned: the wider rear fenders create space for a wider track and wider wheels at the rear axle, allowing for excellent traction and even higher cornering speeds. The variable performance exhaust system also ensures an authentic V8 sound from the AMG Roadster.
The new Roadsters make hallmark AMG driving performance an even more intensive experience. "With our two Roadster models, we are strategically expanding the AMG GT family by two exciting variants. With the AMG GT C Roadster, we are also introducing a new model variant to which we have transferred main performance-related components from our top sports car, the AMG GT R. The result: a highly dynamic driving experience in a very exclusive ambience, coupled with that pure roadster feeling," says Tobias Moers, Chairman of Mercedes-AMG GmbH.
With the two Roadster variants the Mercedes-AMG GT family has now increased to five members. The two new sports cars with fabric soft tops likewise have the technical genes for which AMG is famous. These include a lightweight and torsionally rigid aluminum bodyshell plus powerful and efficient V8 biturbo engines. The entry level into the Roadster world is the AMG GT with an output of 469 hp.
The AMG GT C Roadster adds a completely new output level. With 550 hp it is the more powerful of the two new open-top sports cars. The AMG GT C Roadster not only delivers more output and torque, it also impresses with numerous technical highlights from the Mercedes-AMG GT R for even more dynamic performance. Like the AMG GT R, the AMG GT C Roadster is recognizable by its wide, muscular rear end and large wheels. Other technical measures include the wider rear track and active rear axle steering.
The AMG GT C Roadster is also equipped with a lithium-ion battery and has more exclusive appointments. Standard features include a Nappa leather interior, AMG Performance steering wheel in Nappa leather/DINAMICA microfiber and the additional transmission mode “RACE.”
Fully automatic: the weight-optimized fabric soft top
Both Roadsters are quickly transformed from coupes to open-top sports cars. The fabric roof opens and closes in around eleven seconds, and can do this at speeds of up to 31 mph. The three soft top colors (black, red and beige) can be chosen to suit the eleven exterior and ten interior colors. The three-layered fabric soft top is supported by a lightweight magnesium/steel/aluminum structure which helps to keep the center of gravity low. Additional rollover protection is provided by an integrated aluminum cross-member with rollover bars.
New output level: the handcrafted AMG 4.0L V8 biturbo engine
With the AMG GT C Roadster, Mercedes-AMG is introducing a further output level of the handcrafted 4.0L V8 biturbo engine, thereby underlining the exclusive character of the new model. At 550 hp, the peak output is 47 hp above that of the AMG GT S and 27 hp below the Mercedes-AMG GT R. The maximum torque of 502 lb-ft is available from 1,900 to 5,750 rpm. A sprint from zero to 60 mph is achieved in 3.7 seconds, accelerating on to a top speed of 196 mph.
The AMG GT Roadster has an output of 469 hp and 465 lb-ft of torque. This variant accelerates to 60 mph in 3.9 seconds and to a top speed of 188 mph.
The eight-cylinder engine thrills with its immediate response, a linear, finely controllable power delivery and powerful acceleration in all rpm ranges. The handcrafted AMG 4.0L V8 biturbo engine comes with well-proven twin turbocharging, with the two turbochargers not located outside on the cylinder banks, but rather between them in the V of the cylinders. The advantages of the "hot inner V" configuration include a compact engine design, spontaneous response from the turbochargers and low exhaust emissions thanks to optimum air flow for the close-coupled catalytic converters.
Also adapted: the dual-clutch transmission
The developers have also adapted the seven-speed dual clutch transmission in a transaxle arrangement at the rear axle to the new power level of the Mercedes- AMG GT C Roadster by modifying the hardware and software. The first gear of the AMG SPEEDSHIFT® DCT 7-speed sport transmission 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 driver is able to set the AMG GT Roadster to his/her individual requirements using the AMG DYNAMIC SELECT controller. The three transmission modes "C" (Comfort), "S" (Sport), "S+" (Sport Plus) and the individually programmable setup "I" (Individual) allow a broad range of driving experiences from comfortable to very sporty.
