Driven: Mercedes-AMG GLC 63 S 4Matic+ Coupé 2017

Next time anyone asks you what Mercedes’ most powerful mid-sized SUV might be, here’s the answer: the AMG GLC S 63. Slotting into the range above the Mercedes-AMG GLC 43, it’s up against the Porsche Macan Turbo and BMW X3 M40i right now, and rivals from Jaguar and Alfa Romeo in 2018.

The GLC 63 comes in two body choices, coupé or five-door, and two performance flavours, the sportier S adding £6750 to the price. All versions have the AMG E 63’s 9-speed automatic transmission and its 4Matic four-wheel-drive system with an electro-mechanically controlled clutch connecting the permanently-driven back axle with the front one.

Suspension is four-link front (from the C 63) and multilink rear (from the E 63), with an AMG-fettled Air Body Control system providing Comfort, Sport and Sport Plus damping stiffnesses. Mercedes’ four-mode Dynamic Select system offers a wide selection of suspension firmness, steering sharpness, gearchanging speed and noise, with an extra Race mode only available in GLC 63 S models. The Eco mode incorporates an engine-off coasting function on light throttle loads between 37mph and 100mph.

GLC 63 S versions also get 20in alloys rather than the standard 19in AMG ten-spokers, plus AMG performance seats and an electronic rather than mechanical rear-axle differential lock.

All manner of optional goodies are in the catalogue, of course, including high-performance ceramic brakes at £4285 and a £1000 AMG performance exhaust. A £2755 Driver's Package, meanwhile lifts the GLC 63 Coupé’s top speed restriction of 155mph to 167mph. The S gets that kit as a default and runs to 174mph.

We tried the Mercedes-AMG GLC 63 S Coupé. Start it up in Comfort mode and it could be any large-engined SUV, but things change rapidly when Sport Plus is selected and the optional sports exhaust gains full voice. Old-school V8 thunder is complemented by a vicious bark and crackle when the throttle is released – and the performance makes a mockery of the GLC’s 2-tonne weight.

The S version has 503bhp and 516lb ft (34bhp and 37lb ft up on the regular car), enough for a 0-62mph time of just 3.8sec. A Performance Package-equipped Porsche Macan Turbo needs 4.4sec for that, BMW’s X3 M40i 4.8sec. Tread hard on the Merc’s loud pedal and the Coupé digs in at the back and hares off at a bonkers rate.

Cornering is just as impressive thanks to iron body control in Sport and Sport Plus driving modes. Even Comfort mode is pretty tidy, the air suspension keeping roll down and ride comfort sensible, and the four-wheel-drive system dishing up oodles of grip. The variable steering is precise enough, but the podgy steering wheel doesn't gift drivers with the same sense of road attachment as the Macan Turbo, and the shockingly bad rearward vision teams up with the beastily-flared out body styling to add a new level of intimidation to city driving.

Is that half-second 0-62mph advantage over the cheaper Macan Turbo important? Maybe it is if you’re playing top trumps in a football club car park. Whether you’d want to pay a £2500 premium for the coupé over the five-door GLC 63 (which has more space for passengers and cargo) will be down to your prioritisation of style over substance. Neither variant stints on luxury, quality and comfort, or on the amount of kit. Nothing is missed out in terms of connectivity and driver aids.

The near-ludicrous nature of the performance that’s on tap in such a huge machine never gets old. That, and the retention of a thumping petrol V8 in a landscape of smaller six-cylinder options, makes the GLC 63 Coupé worthy of somewhat more than just a passing look.

Mercedes-AMG GLC 63 S 4Matic+ Coupé