The entire point of our Lightning Lap track test is to gather the fastest lap time possible for each participating car. In the case of Mercedes-AMG’s wicked new GT R, an unabashedly track-focused coupe, we landed on the quickest lap time of all the cars we gathered at Virginia International Raceway this year. At 2:43.4, the GT R has been beaten around the grueling 4.1-mile course only by Lexus’s RC F GT concept—essentially a race car—and Porsche’s million-dollar 918 Spyder, and even then only by mere tenths of a second. Curious what vaults the GT R into this company and far, far above the regular Mercedes-AMG GT? Swipe right!
Powered by More Power
As you’d expect, AMG gives the GT R a power boost over the less powerful GT S. The coupe’s twin-turbocharged 4.0-liter V-8 engine is shared—at least on a basic level—with other AMG GT models, but here it makes 577 horsepower and 516 lb-ft of torque. That’s a 62-hp, 22-lb-ft increase over the 2018 GT S.
More Turbo!
The GT R’s dual BorgWarner turbochargers are upgraded over the GT S’s units by way of larger compressor wheels and more boost. Where AMG stuffs 17.4 psi into the GT S’s turbos, the GT R is fed 19.6. Helping the 4.0-liter V-8 swallow the extra boost is a reduced compression ratio, lowered to 9.5:1 from 10.5:1, as well as higher-flow exhaust ports for the cylinder heads.
Geared Up and Ready for the Track
For the GT R, Mercedes-AMG shortens the AMG GT’s seven-speed dual-clutch automatic transmission’s final-drive ratio and seventh gear. First gear is taller, nestling its ratio closer to second.
Taking Control of Traction Control
In most cars, defeating traction control involves pressing a mundane button. Not in the GT R, where the driver can choose among nine levels of traction control (from full off to full on) via a large yellow knob smack dab in the middle of the dashboard. During this year’s Lightning Lap track test, we would change the traction-control system’s leniency on the fly, playing with the different levels of slip allowed from the rear tires to maximize our lap times.
Loud Four Ways to the Rear Diffuser
The GT R’s AMG Dynamic Performance exhaust exits primarily through two outlets clustered in a hexagonal finisher that pokes out of the center of the rear bumper. Pressing a button on the center console or unleashing the sportier drive modes opens up two additional exhaust pathways for more loudness. The two extra outlets peek out from outboard positions.
Wingin’ It
See that slot on the vertical wing mount? That allows the rear wing to be positioned at different angles of attack, enabling owners to tailor their GT R’s aerodynamic performance to their liking. The task is handled manually, with tools, much like the wing on Chevrolet’s Corvette Z06 equipped with the Z07 package.
Splittin’ It
In contrast to the fixed rear wing, the GT R’s splitter can lower itself 1.6 inches closer to Mother Earth to stabilize the front end at speed. In fact, Mercedes says that at 124 mph, there is zero lift or downforce on the front end and 110 pounds of downforce pushing on the tail.
Carbon Fiber All the Things
Both the front and rear spoilers are made from carbon fiber, as are the roof, a trio of underbody braces, and the torque tube that carries the engine’s output to the rear transaxle. Compared with the Mercedes-AMG GT S’s aluminum torque tube, the GT R’s carbon-fiber unit is 40-percent lighter.
Rear Steer!
Much like Porsche’s latest 911 GT3, the GT R has rear-wheel steering. The feature can improve stability at higher speeds and enhances agility at lower ones by steering the rear wheels opposite the fronts below 62 mph and with the fronts above that speed.
Girth, It Has It
If the GT R appears wide, that’s because it is notably wider than the already thick-looking AMG GT. AMG stretches the rear fenders 2.3 inches to wrap around the one-inch-wider wheels and tires.
Think of It as a German Corvette, Sort Of
Fun fact: The GT R’s available Michelin Pilot Sport Cup 2 tires (as opposed to its standard, slightly different Cup 2s) are the exact same size and specification as those worn by the Chevrolet Corvette Z06.
Carbon-Ceramic Brakes?
Curious how you can tell if an AMG GT R is equipped with the optional $8950 carbon-ceramic brake package? Look for the bronze-colored calipers!
Get Low!
In addition to its three-mode electronically adjustable dampers, the GT R boasts manually adjustable spring perches that can raise or lower the ride height.
. . . So
You’re much less likely to see this view of the Mercedes-AMG GT R than, say . . .
this view, or . . .
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