Lightning Lap 2017: Mercedes-AMG GT R

Lap Time: 2:43.4
Class: LL4
Base Price: $166,875
As-Tested Price: $195,875
Power and Weight: 577 hp • 3668 lb • 6.4 lb/hp
Tires: Michelin Pilot Sport Cup 2 ZP, F: P285/30ZR-19 (94Y) R: P335/25ZR-20 (99Y)

There are plenty of cars packing more than 577 horsepower on the Lightning Lap all-time leaderboard. There are some equipped with carbon-fiber body panels, torque tubes, drive­shafts, and wings. There are even cars with underbody aerodynamic trickery to manage downforce in accordance with the car’s wishes. But no car, other than the Mercedes-AMG GT R, has all those features plus a dial-in-your-own-talent, race-car–derived nine-mode traction control.

There is another car that wears the GT R’s optional Michelin Pilot Sport Cup 2 tires, though. Michelin developed this version of the Cup 2 for use on the Chevrolet Corvette Z06 with the Z07 package [see “Mercedes Steals Corvette’s Shoes”]. The traction-control system, which metes out torque to those tires, allows the driver to progressively and quickly become comfortable. Getting up to speed? Dial it back, or left, one click. Getting cocky? Dial it back another. This grants the driver the confidence to return to the throttle sooner and sooner in turns until he’s at wide-open throttle long before most apexes.

We experimented with various traction-control settings for different corners. For areas of the track with high grip, we settled on position seven. Bitch falls off-camber and many cars oversteer on exit, so we dialed two clicks to the right (for more active traction control) on the back straight, one click left after Bitch, and one more left after exiting Spiral (bringing it back to position seven). So seamless are the traction-­control interventions that, unless you’re zeroed-in on the light ring around the dial that strobes when the system activates, you’ll never know it’s working.

The GT R’s wide fenders, racy wing, and hidden moving aerodynamic elements promise grip and they deliver. You’ll swear your eyeballs stretch over the front axle under braking into Bitch. That’s where the $8950 carbon-ceramic rotors and those optional Vette tires drop anchor with 1.27 g’s of braking force. The ZL1 1LE may have nipped the GT R in the Climbing Esses (126.2 mph to the AMG’s 124.9), but the additional speed was worth just 0.1 second in that section. In Turn 1, the GT R wrings last night’s Scotch from your liver with 1.21 g’s of lateral acceleration. The steering and braking inputs require forces commensurate to the heavy jobs at hand. Pegging the lateral acceleration feels like hanging off a cliff by your ­fingertips. Short chutes between corners provide momentary relief from the full-body flex required to hold yourself in place. A qualifying-pace lap is an Olympic workout and ends with euphoric relief.

Fast corner exits are the GT R’s game. The lap data reveals that, corner after corner, the GT R gets back to wide-open throttle earlier than any of the other cars. No corner better shows this than Hog Pen, where the rear-wheel-drive GT R exits at 112.0 mph. That speed obliterates the competition, even the all-wheel-drive Porsche 911 Turbo S. AMG knows that an epic lap is all in the exit speed. This car is stuck to the track and stuck to the top of the time sheet, hammering a lap in 2:43.4, a new LL4-class record and just 0.3 second behind the quickest car we’ve ever driven here, the five-times pricier 2015 Porsche 918 Spyder.

Mercedes Steals Corvette’s Shoes

The Mercedes-AMG GT R’s standard tire is the Michelin Pilot Sport Cup 2, but that’s not the same Cup 2 our test car wore. The slightly wider shoes on this GT R were the ones that Chevrolet and Michelin developed for the 2015 Corvette Z06. Mercedes confirmed that the TPC-spec tires—meaning they meet GM’s Tire Performance Criteria—are offered from the factory. But since “Corvette tires” would look odd on an AMG window sticker, Mercedes instead calls them Extreme-Performance Sport tires, and the option is a no-cost upgrade. If the idea of having two versions of Cup 2s for a single model seems weird, that’s because it is. German manufacturers are typically more concerned than their Yankee counterparts with the wet grip of their high-perform­ance tires. For the Z06, Michelin was free to beef up dry grip, which is traditionally at odds with wet grip. The Vette team should be flattered that AMG’s heaviest hitter is available with their tires, although they probably wouldn’t like to learn that the GT R set a record for grip in Horse Shoe with 1.21 g’s, nipping the Z06 by 0.01 g.