The Mercedes-AMG C63 is set to receive a new six-cylinder plug-in hybrid drivetrain as part of its mid-life facelift in 2026.
Confirmed to Autocar by Mercedes-AMG, the move marks a retreat from the four-cylinder plug-in hybrid system introduced in 2022, with an electrically turbocharged 2.0-litre petrol engine and rear-mounted electric motor developing a combined 670bhp and 752lb ft of torque.
Despite the C63 being the most powerful C-Class model to date, its sales have lagged well behind expectations in all of AMG’s key global markets (including the UK), forcing a rethink of its Formula 1-inspired drivetrain.
In the facelifted C-Class line-up, the four-cylinder drivetrain will be replaced by a new plug-in hybrid drivetrain featuring a 3.0-litre six-cylinder engine.
The new set-up is a development of that used in various AMG models, including the E53, GLE 53, CLE 53 Coupé and CLE 53 Cabriolet, albeit with greater power and torque.
As well as being earmarked for the facelifted C63, it’s planned to be brought to the facelifted GLC 63, due out in 2027, Autocar has been told.
Buyer resistance to AMG’s four-cylinder PHEV has already led to a decision to bring back V8 power in other parts of its line-up.
The upcoming CLE 63 Coupé and CLE 63 Cabriolet – the indirect successors to the E63 Coupé and E63 Cabriolet, due to be revealed by the end of 2025 – will receive a flat-plane-crank version of AMG’s ‘M177’ 4.0-litre twin-turbo V8.
Having a four-cylinder CLE 63 positioned above a six-cylinder CLE 53 would have made little sense to customers, according to Stuttgart sources.
Engineers involved in the C-Class programme say packaging constraints within the model’s MRA platform make the adoption of the new AMG V8 unfeasible.
“It requires more space, not just in terms of physical dimensions but also for associated cooling systems and crash protection measures,” Autocar has been told.
The current C-Class’s engine bay, optimised for four- and six-cylinder engines, would require significant structural changes to accommodate the V8 – changes that would likely necessitate a fresh round of crash testing and regulatory approval, which our sources suggest isn’t viable at this stage of the model cycle.
Instead, the facelifted C63 will use a re-engineered version of AMG’s ‘M256’ 3.0-litre turbo straight six. It’s expected to deliver up to 480bhp, or more than 650bhp in combination with an electric motor. Torque is expected to top 650 lb ft.
