Mercedes-AMG C63 S E Performance 2023 review

​This is perhaps the most radical AMG ever. Why? Because it throws out the tried-and-tested, copy-and-paste formula that we associate with the brand. No more 4-litre V8 powering the rear wheels. Now we have technology in abundance, marrying multiple power sources with an all-wheel-drive system. Its hybrid powertrain generates some very large headline figures, but alongside the impressive 670bhp there is also the worrying 2165kg kerb weight. The question is, which do you feel the effects of more?

The engine is an uprated version of the M139 2-litre four-cylinder that has wowed us in the AMG A45 S. In the C63 S it is mounted longitudinally rather than transversely and it has a bigger turbocharger with its own electric motor to minimise lag. The result is 469bhp and 402lb ft (going through the familiar nine-speed multi-clutch ’box) making it the most powerful series-production four-cylinder available. However, that’s not all, because the C63 S also has a 6.1kWh battery and a permanently excited synchronous electric motor capable of producing 201bhp and 236lb ft of torque. This is deployed through a two-speed gearbox to the rear axle and is the same hybrid system used in the GT63 S and S63 E. 

With so much oomph, the 4MATIC all-wheel-drive system seems like a jolly good idea and in no small way helps the C63 S E Performance achieve its 0-62mph time of 3.4 seconds.

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The big story is the 400 volt battery which has been designed to allow both very fast charging and discharging. It has 560 individual cells and a ‘high-tech’ coolant that flows around them, keeping a consistent temperature that averages just 45 degrees Celsius. This thermal stability from the direct cooling has allowed AMG to fit the higher performance cells and it also helps the battery maintain its performance, with 70kW (94bhp) of continuous output and 150kW (201bhp) of peak performance in blasts of up to ten seconds. Its modest capacity only allows for a maximum of eight miles of pure electric driving, but it also weighs a relatively svelte 89kg including 30 litres of coolant. 

The C63 E Performance is quiet, if you’re in EV mode. Even when the internal combustion kicks in the noise is unusual because it sounds (from inside) much like a hot hatch. We’re fans of the mighty M139 four-cylinder, but it nonetheless provides a strange soundtrack for something in this segment. However, the powertrain provides smooth, easy progress in Comfort mode, turning the engine on and off without fanfare. That fast-charging battery is also impressive, with power available seemingly almost whenever it's needed. 

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In terms of its ability as a performance car, however, things are less rosy. Sadly that extra weight is all too palpable. On a good piece of road you initially sense it under braking because the C63 feels like it really doesn’t want to stop in any great hurry. It turns with surprising agility thanks to the help from the rear-wheel steering, but over bumps and lumps there is a sense that you are driving a car much bigger than a C-class. It feels happiest in its Comfort mode on the suspension, but only if you back off the ultimate pace to maintain body control. If you ramp up the speed and the damping then it starts to thump rather than soak things up.

Despite the headline figures, you can be surprisingly liberal with the throttle. The all-wheel-drive system keeps the torque largely contained; even when you throw everything at the exit of a tight corner the resultant slide is very easy to control and gather up. If anything the outright response and performance doesn’t feel as impressive as the numbers would suggest. It feels quick, but not that quick. Blame the weight. Again. 

You only get the full 150kW slug when you are in Race mode, have selected the Boost function and depressed the throttle all the way to the kickdown switch… And even then you shouldn’t necessarily deploy it at every opportunity on a track. There are boost strategies available for 70 circuits around the world and these will tell you (via graphics on the dash) when and where to apply full throttle in order to achieve the best lap time and retain as much battery for as long as possible. At Ascari, where the C63 S was launched, for example, the AMG boost strategy will see you go slightly slower over the opening half of the lap but then gain time during the second half. 

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It won’t surprise you to hear that this was all developed with input from both Mercedes-AMG's F1 and Formula E teams, for whom this sort of careful energy deployment has become second nature. It’s fascinating stuff… but fun? After a handful of these prescriptive laps, I’m not so sure. I think it would be really interesting understanding how to get the best from the car at different circuits, but there may be times when you just want to drive and not feel like you’re always holding back for fear of depleting the battery too quickly. 

In terms of the handling on track, the weight was still apparent but the balance felt fundamentally decent. You needed to be careful not to overwhelm the front end, but a bit of judicious trail braking has the rear rotating nicely and with the 4MATIC all-wheel-drive system you can get back on the throttle early with no real worries about traction. The ESP Sport setting also deserves praise for being extremely discreet.

There is so much going on with this new C63 S E Performance (even the name is complicated!) that it feels like it might take a while to really appreciate all the facets fully. It’s undoubtedly a lovely thing to spend time in, with a fabulous interior. However, there is no doubt that the 250kg that the hybrid system brings with it is palpable in the dynamics and ultimately impacts proceedings more than the mighty maximum power figure. 

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Price and rivals

The C63 S E Performance will be available as either a saloon or an estate, but given the character of the car, it feels like it makes more sense as an estate. Given that the cheapest trim for the UK market is the Night Edition, prices start at an eye-watering £98,155 for the saloon, rising £1560 to £99,715 for the estate.

The traditional rivals for the saloon are the BMW M3 Competition xDrive (£81,195) and the Alfa Romeo Giulia Quadrifoglio (£78,195) – both are not only significantly cheaper but better to drive. We’ve criticised the M3 for being a bit heavy, but at 1780kg it looks like a paragon of Chapman philosophy compared to the AMG. However, neither the BMW nor Alfa has the ability to travel on purely electric power, which understandably might be important to some buyers.

The estate’s biggest rivals are the Audi RS4 Competition (£84,600) and BMW's excellent M3 Touring (£86,570), both lighter the hybrid C63, but don’t offer the potential practicality of an EV mode.

Mercedes-AMG C63 S E Performance specs