2027 Mercedes-AMG GT55 and GT63 4-Door Coupe EVs Driven: Who Needs Gasoline?

When you activate Attack mode in the crazy-quick Porsche Taycan Turbo GT, you get 10 seconds of full power. That’s better than its Launch Control, where you only get all 1,092 horsepower for two seconds. Count ’em, two. Activate the Boost mode in the all-new, all-electric 2027 Mercedes-AMG GT55 4-Door Coupe, and the output of its three axial-flux motors increases from a healthy 557 horsepower to a full-bodied 805 hp for 55 seconds. Sure, that’s less power than the Porsche, but we should add that the GT55’s torque peaks at 1,372 lb-ft indefinitely.

Need more? Pull both shift paddles toward you (that’s how you activate Boost mode in either AMG), and the output from the even more powerful GT63 4-Door Coupe’s trio of pancake-shaped, axial-flux motors rises from 711 hp to 1,153 hp for 63 (wink, wink) seconds, while the 0-rpm torque peak remains at an inmates-running-the-asylum 1,475 lb-ft. If that strikes you as a ton of torque, you’re not wrong. And those numbers aren’t even the craziest part about these two new AMGs.

No, the real crazy part is that when you reach the end of your allotted boost time, you can just pull the paddles again, and you’re back making full power. In either car. And you can keep doing it over and over again. There’s no limit, unlike in the Taycan Turbo GT where you need to wait four seconds before entering Attack mode again. Don’t feel like pulling the AMG paddles every 55/63 seconds? Rotate the round dial on the lower righthand side of the steering wheel clockwise three times, and you’ll be in Race mode, which gives you full power until its fancy new battery is dead. I wouldn’t worry about running out of juice, though, as we did eight consecutive fast laps around a 2.7-mile-long configuration of Spain’s excellent Ascari circuit and pitted with over 60 percent of the battery left. Should you need to charge, and especially if you have the proper infrastructure, these new go-fast Mercedes-AMG GT EVs will most likely be the fastest-charging vehicles you can (soon) buy in the U.S. How? It’s mostly about the battery.

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The Tech

All manner of high-tech engineering is going on underneath the rather questionable-looking skin of the electric GTs. But the big, industry-on-notice innovation is the liquid-cooled battery pack. At a roundtable discussion, Mercedes CTO Jörg Butzer wouldn’t tell us who its technical partner is, let alone the properties of the proprietary oil that cools the battery. All we know is A) it’s nonconductive, and B) it works brilliantly. Cooling battery cells is tricky. Some automakers cool them via the top or the bottom of the pack. GM, Lucid, and Rivian, for example. Others, like Tesla and BMW M, run serpentine cooling strips between the individual cells. With these new AMGs, as well as the SUV variants like the GT63 AMG SUV that will soon follow, all 2,660 cells are fully bathed in this secret cooling sauce, allowing the batteries to charge and discharge faster and longer.

We witnessed the future of AMG’s charging firsthand. While we’re fairly certain Mercedes took down the power grid in the nearby town of Ronda to keep all the press cars charged, it also brought a 1,000-kW charger to the event. Without getting into too much techie talk, the GTs are only capable of accepting 600 kW. That said, we got a taste of how well the system takes advantage of both the oil bath and its 800-volt electrical architecture, as a GT63 went from a 17 percent SOC (state of charge) to 80 percent in 10 minutes. This is roughly twice as fast as the current state of the charging art. Mercedes told us that at least one of these mega chargers will be installed at every one of its Mercedes-Benz Charging Hubs. Should you be on a road trip and in a hurry, you can reserve said big-ass charger so that you’re back on the road ASAP. No, they didn’t have a good answer for, “What if two cars reserve the charger at the same time?”

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Among the other cool tech is the diagonally linked hydraulic dampers, negating the need for anti-roll bars (as seen on some McLarens and Rivians). Mercedes calls it AMG Active Ride Control+ and it’s optional on the GT55 (replacing the air suspension) and standard on the GT63.

The cars are all-wheel drive with torque vectoring on the rear axle (both GTs feature a single motor on the front axle and two on the rear), all-wheel steering, and the front brake rotors are carbon ceramic whereas the rears are “weight-optimized steel discs.” That last bit might seem chintzy on cars starting in the mid- to high $100K range, but since the two rear motors are also involved with braking via regen, carbon-ceramic material on the rear rotors wasn’t needed.

