With such a plethora of options now out there, it can be easy to forget that AMG pretty much pioneered the uber SUV thing back in the late 1990s with the ML55 AMG. Back then the idea of a 4×4 with a 5.4-litre V8 and almost 350hp seemed like lunacy, and now look where we are – that car is kind of a gamechanger. Perhaps the same fate will also befall the latest AMG GLCs, complete with their 2.0-litre, four-cylinder engines…

That’s right, just as with the C-Class saloon with which it shares so much, the GLC SUV has switched from 3.0-litre V6 (for the ’43) and 4.0-litre twin-turbo V8 (in the ’63 S E Performance) to a four-cylinder turbo for both, one with hybrid assistance for the flagship model. If not quite such a seismic shift as for the saloon and estate (because people don’t care about the SUV so much), it’s a pretty momentous change for the GLC.

Specs will be familiar to anyone who’s closely followed the C-Class’s reinvention. The GLC 43 is powered by a 421hp, mild hybrid version of the M139 engine found in the A45, driving through a nine-speed MCT (it’s an eight-speed DCT in the hatch) to a rear-biased all-wheel drive system. With 369lb ft as well, AMG reckons the new GLC 43 is good for 62mph in 4.8 seconds and 155mph. The 48-volt mild hybrid system improves efficiency by helping out with stop-start and coasting.

It’s the ’63 that’s undergone the most dramatic reinvention, however, adopting wholesale the new C63 powertrain. That means the M139 is boosted further to 476hp and 402lb ft, then joined by a 204hp, permanently excited synchronous electric motor and 6.1kWh battery – for 680hp in total, plus 752lb ft of ‘system torque’. The numbers are, of course, absurd: 3.5 seconds to 62mph, a 170mph limited top speed, 2,310kg and 7.5 miles of electric range. The nine-speed automatic gearbox is also fitted to the ’63, its parameters adjusted – along with much of the rest of the dynamic make-up – through eight AMG Dynamic Select drive modes (it’s five in the ’43).

Containing all that horsepower is a familiar suite of AMG chassis technology. While the ’43 gets rear-biased (31:69) 4Matic all-wheel drive, the ’63 is fitted with the fully variable 4Matic+ that allows everything up to 100 per cent rear-wheel drive. Ride Control suspension with the Adaptive Damping System is standard on both, as is rear-wheel steering, with the additional benefit of AMG-specific axles (including bespoke steering knuckles and suspension joints).

The ’63 builds on this with AMG Active Ride Control, which should keep it comfy on the straights and controlled in the corners. Both are slowed down by some burly old brakes, too: for the GLC 63 S E Performance, that means a 390mm front disc with a six-piston caliper, with 370mm rotors on the rear. AMG promises ‘very short braking distances as well as maximum stability and fade resistance under heavy use’.

As is AMG tradition, there will be an Edition 1 for the 680hp model available for the first year of sales. The GLC 63 will be offered in graphite grey magno or high-tech silver magno, with 21-inch black wheels, a standard AMG Aerodynamics Package, both AMG Exterior Night Packages and an interior dominated by black and yellow. There’s even an Edition 1 car cover thrown in. Standard models will have 19- or 20-inch wheels, plus AMG-specific grilles, front apron and diffuser, with the ’63 made to look the more aggressive of the two. The interiors get the latest MBUX infotainment and AMG trinkets, including Track Pace datalogging app for the North Circular GP.

Michael Schiebe, Mercedes-AMG CEO, added of the new models: “The Mercedes-AMG GLC SUV is an absolute success with our customers… With the E Performance drive in the GLC 63 S, we are also launching the first performance hybrid SUV. The all-wheel-drive system, the active rear-axle steering and the quick-shifting transmission enhance the emotionally appealing hallmark AMG driving experience”. We’ll have to take his word for it for now, and hope the switch to an electrified powertrain is more successful here than in the other ’63. If not, you know where to find a V8 one…