It’s well known by now that Mercedes-AMG are developing a next-generation V8 engine following disastrous sales of the hybrid four-cylinder C63. Despite being the most powerful and fastest variant to date, the M139 powerplant lacks the charisma of its V8 forebears and buyers have voted with their wallets.

What hasn’t been confirmed is if the W206 C-Class will be a beneficiary of the V8. The new engine will enter production in 2026, however the C-Class is due a facelift this autumn, and thanks to MBpassionblog we’ve learned the four-pot C63 is going to be replaced by a 3.0-litre, turbocharged straight six when this occurs. Developing 443bhp and 413lb-ft of torque, AMG fans might be familiar with it as the mild-hybrid M256 currently powering the CLE 53 Coupé and Cabriolet.

However, the plot thickens, because there are two flavours of M256 hybrid – mild and Madras. In the E53 and GLE 53, the straight six teams up with a plug-in hybrid system, with a 158bhp electric motor lifting the total output to 577bhp and 553lb-ft. But those figures are still some way short of the existing C63’s 670bhp and 752lb-ft peaks. This begs the question: is the C63 about to become the C53?

It’s a real possibility, as the chances of the M256 being paired with the existing C63’s 201bhp electric motor and tiny 6.1kWh battery are slim. This is because the C63’s hybrid system has been developed primarily with outright performance and response in mind, rather than to offer any meaningful electric range – which is just nine miles.

The battery developed for the straight six, however, is geared more towards mileage. The e-motor is also packaged between the engine block and gearbox, whereas on the current car, it's mounted on the rear axle and uses its own two-speed transmission.

The E53 utilises a much bigger 28.6kWh battery, of which 7.38kWh are always reserved for “boosting performance driving”. The remaining 21.22kWh are enough to give the E53 an electric propulsion range of circa 60 miles with the ability to reach 87mph.

Conflicting reports claim that both flavours of straight-six powertrains are earmarked for the new AMG C53. An informed prediction thinks that the mild-hybrid straight six will feature at launch, as the chassis will require less complex re-engineering in a short space of time. Don’t rule out the plug-in hybrid model becoming available in the coming years, especially if Mercedes-Benz continues to extend the production cycles of its ICE platforms.

Offering both powertrains will also mean Mercedes-AMG can take on both the BMW M340i and G80 M3 – with the latter offering 523bhp and 479lb-ft of torque courtesy of a twin-turbocharged 3.0-litre straight six.

Mercedes-AMG will be hoping the newfound soundtrack will provide ample compensation for the reduction in power – or maybe the firm won’t be able to resist turning the wick up in true AMG fashion. One badge poised to disappear is the C43, and the GLC 43 – Affalterbach is clearly looking to consign the entire four-cylinder AMG C-Class saga to the history books.

So what do we know about the forthcoming V8? It will use a flat-plane crank, feature mild-hybrid electrification, and be a development of the existing M177 4.0-litre unit capable of meeting Euro 7 emissions standards. It’s expected to make its debut in the upcoming CLE 63 – a car which was due to launch in 2024 with the four-cylinder plug-in hybrid powertrain of the C63 S E, but has been delayed in order to facilitate a switch to the new V8.

The chances of a V8 C63 joining them in the showroom remain in the balance, given the W206’s architecture was never designed with the packaging demands of a V8. But if the six-cylinder C-Class AMG does indeed become the C53, the headroom will be there, so don’t rule it out just yet – especially with the CLE being re-engineered to accommodate two cylinder banks.