Mercedes-AMG GT 63 E Performance | UK Review

Can't stretch to a Mercedes-AMG One? How about the next best thing...

By Nic Cackett / Monday, 30 June 2025 / Loading comments

Mercedes-AMG, like most carmakers, is straddling a fence. On one side, there is the past. It contains naturally aspirated V8s and clutch-melting V12s, and everyone walks around wearing Castrol GTX jackets. On the other, there is the future, with its rare earth metals and expectant conversations about solid-state batteries. Let’s imagine everyone there wears a hangdog expression. Cars like the exclusively V8-powered GT 55 we drove last month are mostly about the past now; concepts like the GT XX, stuffed to the gills with horsepower and wildly speculative charge times, are naturally about the future. But Mercedes-AMG must be about the present, too, where neither version of itself, past or future, can be relied upon to tell the whole story. Thus we have the fence.

Many of the cars that it has designed to fill out this transition period are only half good. Given the breadth of its range, this was inevitable. While it’s true that any motor vehicle built for the road is the product of multiple compromises, no other car is forced to wear its trade-offs quite so on the sleeve as the plug-in hybrid - especially when asked to be a performance model. These shortcomings have resulted in a formidable amount of technical endeavour, much of it deployed as very sophisticated sticking plaster. This is remarkable when you are reminded that PHEVs are neither the past nor the future, nor even really a bridge between the two. They are an imperfect solution to what is, comparatively speaking, a short-term problem.

The GT 63 S E Performance, with its 816hp combined output and £186,290 starting price, ought to be a case in point. Mercedes-AMG, you’ll likely recall, also sells a ‘standard’ GT 63, which develops 585hp using the same 4.0-litre V8, offers nearly twice the boot space and is 200 or so kilograms lighter than the PHEV. Not to mention £20k cheaper. Moreover, thanks to its AMG High Performance battery - notable for its diminutive 6.1kWh capacity - the E Performance is limited to a seven-mile EV range and only improves combined economy by 6.5mpg. Incredibly, the GT 55, nominally the mid-tier option, is capable of reaching 62mph in less than 4 seconds, yet has 340hp and 531lb ft of torque less than its electrified sibling. All this makes the flagship version seem less like the silver bullet Mercedes-AMG plausibly needs and more like the answer to a question no one could possibly be asking.

But Mercedes-AMG has been here before. Probably no one thought they needed an A-Class with more than 400hp or an SL with more than 600hp - or a hypercar with a 1,000hp F1 drivetrain. Outright power is a preoccupation for most prestige brands, but precious few have made it such an obvious point of pride. Or done such a fine job, generally speaking, at turning seemingly improbable peak numbers into raucously good and likeable cars. Granted, the four-cylinder C63 S E Performance was an object lesson in how 680hp could not be made to paper over a fundamental deficit of charisma and dynamic payoff. But the electrified GT 63 does not suffer the same fate. Far from it.

Fundamentally, of course, it has the V8 in its repertoire - and that’s like finding out your vegetarian meal comes with a fillet steak side dish. Except it’s not really a side dish, it’s a 612hp medium-rare main course, and very rarely will you ever take a bite of the E Performance which isn’t all about cylinder-based protein. That much was perhaps to be expected - and indeed welcome. The revelation here is that for once the 204hp and 236lb ft of e-motor-based assistance does not play sprig of broccoli to this side of beef, but more often than not seems as complementary and invigorating as a dab of horseradish.

Briefly, there are three reasons for this. First and foremost, it does its primary job - aiding throttle response - predictably well. The lag that Matt Bird noted in his review of the GT 55 is not just conspicuous for its absence, but turned on its head: the E Performance, all 2,340kg of it, ghosts away from the line like it was made from wet tissue paper. Crucially, and secondly, the assistance never outstays its welcome; it is as succinct as an assassin’s text message. And because of that and the battery’s small size (and the clever tech overseeing its recuperation), you need never plug it in to charge. Thirdly, it is clear from the outset that both V8 and rear-mounted, boot-infringing e-motor are essential to making this GT 63 as brain-meltingly fast as it is - and at 2.8 seconds to 62mph, we’re talking as fast as conventional road cars get - but also keep its astonishing appetite for forward motion from seeming overwhelming. Or outright terrifying.

Some have suggested that this is a facet of the drivetrain’s remoteness compared to petrol power alone, but I’m inclined to think it’s more about linearity and the way that the E Performance incorporates its battery-powered surge into the tsunami of turbocharged V8. Perhaps it’s simply because it ensures the GT 63 seems instantaneously fast everywhere, making everything that follows seem consistent with an unbridled, mass-defying level of acceleration. At any rate, there’s never the sense that the car is toting 1,047lb ft of torque around in something like Pandora’s Box, making its unpacking seem as perilous and potentially pant-wetting as a fire in the footwell - instead, it’s an ever-present and easy-to-modulate commodity that you dip into guiltlessly and often.

Well, I say guiltlessly. You’d do best to plead ignorance of the speedometer on quiet, open stretches of road. And not just on German-style A roads either. Perhaps there isn’t much new to say about the GT 63’s melting pot of active aero, adaptive ride control (including hydraulically interlinked dampers), rear-axle steering and carbon ceramic brakes, but for a chassis chiefly concerned with enabling the car’s performance, it does an exemplary job of making a two-metre-wide, 2.3-tonne Mercedes feel right at home on a leather-faced B road. The steering doesn’t rival the crispness nor the connection of a 911 Turbo S - but what it lacks in fingertip nuance it makes up for with processing power and the sort of ground-hugging, corner-scorning stability you’d bet your life on. Which is apt for the entry speeds it generates.

Of course, this is less interesting than the feel-good factor that accompanies it - traditionally the plug-in hybrid stumbling block. The E Performance is hardly without familiar vices: it is vastly expensive and vastly complicated, not to mention being less practical and not a whole lot kinder to the environment than the standard GT 63. Clearly, Mercedes has produced objectively more serious and well-reasoned sticking plasters. But this just confirms the new model as something else entirely - something better and infinitely more desirable. Here, at last, is a PHEV sufficiently outrageous in its output, speed, sound, look, even its contradictions - to embody old-school AMG at something like its fatuous best. Considered alongside the equally persuasive T-Hybrid 911, it is almost enough to convince you that another decade atop the fence isn’t a bad place to be.

SPECIFICATION | 2024 MERCEDES-AMG GT 63 S E PERFORMANCE

Engine: 3,982cc, V8, twin-turbo, plus permanently excited synchronous electric motor and 4.84kWh (usable) battery
Transmission: nine-speed auto, four-wheel drive
Power (hp): 816 (system output; ICE 612 plus 204hp electric motor)
Torque (lb ft): 1,047 (system output)
0-62mph: 2.8 seconds
Top speed: 199mph (limited)
Weight: 2,340kg (EU)
MPG: 26.7 (WLTP)
CO2: 241g/km
Price: £186,290 (as tested: £200,500)