Mercedes-AMG GLC 63 S Coupe 2019 review

The difference now is that the transmission is linked to AMG Dynamics software that not only offers the normal Comfort, Sport, Sport+ and (on the S) Race driving modes but also a new Slippery setting for, well, slippery conditions, such as snow. Within these modes are separate Basic (Comfort and Slippery), Advanced (Sport), Pro (Sport+) and Master (Race) programmes that run in the background, effectively trimming back the interaction of the stability control and delivering a more aggressive torque split as you click through each driving mode. Confused? You should be.

Happily, the engine has been left well alone, which means you get the same 4.0-litre V8 as before. Effectively hand-built, the twin-turbocharged 'hot-vee' is a corker and in the 63 S develops a not inconsiderable 503bhp and a thumping 553lb ft at just 1750rpm. The 63 S also benefits from adaptive engine mounts that stiffen in the sportier driving modes for greater steering precision – or so Mercedes says.

And if the numbers don’t shout loudly enough for you, there’s an optional performance exhaust that’s borderline antisocial - although a near-two-tonne SUV with north of 500bhp isn’t necessarily going to win you many friends, even with the marginally less verbose standard exhaust.

Still, there are smiles to be had, and that’s largely down to the engine. This twin-turbo V8 really is a force of nature, with Mercedes claiming a totally believable and extremely rapid 3.8sec for the 0-62mph sprint. Yet it’s the instant, relentless muscle that hooks you, the car firing you out of each corner on an effortless wave of elastic torque. There’s so much twist from so little revs that you’d swear there's a massive electric motor hidden under the hood.

Apart from the noise, that is. Naturally, our car was fitted with the optional performance exhaust, which allows you to open bypass valves at the touch of a button for the full bellowing, crackling, popping and banging mechanical orchestra. It’s not a subtle way to travel, and it’s neither big nor clever, but you can’t help giggling every time the V8 clears its throat and shouts its way around to the redline.

It's therefore a bit of a shame the nine-speed auto isn’t as good. It’s smooth and swift enough when left to its own devices in Comfort mode, but it can get a bit hyperactive in Sport and Sport+, with even gentle throttle applications triggering a few unnecessary and jerky downshifts. Using the paddles helps, but even then the gearbox can get wrongfooted, with part-throttle upshifts often being sent home with a jarring thud. It can also be truculent if you leave it a little too late to upshift, causing the engine to headbutt the rev-limiter and delaying the next gearchange, which can be very frustrating.

Wind everything back to Comfort and on our admittedly well-surfaced German test route, the 63 S is on the whole impressive, its air springs dealing with long bumps and undulations with a welcome waftiness. Only sharp ridges and deeper potholes get it ruffled as it struggles to contain the quick movements of those hefty 20in wheels, while an underlying firmness suggests the car might not be so comfortable on poorly surfaced UK roads. At least, like all other GLCs, it benefits from decent suppression of wind noise, even at the naughtier end of the autobahn speed spectrum.

Another highlight is the overhauled interior. The new MBUX infotainment system has been well integrated, as has the 12.3in instrument cluster, with both helping to lift the interior to create an even classier ambience. And while the ‘Hey Mercedes’ voice control seems a bit gimmicky, it works surprisingly well, as do the augmented reality sat-nav directions that are overlaid onto the front camera view as you approach a junction. Very neat.