Currently reading: 2026 Mercedes-AMG C63 to drop PHEV four for new PHEV six

Sales of the existing car have lagged well behind expectations, despite being the most powerful C-Class model to date

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.

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 – 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.

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In the current E53, launched in 2024, a less powerful version of this drivetrain delivers a combined 576bhp and 553 lb ft of torque, with 443bhp and 413 lb ft of that from the petrol engine alone.

The C63's new PHEV drivetrain is set to ditch the current rear-axle electric motor mounting of the current 'P3' layout in favour of a 'P2' arrangement, with the electric motor placed between the engine and gearbox.

The 'M256’ engine's relatively compact packaging – a result of it using a 90mm bore spacing – makes it well-suited to the C-Class platform.

With this set-up, AMG hopes to balance performance targets with a return to the smoother, more characterful delivery associated with the earlier, V8-powered C63. 

Other changes set for the facelifted C63 include the adoption of a new dashboard featuring Mercedes' Superscreen display in combination with the MB:OS operating system. 

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benzinjection 9 April 2025

Recent reports indicate that Mercedes-AMG plans to reintroduce the V8 engine in the C63 model by 2026, moving away from the current 2.0-liter four-cylinder plug-in hybrid (PHEV) setup. This decision is reportedly in response to customer feedback and slower sales of the downsized powertrain.Autocar+1Carscoops+1

The anticipated V8 engine is expected to be a revised version of AMG's twin-turbocharged 4.0-liter unit, potentially featuring a flat-plane crankshaft to enhance throttle response and achieve a higher RPM redline. This configuration may necessitate the use of artificial sound technology to replicate the traditional V8 exhaust note.Mercedes-Benz Worldwide+5Autocar Professional+5bull-leds.in+5Autocar Professional+4Autocar India+4autofans.in+4

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scrap 8 April 2025

Odd that the V8 no longer fits, given this car sits on the same platform as the previous C class. 

mdouth258 7 April 2025

Does anyone check the details of an Autocar article before it gets posted? Might want to double check whether the M3 has used a six-cylinder engine since 2000 or not.