Mercedes-AMG has harnessed its recent track success into one of its most race-inspired cars to date. We test the new GT R...

Optimal comparable lap times aside, the advantage of having an experienced racing driver such as Deon Joubert on our team is the ability to compare notes on the strengths and weaknesses of any given performance car – on public roads in our hands, and in his on the track.

It’s the track stats that are trending these days, with “official” Nürburgring Nordschleife lap times front and centre on the press releases for vehicles with even the smallest semblance of competition woven into their makeup. However many racecar genes these vehicles may carry, they are still ultimately bound by real-world considerations, including marketable levels of comfort and convenience. Now, usually the latter means our particular racing driver returns to the pits using words such as “conservative”, “untapped potential” and, usually as a consequence of the previous two, “understeer”, but not this time.

Similar to the Lamborghini Huracán Performante we've already driven, the Mercedes-AMG GT R spent the majority of its development time attacking the 73 corners of the famed Nordschleife and, like the Lamborghini, was signed-off for production with its lap-time-enhancing apparatus still attached.

Lighter, wider and more slippery than the AMG GT S that won Performance Shootout 2016, the GT R is a picture of form and function, even when not finished in signature Green Hell Magno paintwork. The extra width is courtesy of wider tracks front and rear – the nose is 46 mm broader and the rear haunches 57 mm wider than the S’ – with the former stretched round its bespoke Panamericana grille that sports a heavily modified front splitter designed to offer both maximum downforce, yet also optimal airflow. Adding to the distinct sense of purpose is a racecar-derived rear-end with an adjustable wing and a high-tech aerofoil fitted to the underbody of the GT R. This extends downwards by 40 mm as speeds increase, the resultant ground effect sucking the car to the ground and reducing lift by a claimed 40 kg at 250 km/h.

Helping the GT R to effortlessly reach these kinds of speeds is a modified version of the twin-turbocharged 4,0-litre V8 found in the S. Fitted as far back in the engine bay as possible, new turbo compressors and a smaller wastegate, together with uprated exhaust ports, a recalibrated ECU and an optimised compression ratio, have freed up an additional 55 kW. The GT R delivers 430 kW and 700 N.m via a carbon-fibre torque-tube propshaft to a transaxle transmission with a shorter final-drive ratio.

That it launches to 100 km/h only marginally quicker than the GT S (we recorded 3,77 seconds in the R) tells but a fraction of the story of the car Mercedes-AMG claims features more motorsport-derived technology than any other AMG model before it. From a low-slung bucket seat (that’s not adjustable for height), the view over the GT R’s expanse of rippled bonnet serves as a constant reminder of both this car’s significant footprint and your backside’s proximity to the rear wheels.

They are wheels wearing brilliantly capable Michelin Pilot Cup 2 tyres that, once up to optimal operating temperatures, are supremely grippy. This, along with the Dynamic Select driving-mode switch dialled to either sport, sport+ or, if you’re brave, race mode, and the continuously variable dampers left to their own devices (as opposed to locked into their firmest setting), sees the GT R willing you to be the best driver you can be.

Make no mistake: drive it quickly and you will need to be. On a public road, the GT R’s cabin is an intense environment. The ride, despite a suspension that’s well fettled and surprisingly absorbent, remains firm, and the steering is pin-sharp. Adding to the ferocity is the available torque from a mere 1 900 r/min, which makes flexing your right ankle an engrossing affair.

With virtually no turbo lag, the R is ruthless in the way it covers ground, each near-seamless gearshift announced by one of the most guttural applications of AMG’s already notoriously anti-social exhaust system. Aided by active rear-wheel steering (a first for an AMG) and superb levels of body control, the GT R is able to shift direction with a degree of agility that belies the car’s notable 1 653 kg mass.



TEST SUMMARY

The GT R asks a lot of its driver. While other cars in this league, including the legendary Porsche 911 GT3, complement more than they challenge your driving skills, the rewards offered by the most honed AMG to date lie in the levels of bravery you're prepared to explore. Despite offering three traction-control modes, including completely disabled, and a further nine stages of slip intervention, it's advisable to spend a lot of time exploring the GT R's limits before delving into this menu. Mercedes-Benz clearly knows this, too, and a dynamic driving course is part of the purchase price.

 

As a road car, the R errs on the unforgiving, but Mercedes-Benz should be applauded for developing the GT series to this apex. In Deon Joubert's hands - behind a McLaren 650S fitted with optional Corsa tyres - it was the second-fastest car we've ever track tested at Killarney.

 

*From the January 2018 issue of CAR magazine