Packing a 500kW plug-in hybrid, all-wheel-drive drivetrain and wearing a $187,900 price tag, the new C63 is a very different car
It’s admirable when a car company doesn’t try to hide a car. The thought occurs to me on the Australian launch of the new Mercedes-AMG C63 
S E Performance as the tarmac starts to tie itself in knots as the Targa Tasmania stage unfurls in reverse. I’ve driven these roads and stages several times over the last 25 years, in both directions and in a variety of cars. And they’ve always exposed a car’s dynamic faults.
Having driven the new C63 on the international launch in Spain 14 months ago, I am aware of its strengths and (largely perceived) weaknesses. After a day lapping at the fast and undulating Ascari Race Resort, we sampled the C63 S E Performance on the writhing roads that climb out of Malaga on the coast. Aside from a generally better surface, and that oddly curious sheen that Spanish roads can get, the twists and turns in Europe were not dissimilar to the tarmac here in Tasmania. In Europe, there was a lingering impression that the new C63’s taut suspension might struggle with the rough and tumble of typical Australian roads.
First impression gliding out of Launceston in electric mode (the 13km range is more than enough to clear the city) is that the suspension, even in comfort mode has an edge to it. There’s plenty of urge in EV mode and the braking regen is natural and not overwhelming, even when in its most eco-friendly setting. Given the roads that lie ahead, I do wonder how the C63 will cope.
The second impression is that when the heavily turbocharged four-cylinder engine kicks in, the new car sounds significantly louder and more entertaining than I recall from the international launch. It’s an impression that only intensifies as the drive wears on and the throttle is buried on some of the best roads in the country. Confused, I confess my thoughts to a Mercedes staffer who is on hand and he sets me straight. The cars in Europe were fitted with gas particulate filters, while Australian-delivered cars are not. There’s more crackle and fizz from the engine and exhaust, giving a greater sense of speed and connection. Of course, it would be disingenuous to deny missing the charismatic V8 rumble of the previous C63, but equally, it’s untrue to suggest that there’s no noise or character emitted by the new car. The angrier note includes a cracking ignition cut on full-throttle upshifts, but don’t expect the aural aggression of an A45 S.
The new C63 S E Performance is one of the most technically advanced/complex cars ever made, and one that required development to start two years ahead of usual. The smallest of AMG’s super-sedans now also possesses a set of numbers like nothing else: consider 500kW, 1020Nm and a kerb weight of 2166kg. Whichever way you look at it, the new C63 is a giant.
The new car uses the rather special M139 four-cylinder 2.0-litre engine from the A45 and C43, but with a larger turbocharger to produce a huge 350kW and 545Nm, making it the most powerful series-production four-cylinder engine in the world. It’s mounted longitudinally (hence the M139l code) under the bonnet and connected to the usual nine-speed DCT gearbox. From there, drive is taken to a centre differential – yep, the new C63 is all-wheel drive – and that’s where it then meets the other propulsion source, which is a combined battery, electric motor and electronically controlled differential unit mounted on the rear axle.
The electric motor produces up to 150kW and 320Nm, and is powered by the 6.1kWh battery pack; the complete hybrid system weighs around 250kg, with the battery pack weighing in at 89kg. It’s worth noting that the 1020Nm peak torque figure is theoretical 
and is arrived at thanks to the multiplying effect of the two-speed gearbox that is driven by the electric motor. Also, the 150kW peak is available for 10-second bursts, while the continuous output is 75kW.
The mix of EV and ICE power is the really clever part, of course, with knowledge taken from the firm’s F1 exploits, and drive is then also taken to the front axle depending on the mode selected, road conditions, etc. Naturally, the C63 has a drift mode, where the centre clutch is left open and the car is permanently rear-wheel drive with both sources working together.
The engine also has a belt-driven starter motor and generator that powers the car’s ancillaries, but unlike the system used elsewhere by Mercedes-Benz it doesn’t feature a separate 48V electrical system, but rather the engine’s ancillaries and the trick electric turbocharger (to eliminate turbo lag) are now integrated into a 400V electrical set-up that works with the high-voltage requirements of the C63’s hybrid system.
