After years of rumours claiming V8 power was en route, fresh reports say a six-cylinder engine is now destined for the AMG C63’s engine bay following lower than expected demand for the four-cylinder version.
The Mercedes-AMG C63 performance sedan is reportedly set to add two more cylinders – from four to six – after years of rumours claiming a switch to V8 power.
But the latest set of reports differ on whether the inline six-cylinder supposedly destined for the C63 will be assisted by mild-hybrid or plug-in hybrid technology – and if the C63 name will even continue for the new model.
It is the newest development in a multi-year saga claiming an engine switch for Mercedes-AMG’s mid-size hero sedan after a controversial change to a four-cylinder plug-in hybrid drivetrain that has reportedly performed below sales expectations.
In Australia, the four-cylinder has been outsold by its BMW M3 Competition rival by nearly 50 per cent, and accounts for a slimmer slice of the C-Class sales pie than the V8 did about a decade ago.
In recent days, German publication Mercedes-Benz Passion Blog – which is known for having insider sources – has claimed the C63 and lesser C43 will be axed with the C-Class sedan’s mid-life facelift in 2026, and replaced by a new C53.
It will reportedly swap the 2.0-litre turbo four-cylinder engine – with mild-hybrid tech in the 310kW C43, and plug-in hybrid assistance in the 500kW C63 – for a 3.0-litre inline six-cylinder engine from the CLE53, with mild-hybrid assistance.
Citing slow sales of the four-cylinders, it says the same change will be made to the GLC SUV for its facelift.
It claims a power output is yet to be locked in – the engine produces 330kW/560Nm in the CLE53, rising to 600Nm on overboost – but clearly states “a pure E-Performance [plug-in] hybrid system is rather unlikely for the new model”.
Overnight, a report from the UK’s Autocar has also claimed a 3.0-litre six-cylinder is coming to the C-Class – but that it will retain the C63 badge, and plug-in hybrid technology will be added.
Claiming the plans have been “confirmed to Autocar by Mercedes-AMG,” the publication reports the six-cylinder C63 is expected to produce 358kW (480 horsepower) on its own, and 485kW (650hp) with electric assistance.
It is more powerful than the 450kW version of the drivetrain used in the E53, and Autocar says the six-cylinder C63 will drop the four-cylinder’s rear axle-mounted electric motor for a more conventional one between the engine and gearbox.
What it says the C63 will not gain is a 4.0-litre twin-turbo V8 – contrary to its earlier reporting – as destined for the related, but not identical CLE63 coupe due to be revealed later this year.
The previous V8 C63 produced 375kW and 700Nm from an earlier version of the 4.0-litre engine.
Autocar reports the engine bay of the latest C-Class – which was engineered with four-cylinder engines only – cannot accommodate a V8, due to both its physical dimensions and “associated cooling systems and crash protection measures.”
The UK publication reports the German car maker is hoping for a “smoother, more characterful delivery” of power with the engine change, and matches the BMW M3 that has used six-cylinder power for most of its model life.
The facelifted C63 due next year will also reportedly adopt a new dashboard with Mercedes-Benz’s Superscreen display set, as well as new software, Autocar reports.
Speculation around the return of the V8 to the C63 has been rampant since the four-cylinder hit showrooms in Europe two years ago to – according to overseas reports – minimal customer interest.
Most recently, reports fired up on the fitment of the CLE63’s V8 to the C-Class days after Mercedes-AMG announced plans for a new-generation, flat-plane V8 that would power its next-generation models.
The German car giant has refuted reports on the V8’s return, though it has admitted it has lost sales with the downsized engine switch.
Tung Nguyen has been in the automotive journalism industry for over a decade, cutting his teeth at various publications before finding himself at Drive in 2024. With experience in news, feature, review, and advice writing, as well as video presentation skills, Tung is a do-it-all content creator. Tung’s love of cars first started as a child watching Transformers on Saturday mornings, as well as countless hours on PlayStation’s Gran Turismo, meaning his dream car is a Nissan GT-R, with a Liberty Walk widebody kit, of course.
