Mercedes-AMG S63 E Performance 2025 review – the most powerful S-class, but by no means the best
Affalterbach's take on the S-class is an impressive machine in some respects, but those headline figures come at a cost
There’s always been a certain appeal around hot-rod limos, one that pre-dates a certain Audi racing along the French Riviera being hounded by a Citroen XM and Peugeot 605 and well before performance name tags were applied to identify them. The big-engined, high-powered limo was a discrete way to make unexpectedly rapid progress in a rather unassuming way. Such as Mercedes 450 SEL 6.9-litre, which mated a 6.9-litre dry-sumped M100 V8 engine with a three-speed auto and produced… 250bhp and 360lb ft of torque. Today’s AMG badged S-class has a slightly heavier punch delivering nearly four-times the power and a rather longer name to go with it: Mercedes-AMG S63 E Performance.
Affaltabach’s S-class for 2025 follows AMG’s familiar current recipe of mating its 4-litre hot-vee twin-turbo V8 with a hybrid powertrain that includes a two-speed e-motor to drive the rear wheels, with the nine-speed auto that takes its drive from the petrol motor to both axles. When the two outputs of both power units are combined the S63 is the most powerful AMG you can currently buy with 791bhp and 1055lb ft torque, although there is the small matter of its 2595kg kerb weight.
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Breaking those powertrain numbers down gives you a V8 that produces 604bhp and 664lb ft and a 13kWh battery that produces 107bhp of continuous energy with 188bhp available for a 10 second boost with 236lb ft also included in the mix to arrive at the final totals. Yet for all those punchy numbers the S63 doesn’t feel lightning quick. Its power-to-weight is on a par with an Alfa Giulia Quadrifoglio but it feels somewhere between a Golf R and the Alfa when you wind the modes up and throw everything at it, its size and mass making its claimed 3.3sec 0-62mph time feel less impressive than you are expecting. Or perhaps we have become anaesthetised to such numbers.
Where it does feel good for its numbers is when you roll on the throttle around 50mph to see what it can do. There isn’t a ferocious shove or violent punch but simply what feels to be a never ending wave of gathering momentum delivered in near silence aside from a noticeable increase in the V8’s decibel levels from a gentle murmur to a cat with a muffled purr. There’s more tyre noise than engine or exhaust noise and they make themselves heard even more so when you drive around on electric power alone, of which AMG claims 19 miles – expect a real world range between 10 and 15.
Despite those significant numbers, it’s not a powertrain you adapt through its seemingly endless configurability to engage with. You play around once or twice with the seven driver modes available to you but soon decide that leaving it all to its own devices is the best option and leave it to do what an S-class does best: covering big miles during long days. Although applying an AMG badge to this model has undone all that excellent S-class ride quality, with constant fidgeting and small twitches bubbling away through the car to the point of mild distraction and frustration.
Active air-suspension and ride control, roll stabilisation and rear axle steering are all part of the S63’s chassis portfolio, but even this technical make up can’t get on top of the car’s ride as it does in lesser S-class models. It’s not as if it rides on monster wheels (21 inches) or rubber band profile tyres (40 and 45 profile) - not by today’s standards that is - but somehow the application of those famed three letters has created an S-class that undoes so much of the work that has gone into establishing the S-class as one of the finest of its types for generations, to create a variant that makes little sense.
Drive it in the manner the AMG team intends you to and all the aforementioned chassis technology results in an S-class that can turn sharper, hold a tighter line and carry more speed in, through and out of a corner to a higher level and calibre than every other S-class in the line-up. Which while impressive isn’t really why you buy an S-class, is it?
You buy one for its refinement and ride quality that’s unmatched by any other series production car. For the effortless way it covers miles and the comfort of the interior that, while no longer imperious and untouchable as Mercedes interiors once where - the plastics are cheap and scratchy in places and other materials are no different to those in an A-class. And seriously, it’s 2025. Who still thinks piano black plastic is an acceptable material for, well anything? Never mind a car with a list price of £188,820 (or £200,815 as tested) - is still so welcoming and comforting that if time were on your side you’d never travel by short haul plane again. Although our first choice wouldn’t be the S63.
Price and rivals
The S-class is still the limo of choice, especially so when specced and powered to suit the model’s remit (i.e not one that’s been AMG’d and costs £188,820). In a market that continues to shrink, more compelling rivals still exist.
Audi’s A8, while it’s still with us, has a far superior quality feel about it but is only available with a diesel or petrol engine with no hybrid or pure EV running, and the closest you’ll get in terms of performance is the 563bhp S8, that starts from £113,740. BMW does offer a plug-in hybrid 7-series - and the all-electric i7, too - with the M760i e xDrive producing 563bhp and costing from £101,765 with the M model (no more power, but lots more kit) starting from £121,085. For pure opulence - and in this sector that’s what counts isn’t it? - and the ultimate you’d be best to stretch the credit facility and opt for Bentley’s latest £226,500 Flying Spur Plug-in hybrid.
