We knew from the moment the C63 rammed down the front straight at DECA that this would be a mighty hard year to pick a top three, let alone a winner.

Of course, the two Mercs (or AMGs, if you will) are joined at the driveshaft by slightly different versions of the same M177 4.0-litre engine (nerdy fact – the AMG GT’s engine is the dry-sump M178), and both are driven at the right end. Other than that, the differences are pretty apparent.

The C63 S pumps out 375kW and 700Nm, while still returning fuel economy below 9.0L/100km. And the massive motor is backed by a clutch pack-equipped seven-speed auto transmission, while a clever electronic limited-slip diff helps to spread the prodigious output across the rear axle.

Mercedes-AMG C63 S engine

The interior, too, hasn’t missed the racer’s touch, with low-slung sports buckets facing a Dinamica-trimmed steering wheel, while a multiple-mode Drive Select toggle changes the C63’s character with a single touch; a mild-mannered family hauler is transformed into a menacing back-road assassin in a heartbeat.

Mercedes-AMG C63 S interior

New to the C-Class – and hence the C63 – is the Individual mode; my fave is putting the engine and transmission in ‘Race’ mode, the stability systems to Sports Plus and the suspension to Comfort. This gives the C63 a bit more compliance and confidence over the bumpy, damp, cold Alpine roads.

Mercedes-AMG C63 S rear

Perhaps the nicest element of all is the way the C63 flatters its pilot, no matter how ham-fisted his or her inputs may be. It’s never edgy or frightening, despite its prodigious capability, and its stability systems are so finely calibrated it’s nearly impossible to tell just how hard they are working to keep you out of the roadside scenery.

And all of this genuinely high-end performance comes packaged in a roomy five-seater with a great stereo, clever infotainment, Wi-Fi capability, terrific visibility and excellent safety credentials.

Mercedes-AMG C63 S drifting

How did it outshoot the AMG GT S, though? Its performance times were within a bull’s roar of the front bunch, and both its alpha and beta sides are more easily tapped than the always-on-point GT. Its rather large price difference did it no harm, either – if the ‘value’ part of the PCOTY equation carried more weight, you might have been looking at the winner of PCOTY 2015. Yep, it was that close.

Mercedes-AMG C63 S front driving
Mercedes-AMG C63 S burnout
Mercedes-AMG C63 S driving side

David Morley: 2nd “As much as I loved the old naturally-aspirated donk, this is just better”

Scott Newman: 2nd “A monster. Outrageous power in a practical package. Ride quality the only real bugbear”

Tim Robson: 4th “Impressively fast, but not as much fun as I expected on the track, if I’m honest”

Warren Luff: 2nd “Ultimate sleeper. Put the wagon version in my driveway and I’ll be very happy”