While the liquid-cooled battery is easily the most important part of the new AMG GT EV tech, it’s not visible. Having to explain why your car is cool is never cool. To the person on the street, the showstopper is the active aerodynamics, particularly the two rear components. From front to rear, the grille shutters are active, as are the air intakes for the front brakes. Underneath both GTs (optional on the GT55, standard on the GT63), you will find two moving elements, known as Aerokinetics Venturi Flow in AMG speak. The front underbody element deploys at 75 mph, whereas the middle section opens at 87 mph. Both use the venturi effect to generate more ground-hugging downforce.

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As mentioned, the real party starts at the rear of the vehicle, and for those of us of a certain age, nothing will ever be more thrilling than the first episode of season 4 of Knight Rider, when Kitt not only gets revenge against the evil Juggernaut, but is rebuilt with the perhaps a bit too Transformers-like Super Pursuit mode. The GT’s rear wing can rise to about a 45-degree angle. Much cooler is the rear diffuser that extends about 6 inches. Similar to the wing-things that slide out of the rear of the new Porsche Cayenne Turbo EV, the big moving part is weirdly cool. Does it need to exist? Yes, and smartly, AMG included excellent software that visually shows you how the airflow around the vehicle is affected when the various moving parts are engaged. Cool and fascinating technology.

Less cool are all the V-8 engine sounds. AMG recorded the last-generation AMG GT-R’s 4.0-liter twin-turbo V-8 (the cross-plane one, not the flat-plane version found in the GT Black Series or new gen GT two-door coupes), and if you switch into Sport+ mode, both EVs sound and vibrate pretty close to what an actual V-8-powered Mercedes is like. That said, some of the other journalists on the launch absolutely loved the fake sounds with their accompanying fake gears. More on this in a bit.

The Driver Controls

Making its debut on the electric GTs is a series of three control knobs located to the left of the cupholders called AMG Race Engineer. Before the full explanation, have you ever been driving a car with active dampers and you have to really concentrate to notice the difference between Comfort and Sport? That’s not the situation here. Really, we're not being hyperbolic (OK, maybe a little): In the history of the automobile, three controls have never had such a startling effect on a vehicle’s behavior.

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The first knob is called Response Control, and it’s fairly easy to understand. All three AMG Race Engineer controls are activated by a single push and feature nine stages of control. When you activate Response, your throttle map is essentially in the middle at 5. Twist it counterclockwise to 1, and it seems like you’re driving a slushbox automatic. Twist the other way up to 9, and you get the kind of instant electric response that people complain makes them sick in cars like the Tesla Plaid and Lucid Sapphire.

Next up is Agility Control. It’s much more difficult to understand, but basically 1 is a bunch of understeer, and 9 is crazy, butt-out oversteer. Agility doesn’t affect traction control in any way (that’s the next one), but rather you’re tuning the torque distribution of the three motors. You can obviously delay some of the oversteer by reducing the Response, but we’d need hours to lock it all down. It honestly feels weird that AMG gives you this much control over the fundamental handling nature of the chassis, but here we are. The final knob is Traction Control, and this one isn’t new. In fact, the tech made its debut on the same AMG GT-R that provided its engine sound. Activating it defaults to 5, which means traction is halfway off.

The Day-to-Day

We drove the GT55s on the street and the GT63s on the track. In terms of size, the new electric GT four-door is slightly larger than a Mercedes E-Class in terms of wheelbase, length, and width. However, even though you’re sitting on the batteries, the GT’s roof is around 2 inches lower than an E-Class. As such, you’re sitting in a spacious and comfortable cabin, though it’s a bit tight with a helmet on. The optional brown leather one of the AMG GT55s wore is lovely. The latest version of MBUX powered by the newest version of MB.OS is excellent. Moreover, the new GTs are fully software-defined vehicles, and Herr Butzer claims the cars are 99 percent OTA updatable. To reiterate, this is the best Mercedes interface we’ve ever experienced, and it bodes well for future products.

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What struck us right off the bat is how excellent the steering is. Just as good-feeling as anything. The day before, we drove the heavily refreshed Mercedes EQS Sedan with steer-by-wire and a yoke, and it was as bad as anything. Yes, Mercedes’ EVs are in the two-hands-ain’t-talking situation; here’s hoping the EQS was a prototype. Regardless, the GT55 combines sublime steering with a good amount of power. Again, 557 hp and 1,372 lb-ft of torque is enough to go buy eggs. That said, we were driving around rural Spain, and the average vehicle we encountered was packing a 1.2-liter diesel. Time to engage the Boost! Did we need all 805 hp? Of course not. Did we use it every single time without fail while passing countless slower vehicles? Every single time.

