2018 Mercedes-AMG GT R - Glance and Aerodynamics Review (Beast of the Green Hell) REVIEW
Channel: Premium Cars
Date: 2018-01-02

There is understeer. There is oversteer. And then there's a four-wheel slide through an unavoidable spackle of rubber marbles that have built up through a fast, prolonged sweeper. A highlight reel of every other Indy 500 crash zips through my brain, as driver after driver goes off line, catches the marbles, and sails into the crunchy confines of the Safer Barrier.  But then, there is an awful lot to be said for downforce. For, even as its otherwise sticky Michelin Pilot Sport Cup 2 tires struggle with the marbles, the 2018 Mercedes-AMG GT R continues to tenaciously hold itself to Portugal's Autodromo Internacional do Algarve. The GT R isn't just an extra stein of power poured into the regular GT with some bigger, pricier brakes thrown on for good measure. That was largely the AMG M.O. of yesteryear. And, okay, it still has those, but with the R, you get extra vents, foils, ducts, and diffusers that all contribute to keeping the ultimate AMG GT adhered to Portugal through that grand corner. And, quite ideally, most of them are hidden away, preventing one of the most beautiful cars in the world from becoming an overwrought track-day special.  

Those parts also provide plenty of faith to progressively feed in throttle as that long, final sweeper unwinds into Algarve's main straight as marbles kicked up from the car ahead pang, pang, pang off the GT R's long, long hood. The lateral G's first press me into the prominent bolsters of the optional AMG race seats and then into their thin backs. It's invigorating, but then comes the deep, guttural, nasty bellow of the hand-built 4.0-liter V8 massaged up to 585 horsepower courtesy new turbochargers with a higher boost pressure, plus a modified compression ratio, sharpened throttle mapping, and a modified exhaust (including an additional, center-mount port). Mercedes says the entire combustion process has been retuned and the grand total is 82 more horsepower than in the AMG GT S.    Yet, the resulting acceleration advantage isn't just a matter of extra power (the 0–60 run is estimated at 3.5 seconds versus 3.7 of the GT S). Few areas of the GT R have avoided the weightsaver's scalpel. This includes the wider front fenders, roof, torque tube, drive shaft, and multiple structural braces made of carbon fiber, plus forged wheels and composite materials taking the place of several metal parts. Mercedes had most of these components on hand at Algarve to let us hoist them ourselves, and the weight difference is obvious – lifting the nine-pound driveshaft makes you look like The Rock – and it's easy to see how all of it together shaves off about 200 pounds versus the GT S's curb weight. 

 A further 37 pounds can be cut by opting for the carbon-ceramic disc brakes, which provide fade-free, mammoth stopping power as the main straight dips downhill before leading into a sharp right turn. They are the definition of confidence-inspiring despite the very-Mercedes low-effort pedal that makes for perfectly pleasant real-world driving.  Really, though, it's the gentlemen in lab coats manning the wind machine that have made the biggest difference. It all begins up front. Those 15 chrome slats that boldly differentiate the R from its GT siblings and evoke the original 1950s SL race cars actually disguise the fact the grille has been tilted forward for improved aerodynamics. Beneath it is the "active air management system," or a wide box filled with vertical slats. They automatically open when additional cooling is needed, but mostly stay closed to reduce drag and direct air down under the car to the next bit of engineering wizardry: the exclusive new active aerodynamics profile.    

When the car is in Race mode at speeds higher than 50 mph, a carbon-fiber blade lowers by 1.6 inches and significantly changes airflow. This reduces front-axle lift by essentially sucking the car to the ground and leads to improved high-speed steering and stability. There wasn't a GT S on hand to compare to this improved bit, but there certainly is never a reduction in confidence from the GT R's steering, which lets you sharply and fluidly turn into corners. But more on that shortly.  As the air moves under the GT R, it's channeled to the special rear diffuser or up to the air outlet between the taillights (shared with the one-rung-lower GT C).