► 671bhp, 0-62mph in 3.5-seconds
► Same four-pot PHEV powertrain as C 63
► Active anti-roll bars standard
Before I start, let’s deal with the elephant in the room. Like its smaller saloon shaped sibling, the (deep breath) Mercedes-AMG GLC 63 S E Performance ditches the 4.0-litre twin-turbo V8 of its predecessor. Instead, there’s a 2.0-litre four-cylinder turbo, battery pack and an electric motor.
That’s right, the GLC 63 has gone plug-in hybrid. It’s a very different system to what you’ll find in a cooking Mercedes GLC PHEV with a focus on performance rather than efficiency. The 63’s four is a development of the engine you’ll find in the A 45 megahatch, SL 43 and of course the C 63 saloon/estate.
Pros: Entertaining handling, can be exceedingly fast, reasonably practical
Cons: Variable performance, feels cheap in places, expensive
What are the specs?
With a large turbo that gets spooling assistance at low revs from an electric motor, the engine on its own is good for 470bhp, or not far off the old V8. Add a diddy 4.8kWh battery discharging into a 201bhp motor and combined output is a mighty 671bhp with a thumping 752Ib ft of torque. With launch control active, it’ll do 0-62mph in 3.5-seconds and tops out at 171mph.
Naturally all the complicated hybrid bits add rather a lot of weight, with the GLC 63 tipping the scales at a portly 2310kg. To help mitigate this in a tall SUV, all 63s get something called Active Ride Control. It essentially splits the anti-roll bars in two, with the pieces connected in the middle by an electromagnetic actuator.
The theory is that the bars remain separated in normal driving conditions improving comfort. Start loading up the chassis and the actuator twists them against each other, propping up the body.
If that wasn’t enough complication, there’s also standard four-wheel steering. At up to 62mph the rears turn up to 2.5 degrees in the opposite direction to the fronts to improve agility and the turning circle. Above this speed they turn in the same direction as the fronts, boosting stability.
How does it drive?
Starting with the good, the GLC 63 does a fantastic job of hiding its mass most of the time. Turn in to a bend regardless of speed and the rear steer helps aim the nose towards the apex effectively while the body stays startlingly flat. Only under braking do you get a few hints, with the pedal starting to get a little long and the smell of cooking brakes wafting into the cabin after some hard road driving despite composite brakes being standard fit.
Unlike some Mercedes 4WS systems, there’s a pleasing linearity to the steering rather than a noticeable ramp up in wheel angle at a certain lock. It’s weighty even in comfort mode, although thankfully Sport, Sport+ and Race modes don’t add too much additional treacle. There are even a few messages about the front tyres’ activities.
There is of course an e-LSD on the back axle that talks to the e-motor to boost traction further and reduce ESC intervention. It hooks up exceedingly well, but there is also entertainment to be had. With one of the racier drive modes selected you can feel the car rotate slightly under power, with the ESC’s Sport mode allowing a little more angle.
You won’t get big lairy drifts, but its more willing to let you have a few degrees of angle on corner exit than the old GLC 63. Given our hairpin-packed test route, this was most welcome. The only fly in the ointment here is the occasional tendency for the rear axle to hop slightly as it slides, although the GLC 63 is by no means the only hot SUV to do this.
AMG has been banging on about how this is a performance-focussed hybrid and they’re not wrong. That little battery is good for a claimed electric range of nine miles, so it still emits 170g/km of CO2 and is in the top 37% bracket for company car tax.
Even with electrification, this just isn’t a particularly efficient engine in the real world, either. While officially it’ll do 37.7mpg, with a discharged battery it’s more like 27mpg if you’re careful. After a spirited run on a particularly enjoyable mountain pass, the lowest we saw was 7mpg despite starting with a full pack. Performance is also variable, with the GLC sometimes feeling every bit as potent as the headline power figure suggests. However, the electric motor can only output 201bhp for short periods, so frequently you’ve got less than 600bhp.
While we’re on the subject of everyday usability, we have our concerns when it comes to the ride and refinement. Even on smooth Spanish roads the GLC never fully settles down, while expansion joints thud through the cabin. And while the engine settles into the background and wind noise is well contained, coarser stretches of tarmac revealed plentiful tyre roar.
What about the interior?
If you’re hoping the little battery will mean more boot space than the other GLC PHEVs, prepare to be disappointed. Although the battery is indeed smaller, the complex rear drive unit means it has the same 470-litre boot as those models, a massive 150-litres down on mild hybrid versions including the AMG GLC 43.
Space for rear passengers is good, and there’s no shortage of space up front, either. Quality is a mixed bag, though. For every bit of supple Nappa leather or convincing carbon fibre trim, there’s a big section of hard, scratchy plastic and the odd bit of flimsy build. If I’d just spent nearly £110k on a premium performance SUV from Mercedes, I’d expect the internal door grabs not to flex.
The infotainment looks sharp and is responsive, but even with a few shortcut icons and heater controls permanently at the bottom of the screen, it could be more user friendly when you’re on the move.
Before you buy: trims and rivals
Even the base GLC 63 AMG Premium costs in excess of £108,000, mid-spec Night Edition Premium Plus just over £121,000, with Edition 1 launch models costing over £130,000. We’d stick to base trim as you get all the chassis kit you want whilst saving pounds, both in weight and cost.
The GLC’s key rival is the BMW X3 M, a car that’s significantly cheaper and refreshingly simple in comparison. Based on our experiences here, it’s not a great deal thirstier and has a more characterful engine, although it’ll be close in terms of handling.
Verdict: Mercedes-AMG GLC 63 S E
If we could sum up the GLC 63 in one word, it would be frustrating. On the one hand it handles better than its predecessor and is undeniably fast. On the other the performance feels too variable and there’s not enough of an efficiency boost in the real world to warrant the fiendishly complex and not very special-feeling engine.
If the future of performance is electric and the past is the combustion engine, the plug-in hybrid performance car feels like a bit of a dead end for CO2’s sake. Probably because it is.