The 6.1kWh battery is unique to AMG and designed specifically with fast discharge and recovery characteristics in mind, so the car can only manage 13km of purely electric running on a full charge. Owners won’t have to plug in the car, unless for pre-conditioning the car’s interior in extreme weather.
Of course, the reason for all this change is improving the C63’s eco credentials, and fuel economy is rated at 6.9L/100km on the combined cycle.
Fitting everything into the new C-class body has been no small task for AMG. The wheelbase has been lengthened by 50mm (between the A-pillar and front axle), this time not to make room for a large engine but to fit in all the additional cooling required by both ICE and EV powertrains. Widening the front guards by 73mm has enabled the fitment of broader tyres (265/35 ZR20 up front and 275/35 ZR20 at the rear), while the swollen arches provide that threatening AMG look. Standard wheels in Australia are 20-inches in diameter (19s are standard in some markets) and the standard-fit tyres are Michelin Pilot Sport 4S. The 390mm front brake discs with six-pot calipers can be upgraded to carbon-ceramics as an option, though not immediately from launch.
The front suspension geometry has been reworked, including new steering knuckles, plus more aggressive negative camber and toe angles, but the basic layout is the same as the C43’s. The rear axle has been re-tuned as well and now features rear steering that turns in an opposite direction (up to 2.5 degrees) to the front wheels below 100km/h, and with them over that speed.
The suspension itself is via coil springs with electronically adjustable and constantly variable dampers at each corner, inspired by AMG’s GT3 cars. The shell has been stiffened by the fitment of the battery pack at the rear (which also helps give a 50:50 weight distribution, front to rear). At the front, a shear panel under the engine improves the aerodynamics and also stiffens up the body, as does a strut brace.
Naturally, there is a plethora of driver modes available, including a boost function, the idea being that some of the electric motor’s thrust is kept back during circuit driving and can then be summoned at the appropriate moment by accessing the kickdown on the accelerator pedal. Apparently during testing it was found that an inadvertent spike of torque from the electric motor could seriously upset the balance of the car during on-the-limit cornering, while having all the electric power available continuously soon depleted the battery.
On a mixture of Tasmanian tarmac – some race-track pristine, some goat-track rough – the new C63 feels more in control when the dampers are switched from Comfort and into Sport. Firming up an already firm car might appear counterintuitive, but Sport brings improved body control that helps settle the C63 over both big and small bumps whether they have high or low amplitude. It’s the rear that’s particularly upset over sharper hits in Comfort, but Sport brings control without a marked uptick in firmness.
At no point on road (or track in Spain) does the C63 S E Performance feel obviously all-wheel drive, nor is it easy to detect the rear-steering in operation (some systems exhibit a spooky floatiness as you turn into high-speed corners). Instead, the chassis just exudes confidence, feeling locked down, direct and endowed with otherworldly grip. Even with ESC dialled back (or briefly off), the chassis will accept vast amounts of throttle right at the apex. There’s the occasional squirm from the back axle, but a similar amount of throttle in the old car would require a visit to the lockstops.
The steering isn’t brimming with feedback, but it’s direct and accurate, allowing you to place the C63 with confidence and precision. It’s amazing how quickly you can pick apart a challenging ribbon of tarmac, a task made easier by brakes that don’t wilt under pressure. Overall, the new-age C63 feels natural in its responses, not artificial and technically aloof. Equally, it’s not quite as organic as the older car or BMW’s M3 Competition xDrive.
Another challenge for the C63 S E Performance against the BMW is its $187,900 sticker that sits $10,100 above the Munich challenger. And BMW also offers a Touring version of its M3 Competition xDrive ($180,100), while in Australia, Mercedes-AMG has no plans to offer the wagon version of the new C63.
Where the old car won you over by wearing its bombastic heart on its sleeve, the new C63 S E Performance uses its clinical dynamic efficiency to worm its way into your affections. It’s a very easy car to like and there’s a feeling that extended exposure could lead to a love affair.