One thing: Having used various boosts and overboosts over the years, sometimes you push the push-to-pash, jump into the oncoming lane—and, oh dear, here comes a bus. So you slide back into your lane. The whole encounter takes 12 seconds to play out, and then you’re out of boost. Having 55 seconds of extra power reduces that sort of stress completely. And remember, if you come across a whole parade of buses, just activate Boost again. And again. If you want to sound and feel like a gas-powered car, flip the mode selector into Sport+, and—vroom, vroom—you got engine noises along with engine vibrations tickling your spine via the speaker in your seat back (you cannot decouple the two and nine fake gears complete with a 7,200 rpm “redline.” It’s not a real redline, obviously, and unlike the Hyundai Ioniq 5 N or refreshed 2027 Taycans, you can’t repeatedly bounce off a fake limiter. These AMGs automatically upshift. The V-8 cosplay doesn’t show up in any other modes. That said, we’ll give you one hint about the very first over-the-air update. Also: Customers can expect meaningful software updates four to six times per year.

As a street machine, the AMG GT55 4-Door Coupe is excellent. Truly hard to fault. But is an even more powerful version needed on the track?

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The Racetrack

Yes, yes, the AMG GT63 4-Door Coupe works wonders on the track. And yes, let’s ignore the part about “who pays $180K for 5,500-pound electric sedans to take on tracks?” and concentrate on how amazingly this machine rips up a racetrack. The AMG GT63 is a nearly three-ton scalpel: It’s sharp to turn in, as quick as any car post-apex, and has grip for days if not weeks and fantastic body control. We suppose it’s fun to be in Sport+ and have fake gears and pull the paddles to “shift,” but it’s not an especially useful tool for turning fast laps. Apparently, AMG doesn’t think so, either, which is why all that faux-shizz goes in away in Race mode, which, remember, gives you full power all the time.

Once we had four laps under our belts, we were invited to try out the AMG Race Engineer controls. The Mercedes team had us running in packs of three, with an instructor in a lead GT63 and two journos following behind. We were the third car and happened to be chasing none other than former MotorTrend editor-in-chief Angus MacKenzie around Ascari’s scenic, olive-tree-lined circuit. Angus and I were pretty evenly matched (he’s probably a tick or two quicker) until we put the Agility Control into 3 and Traction into 3. Suddenly, and probably because we prefer a bit of understeer when we’re driving quick, we were all over his rear bumper. We’d run the previous laps about four car lengths back, and suddenly we could make it just one. On the next lap, we turned the controls to 5 and 5, and it’s hard to state how radical that seemingly small change had on the AMG’s behavior. It felt like we were driving a different car. On the 5/5 lap, the car was an order of magnitude looser. We found the rear stepping out on throttle (remember, there’s a truckload of torque!), and we were no longer fogging Angus’ mirror. And brother, did we have to work for it.

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There’s a saying: Old age and treachery will always defeat youth and skill. Not that we have either youth or skill these days, but on the next lap we switched Stability and Traction into 7 and 7. Suddenly, our GT63 was all over the place. Coming out of tight corners, Angus was gapping us on the straights by an eighth of a mile. We couldn’t keep the damn thing pointed straight under power. With nearly everything off, the GT63 was too much for us to drive smoothly. When we were talking about it off track, we said something to Angus about how his formative rally skills are still paying off and with a knowing grin, he said, “Naw mate, I saw how loose the instructor’s car got in 7 and 7, so I just left it in 5 and 5.” Kids, this is why we respect our elders. The larger point is that AMG is opening a Pandora’s box of control that could be a problem if used in the wrong hands. Use it wisely.

We asked an AMG development engineer why. Why are they allowing such a wild spread of behavior when you’re on a racetrack? Why not just give the customers AMG’s point of view? Aside from the usual “because we can” type of stuff, he said something rather interesting. “The car comes on Michelin Pilot Sport 5s. Let’s say you want the car on [Pilot Cup] Sport 2s or 2Rs. Well, then the modes we preprogrammed will no longer work. Plus, racing surfaces vary greatly in terms of grip. We wanted to give the customer full control on the track.” Unlike the phony gears and noises, that last part makes a lot of sense. And again, what great tech.

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The Conclusion

Great cars. Both of ’em. As for the competition, you’re talking about serious, big-dog stuff like the Porsche Taycan Turbo GT with Weissach package, even the Manthey version, and Lucid Air Sapphire. Which is better? This is why we do comparison tests, so stay tuned. As for the new GTs, AMG truly went the extra mile in terms of battery tech, power, active aero, and driver customization. They should be applauded, as both the GT55 and GT63 are exceptional automobiles. Great achievements. Which one should you buy when they go on sale sometime later this year (GT63 first, then GT55 in Q1 of ’27)? Obviously, we recommend you pony up for the GT63. Power is power, after all; sometimes more really is more.