The transmission mode "RACE" is additionally available for the Mercedes-AMG GT C Roadster. This mode optimally adjusts the shift strategy of the dual clutch transmission to the needs of the racetrack – very fast shift speeds and highly emotional engine sound are included. By pressing the separate "M" button in the center console, the driver can activate the manual transmission mode.
Pure sound: the AMG Performance Exhaust System
The AMG GT C Roadster is equipped with the AMG Performance Exhaust System as standard to obtain an even more emotional sound experience. Two variably adjustable flaps modulate the exhaust note of the Mercedes-AMG GT C Roadster authentically and directly. The flaps open and close depending on the selected AMG DRIVE SELECT mode, although they can also be controlled individually using a separate button in the AMG DRIVE UNIT. In the "Comfort" and "Sport" settings, the low-frequency sound typical of a V8 is designed for comfort. In "Sport+” and "RACE" modes the sound composition is far more emotional. The variable AMG Performance Exhaust System is also available as an option for the Mercedes-AMG GT Roadster.
Also for the Roadster models: active air management system from the AMG GT R
The two AMG Roadster variants have adopted a special technical highlight from the AMG GT R: the active air management system. Vertical louvers 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. Always achieving the optimum position requires highly intelligent and fast control.
During normal driving with no increased cooling requirement, the louvers are closed to reduce aerodynamic drag and specifically conduct the air to the underbody. Only when certain components reach predefined temperatures and the air requirement is particularly high do the louvers open to allow the maximum cooling airflow to the heat exchangers.
Highly expressive: athletic exterior design
From the expressive AMG Panamericana grille to the long, muscular hood and the wide rear end, the two-seater guarantees a pure sports car experience even when stationary. The striking AMG Panamericana grille underlines the motor racing heritage: 15 chrome-plated, vertical bars echo the look of the current Mercedes- AMG GT3 customer sports racing car. The new front bumper emphasizes the car's width and gives it an athletic appearance on the road. Large outer air inlets ensure the supply of cooling air to the engine and the pronounced shoulder line is suggestive of a tensed muscle, enhancing the impression of sheer power and athleticism in combination with the new 19-inch and 20-inch AMG light-alloy wheels in a 5-twin-spoke design.
Muscular with an emphasis on width: the rear end
The rear end also features numerous, conspicuous innovations. The new aluminum fenders of the AMG GT C Roadster widen the open-top two-seater by 2.25-inches compared to the AMG GT Roadster, making it the same width as the AMG GT R. Compared to the AMG GT Roadster the muscular form also creates space for larger wheels and a wider track. Both measures make for traction while allowing higher cornering speeds. The likewise wider contours at the AMG GT C Roadster's rear bumper improve airflow at the rear with large outer air vents. Both Roadster variants feature a rear spoiler integrated into the trunk lid which can be electrically extended and retracted at defined speeds, depending on the selected transmission mode.
Greater rigidity and low weight: Intelligent material mix
Mercedes-AMG also uses an intelligent material mix for the body structure of the AMG GT and GT C Roadster. Various aluminum alloys are used for the chassis and body and magnesium is used for the front deck. This extremely light element at the front reduces the inertia ahead of the front axle, thus improving agility.
The already rigid bodyshell structure has been specifically reinforced further to take account of the car's design as a roadster: side skirts with greater wall thicknesses 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. A cross-member behind the seats supports the fixed roll-over protection system.
The trunk lid is particularly light, thanks to an innovative composite material. The load-bearing structure is of SMC (Sheet Molding Compound) with carbon fiber. These high-tech plastics excel with their light weight, great strength and first-class surface condition. These innovative materials were developed by the Mercedes- Benz TEC factory in Sindelfingen and brought to production maturity together with the AMG specialists in Affalterbach. This material combination is used for the first time in the new AMG Roadsters.
