In everyday driving, the GLC 63 is much tamer than its predecessor. In Comfort mode, it sets off in EV mode (if the battery has enough charge), so there’s no engine noise or exhaust blare whatsoever, just a hushed whoosh of the motor as you glide off, with the drive going exclusively to the rear axle.
When the software determines it would be better operating in hybrid mode, the engine fires up. Drive is then channelled to all four wheels, through a nine-speed automatic gearbox and directly from the motor, making it suitably urgent.
There’s no denying the overall effectiveness of the PHEV system. When the motor contributes its full quota in Sport Plus mode, the GLC 63 is very rapid indeed – faster to 62mph than the old V8, no less.
However, it rarely if ever feels like a car packing such exuberant reserves of power and torque.
Part of this can be traced to the fact that the engine has to be wound up to 5250rpm before it delivers its full 402lb ft and 6750rpm for the 469bhp, whereas the old V8 relied on its prodigious bottom-end grunt to mould performance.
Nor is the soundtrack anywhere near as assertive as that of old. It emits a distinctive raspy exhaust note that increases in both volume and intensity as you scroll through the various driving modes, and there are some acoustic theatrics on downshifts, with pops and crackles on the overrun, but I was searching in vain for the deep, bass-driven drama that we have come to expect and appreciate from AMG models.
As compensation, it offers vastly improved efficiency. The official 37.7mpg fuel economy betters that of the old V8 by almost 16mpg, leading to a dramatic drop in CO2 emissions.
