Mercedes GLC 53 review – six-cylinders return to rival BMW’s X3

Mercedes-AMG has just revealed its new flagship model in the form of the all-electric GT four-door, and it’s safe to say it hasn’t been received awfully well. A dedicated EV from a brand known for its engines is always going to be a hard pill to swallow for purists, but thankfully, it hasn’t ditched combustion power just yet. In fact, the new GLC53 I’m driving here gets more cylinders than the car it replaces.

While AMG turned to 2-litre four-cylinder power for a period, it’s now ditching that unit entirely in place of a 3-litre straight six. The GLC53 effectively replaces the GLC43 and GLC63, for now, and on first impressions, it looks very much like the latter. This is very clearly an AMG product at first glance, with that aggressive Panamericana-style grille, widened arches and stout AMG-specific wheels. I get behind the wheel in Germany to find out if it drives with as much purpose.

> The new Mercedes-AMG GT 4-door is a 1153bhp answer to the Porsche Taycan

Engine, gearbox and technical highlights

The engine at the core of this update is the new 3-litre twin-turbocharged M256 Evo straight-six, and while it is paired to a mild-hybrid system, the engine itself has seen plenty of attention. There’s a new cylinder head, new intake camshaft, a fresh intercooler for better thermal management and even a large intake system to give it more room to breathe – AMG says the result is better response and torque output, but more on that later.

Power output comes to 443bhp and 443lb ft of torque (472lb ft temporarily on overboost), and while that figure is technically quite some way down on the 670bhp GLC63 S E Performance, it’s only 26bhp down on the £142,200 V8-powered GT55. The 0-62mph sprint comes in 4.2sec (a time to match the CLK63 Black Series, for reference) and top speed stands at 168mph should you option the AMG Driver’s Package.

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Improved response is also said to come from the use of electrically assisted turbochargers, helping them spool up quicker than with the flow of exhaust gases alone. Combine this with the hybrid assist from the starter generator integrated within the transmission bell housing, capable of filling gaps in torque the engine can’t quite fill, and you have yourself a much more responsive engine, in theory.

A nine-speed automatic is the transmission of choice, paired to a rear-biased all-wheel drive system that engages the front axle only when it’s required. We’re not sure many owners will ever select it, but there’s even now a dedicated drift mode to make it rear-wheel drive only, utilising its limited-slip differential for more accessible oversteer… in a family SUV. 

Performance, ride and handling

A performance SUV isn’t where our hearts lie, but this car gives us a glimpse into the future of other AMG products like the incoming C53. Like the GLC, it’s set to replace the 43 and 63 S E Performance with the exact same six-cylinder powertrain, so this car offers our first look at what’s to come from AMG’s next performance saloon.

First impressions are good, as unlike many cars of this kind in 2026, the engine makes noise from the moment you press the start/stop button. An optional valved AMG ‘Real Performance Sound’ exhaust increases volume and while I prefer the silky, rich tones of the Audi SQ5’s V6 in a car of this form factor, the sound of a six-cylinder of any kind isn’t something to take for granted. Snaps on upshifts and crackles on overrun won’t be for some, though.

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This sound isn’t just for show, as the GLC 53 is quick. Much quicker than both the BMW X3 M50 and Audi SQ5 it rivals. From a standstill it launches hard off the line, revving cleanly right to the redline and with minimal interruption thanks to sharp, satisfying upshifts from its nine-speed auto – they’re quick enough for you to want to use the cold-touch shift paddles too, which isn’t a given. Downshifts are reasonable, but occasionally slur home with less conviction than you might want, with a sense that it’s reluctant to rev match aggressively. Spin the steering wheel-mounted drive mode dial to Sport or Sport+ and engine response is just as good as Mercedes claims, with a tip of the pedal giving you an immediate nudge of acceleration.  

Spin the dial back to comfort and it all settled down, easing the throttle response back, leaning into the chosen gear to make the most of that 443lb ft torque figure and softening its standard AMG Ride Control suspension… a tad. Even on Germany’s smooth, well-paved roads, ride is undoubtedly firm even in its softest mode, with secondary ride brittle over expansion joints and smaller imperfections. The steel springs make for reasonable composure and minimal body roll at higher speeds for a car of this size though, which isn’t an easy task with 2137kg to manage. Thankfully the 390mm front, 360mm rear brakes are up to the task, inspiring confidence with good modulation.

Steering is not its strong point as while it’s responsive off-centre, it doesn’t communicate much of anything at all through your fingertips. There’s an immediate sense of artificial heft to the rack, almost as if all of its components are suspended in a light treacle. Neither the BMW X3 M50 or Audi SQ5 have feelsome steering, but weighting is more pleasant in both. Rear-wheel steering as standard with 2.5 degrees of lock is nice to have, though.

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Interior and tech

It’s business as usual inside for an AMG in 2026, with those twin rotary dials on the steering wheel, a dedicated driver’s digital dashboard and a vertical central infotainment display in the centre in-line with the C-class and standard GLC. This system has all of the features you might expect, but accessing them can be just as frustrating as in any other Mercedes production, with menu systems requiring some time to fully understand.

Interior quality is reasonable, but the Audi SQ5 stands above it in this department with more premium materials and better overall build quality. The seats aren’t anything special to look at and could offer more lower lateral support for my liking, but they do the job well for a car that is unlikely to be driven hard often.

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Price, specs and rivals

The new Mercedes-AMG GLC 53 starts from £79,250, rising to £92,250 for the 'Edition 53' to give you more kit as standard – stack it up against its key rivals, the Audi SQ5 and BMW X3 M50 and it performs quite well. The Audi starts from a lower £72,905 and while it’s a solid, well-built fast SUV, its 362bhp output puts it quite some way behind the AMG. BMW’s 3-litre straight-six X3 M50 is similarly priced at £73,795, but it too falls behind the Mercedes with an output of 393bhp. 

Mercedes-AMG GLC 53 SUV specs

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