The AMG lightweight construction experts have also used a composite material for the wheel-catching struts. 50 percent lighter than the equivalent in steel, these composite components help to guide the front wheels onto the side members as part of the intended crash kinematics in an accident, and to hold them there.
Derived from motorsport: the AMG Sport Suspension
The AMG Sport Suspension likewise confirms the motor racing heritage of the new AMG Roadsters. Wishbones, steering knuckles and hub carriers on the front and rear axle are manufactured entirely out of forged aluminum to reduce the unsprung mass. The wheels are also guided by double wishbones. The resulting precision in camber and track allows high cornering speeds and gives the driver optimum, highly precise road feedback right up to the very high cornering limits.
In the Mercedes-AMG GT C Roadster, the sport suspension is combined with AMG RIDE CONTROL continuously variable, adaptive damping system. The system is electronically controlled and automatically adapts the damping on each wheel to the current handling situation, speed and road conditions.
Even more agility: active rear axle steering from the AMG GT R
As standard, the new Mercedes-AMG GT C Roadster responds even more sensitively thanks to the active rear axle steering that had its debut in the Mercedes-AMG GT R. The system offers an ideal combination of agility and stability - handling characteristics that are normally in direct conflict.
Up to a speed of 62 mph, the rear wheels are turned in the opposite direction to the front wheels, resulting in significantly higher agility and increased driving pleasure with less steering input. In day-to-day driving the driver also benefits from a reduced turning circle.
Once the speed of the AMG GT C Roadster exceeds 62 mph, the system turns the rear wheels in the same direction as the front wheels, this noticeably improves handling stability. At the same time, the lateral force on the rear wheels builds up considerably faster when changing direction, which makes the response to steering inputs quicker. The driver also notices the high grip and stability of the Mercedes- AMG GT C Roadster during rapid changes of direction, without the usual tendency for the rear to break out.
On board as standard: the rear-axle locking differential
As standard the AMG GT C Roadster is equipped with an electronically controlled locking differential at the rear axle (The Mercedes-AMG GT Roadster comes with a mechanical locking differential), which is integrated into the compact transmission housing. Its sensitive and rapid control elevates the physical handling limits to a new level. It not only further improves the grip of the driven wheels, but also increases cornering speeds at the limit.
High quality and exclusivity: the interior
The interior design echoes the design lines of the exterior. The dashboard places an extreme emphasis on width, creating an impression of a powerful wing. High beltlines, concave door panels, dynamically rising center console and low seat position perfectly integrate the driver into the cockpit. The new, light-colored interior in Macchiato Beige Exclusive Nappa leather is available for the first time, lending the open-top sports car even more individuality and exclusivity.
More lateral support and comfort: AMG Performance seats
The optionally available AMG Performance seats provide even more lateral support with more heavily contoured backrest and seat cushion side bolsters. For the first time the AMG performance seat is also optionally available with the AIRSCARF® neck-level heating system, which makes open-air driving enjoyable even when the outside temperature is low. The air vent is seamlessly integrated into the seat's head restraint area. To meet the individual preferences of customers, the temperature of the warm airflow can be set in three stages.
Customers wishing to enjoy comfortable temperatures even on very hot summer days will also opt for seat climate control, which is also available exclusively for the AMG Performance seat for the first time. The intensity of the cooling can also be set in three stages.
Impressive sound in the interior: Externed Coupled Subwoofer
The Burmester® Sound System and Burmester® High-End Sound System ensure a very special musical experience in the AMG GT Roadster. Both systems benefit from an innovation developed jointly by AMG and Burmester®: the Externed Coupled Subwoofer (ECS). This new bass sound reproduction system with an extremely low bass range turns the open two-seater into a mobile concert stage.
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, transmitting the impressive sound.
The Mercedes-AMG GT Roadster and Mercedes-AMG GT C Roadster will arrive in US dealers by fall of 2017.