2025 Mercedes-AMG GT63 S E Performance Delivers Jaw-Clenching Acceleration

Fun fact: A male hippopotamus can easily weigh 5000 pounds. Though they’re typically mild-tempered, when provoked their jaws can deliver a lethal bite that is said to be the strongest of all land-dwelling creatures. As it turns out, hippos have a lot in common with the Mercedes-AMG GT63 S E Performance. Not only does this two-door hatchback tip the scales at nearly two-and-a-half tons, the top-dog E Performance PHEV powertrain delivers one powerful bite.

Sit Down. Shut Up. Hold On.

The GT63 S E Performance’s extra mass is brought on by electrifying the powertrain. Just like the pure-gasser GT63, under the hood lies a twin-turbocharged 4.0-liter V-8; here, the eight-pot is tuned to 603 horsepower and 627 pound-feet of torque and pairs to the brand’s nine-speed automatic with a wet clutch in place of the traditional torque converter. At the rear axle is an electric drive unit that consists of a motor with 201 horses and 236 pound-feet, a two-speed transmission, an electronically controlled limited-slip differential, an inverter, and a 4.8-kWh liquid-cooled lithium-ion battery pack. Besides a few mounting points, this arrangement is identical to the hardware found at the back of the C63 S E Performance. Mercedes claims the e-unit adds nearly 500 pounds to the already porky platform. By our math, that places the GT63 S E Performance right around 4800 pounds. Staggering. But what’s more astounding is the powertrain’s combined outputs of 805 horsepower and 1047 pound-feet, routed to all four wheels.

By now you’ve likely noticed the numbers don’t add up. The combined horsepower amounts to basically rounding errors. The combined torque, however, is more confusing. A long-winded explanation from Mercedes-AMG engineers—and an even more complex formula that would have Albert Einstein scratching his head—has us taking their word for it. But merging out onto Germany’s autobahn leaves no room for second-guessing. The electric motor puts out full thrust in 10-second doses before tapering off to deliver 94 horses in 60-second intervals. The acceleration is teeth-clenchingly relentless all the way to 190 mph. We have no doubt in this car’s ability to slam into its governed top speed of 199 mph. In fact, it feels like the car has an easy 220 mph in the bag, but engineering the rotating bits to work beyond 200 mph is a costly endeavor. Mercedes claims 60 mph arrives in 2.7 seconds with Race Start activated. The seats’ stitching patterns embedded in our back suggest something much quicker, maybe even a top-10 spot on our acceleration leaderboard.

Like many of you, we were a bit put off by the second-generation GT resorting to an all-wheel-drive-only platform. For those who wish to try their luck, there’s a not-so-advertised Drift mode that decouples the front axle, sending all 805 horses to the the rear tires. You (and your tire budget) have been warned.

Stop, Drop, and Roll

For being such a portly fella, the GT63 S E Performance certainly doesn’t drive like it. This speed demon skips a conventional anti-roll-bar setup and instead uses a hydraulic anti-roll control system much like the ones found in McLarens and Rivians. The corners are hydropneumatically linked to mitigate body roll, and the system tuning varies in Comfort and Sport driving modes. Slithering through the twisty hillsides of southern Germany, the anti-roll system—and the standard 2.5-degree rear-axle steering—brilliantly masks the GT63’s weight, its body staying level through faster sweeping corners and rotating through tighter switchbacks. All of these helping hands add to the curb weight, but when you’re already a little chunky, a few extra calories won’t hurt.

Though it’s hard to find any faults with the ride quality on Germany’s buttery road surfaces in any of the three suspension modes (Comfort, Sport, Race), the steering leaves us wanting a more. There’s not much feedback making its way up from the car’s Michelin Pilot Sport S5 rubber, and off-center inputs are awfully reactive, leading to frequent corrections while turning into a corner. Thankfully, the steering is slower to respond to inputs at triple-digit speeds, but there’s still an annoying learning curve to it.

Naturally, a heavy car capable of such intense velocities needs a big brake package, and the E Performance delivers the goods. Monster 16.5-inch carbon-ceramic rotors pinched by six-piston calipers live within the front wheels, while 15.0-inch units and an off-putting single-piston caliper reside out back. We can safely say that this system comes in handy when a clapped-out Opel decides it needs the autobahn’s left lane. We can also safely say that no one will enjoy the brake pedal’s varying pressure. Sometimes you push on it and it’s nice and firm, other times there’s travel to it. It’ll even move around underfoot during sustained pressure. It’s an extremely odd pedal strategy that no one in the world ever asked for.

The Upside Down

While the GT63 S E Performance’s mission is clearly eye-pain-inducing acceleration, its electric side has an air of sensibility. Surely, an estimated seven miles of electric-only driving is nothing to brag about, but it allows stealthy travel through a town or city, only to unleash exhaust-pipe hellfire on the other side. The GT63 is decidedly not quick in Electric mode, but considering 201 horsepower is responsible for pushing roughly 4800 pounds, forward momentum is adequate. With the nine-speed’s clutches open, Electric mode routes torque forward through the center differential to enable all-wheel drive. The rear gearbox executes its one-two upshift imperceptibly, but on more than one occasion the downshift arrived with an audible clunk. Its plug-in capabilities are clearly marketed for Europe’s gasoline-unfriendly city centers, but its 3.7-kWh onboard charger should replenish the battery in about two hours when connected to a 220-volt outlet. We suspect no one in the United States will actually plug in, as the V-8’s starter/generator is plenty capable of robbing Peter to pay Paul in Race mode. Four levels of regeneration are on tap too.

The GT63 S E Performance’s lavish and technology-rich interior offers plenty of space for its front passengers, and while the back seat is optional, we’d call it mandatory. There’s only enough headroom in back for small children, but the rear seat is the only way to get the folding divider that unlocks more cargo space. And that’s critical in the E Performance, as the electric drive unit’s load-floor bulge eats up five cubic feet compared to the nonhybrid GT63.

Yes, the GT63 S E Performance is a heavy car, but that’s just the way she goes these days. If horsepower—aided by the roar of a gas-fed V-8—can keep pace with weight gains, so be it. Just make sure there’s plenty of bite, which is definitely the case here. We expect pricing for this ultimate grand tourer to start in the neighborhood of $200,000 when it arrives later this year.

Source: Reviews - aranddriver.com