What is it?
This is the facelifted version of the fastest SUV Mercedes makes. Like all models in the GLC range, the superheated AMG 63 and 63 S have been treated to a mid-life nip and tuck, which extends to some cosmetic tweaks, upgraded infotainment and some mind-boggling driver mode additions.
Externally, the changes are subtle, with both the regular GLC and the GLC Coupé - which we're testing here - getting sleeker LED headlights, an even more prominent grille, revised tail-lights and a natty pair of trapezoidal talpipe surrounds. There are also some fresh alloy wheel designs, including an optional 21in set.
Inside, the influence of the latest A-Class is brought to bear, with the introduction of the latest MBUX infotainment and digital dial pack. There’s also Mercedes' latest steering wheel design, complete with its bewildering array of buttons and switches. Still, it looks good and feels nice in your hands.
Mechanically, the changes are small. The multi-chamber air springs and adaptive dampers are now standard on the 63 and 63 S, as is an electronically controlled limited-slip differential. Channelling power is the AMG Speedshift MCT 9G nine-speed automatic gearbox and the 4Matic+ all-wheel drive system that can send torque wherever it’s needed.
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.