Snarling 2018 Mercedes-AMG GT R designed to head-to-head with Porsche 911 GT3 RS

We’ve got to admit – it’s a helluva green. Actually, it’s called Green Hell Magno, and it’s the signature colour of the 2018 Mercedes-AMG GT R: the hottest, fastest, loudest machine in Daimler’s rapidly growing line-up of Porsche 911-fighting sports cars.

The people at AMG have a sense of humour. They call the GT R “the Beast from the Green Hell.” And yes, in Sport+ and Race modes it roars and snarls like an angry monster when you nail the throttle. The explosions from the exhaust when you lift off suggest you’re about to be overrun by an artillery barrage. Beyond that thundering wall of sound, though, is a carefully engineered sports car that’s crushingly fast, impressively agile, and very well mannered.

Mercedes-AMG GT R is AMG’s latest weapon, which has been designed to go head to head to head with the Porsche’s 911 GT3 RS. At its heart is a handcrafted AMG 4.0L V8 bi-turbo with output of 577 hp, which is 74 hp more than the previous top-of-the-range engine in the GT S. Peak torque of 516 lb-ft is available between 1,900 and 5,500 rpm.

From behind the wheel, the AMG coupe feels a big car, much bigger than a Porsche 911. You aim the thing into corners over that long hood, the front wheels way off into the distance.

There is not quite the delicacy of feedback you get from a 911, either, and although the dual-clutch transmission is adept at serving the gear you want, when you want it, particularly in Race mode, it’s still not quite as sharply intuitive as the new 911’s PDK transmission.

The increase in performance was achieved with the help of new turbochargers with modified compressor machining, a smaller waste-gate and new engine mapping. Boost pressure supplied by the turbochargers has been increased from 17.4 psi on the AMG GT to 19.6 psi. In addition, the exhaust ports have been optimised and the compression ratio modified.

The seven-speed dual-clutch transmission has been extensively revised by AMG, with modified hardware and software to make the transmission even more suitable for the racetrack. First gear in the AMG Speedshift DCT 7-speed sports transmission has a longer ratio, while seventh gear and the final drive have shorter ratios to allow for more rapid acceleration.

Expect savage performance seeing due to the liberal use of weight-saving aluminum and carbon fibre. Mercedes estimates 0-60 in 3.5 seconds but we believe it will be quicker. The specially developed exhaust system not only delivers genuine racing car sound, it also saves around 13 lbs. of weight compared with the AMG GT S thanks to the use of titanium for the rear silencer and thin-walled stainless steel for the front section of the exhaust system.

In addition to the carbon-fibre torque tube that connects the engine and transmission, the GT R’s front fenders, roof, engine bay, and internal cross braces are all made of the weight-saving material. The prop shaft inside the torque tube is also carbon fibre. Weighing less than 9 pounds, it is about 50 percent lighter than a comparable steel shaft.

Drivers can tailor the AMG GT R to their personal preferences using the AMG Dynamic Select controller. Various modes are available: “C” (Comfort), “S” (Sport), “S+” (Sport Plus) and “I” (Individual). The “Race” mode optimally adjusts the shift strategy of the dual clutch transmission to the needs of racetrack usage – shortest 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 in any drive mode.

Conventional suspension measures include the wider front and rear track as well as the standard-fit Michelin Pilot Sport Cup 2 tyres, of size 275/35 ZR 19 at the front and 325/30 ZR 20 at the rear. The street-legal racing tyres allow faster laps and up to 50 percent more mileage on the racetrack.

The interior is also strongly inspired by motorsport. AMG Performance Seats (also equipped in the AMG GT S) are covered in Nappa leather and Dinamica microfibre come as standard. They offer good lateral support even in extreme driving maneuvers. The optional yellow seat belts, dials with yellow highlights, the AMG Black Piano Lacquer interior trim and special controls, including those for the new AMG Traction Control, underline the unique standing of the new AMG GT R.

The new AMG “Interior Night package” will also be available. In this package, the shift paddles, steering wheel bezel, door sills and trunk cross member are finished in high-gloss black, which combines with the standard-specification AMG Interior Piano Lacquer package to further emphasise sportiness. As an option, customers can order the trim in matte black carbon fibre.

Expected to arrive towards the last quarter of 2017, this green beast will be priced from around £143,000.

At a glance: Mercedes-AMG GT R Spec

Engine: Handcrafted AMG 4.0L V8 Biturbo with Dry-Sump Lubrication

Displacement: 3,982 cc

Output: 577 hp at 6,250 rpm

Peak torque: 516 lb-ft at 1,900-5,500 rpm

Driven wheels: Rear-wheel drive

Transmission: AMG SPEEDSHIFT DCT 7-speed dual-clutch transmission

Weight: 3,428 lbs (Euro spec; US spec may vary)

Power-to-weight ratio: 5.94 lb/hp (Euro spec; US spec may vary)

Acceleration 0-60 mph: 3.5 seconds (est.)

Top speed: 198 mph