Mercedes-AMG is preparing to move away from the controversial four-cylinder plug-in hybrid powertrain used in the current C 63 and GLC 63 models, signalling a significant shift in its future engine strategy.
At the recent unveiling of the Concept GT XX in Germany, a senior AMG insider confirmed to Autocar that upcoming petrol-powered AMG models will either feature an updated version of the inline six-cylinder engine or an all-new V8 equipped with a flat-plane crankshaft, a design similar to what was used in the GT Black Series.
The insider noted that while the four-cylinder drivetrain is one of the most advanced systems currently in production and delivers strong performance, it hasn’t connected with the core AMG audience. The 2.0-litre M139-based engine, when paired with an electric motor in the C63 S E Performance, delivers over 670 hp (500 kW), but its reception since its 2022 debut has been mixed. Many enthusiasts criticised the setup for lacking the character and drama of the older V8, along with its additional weight.
Although no exact end date for the engine was provided, it is expected to remain in production for now, with a gradual transition planned. A key factor behind the change is the high cost associated with updating the four-cylinder unit to meet stringent Euro 7 emissions regulations. Despite its technical sophistication, the financial investment required for compliance has proven to be a hurdle.
This shift comes as Mercedes-Benz also plans to phase out several compact models that use the M139 engine, such as the A-Class hatchback. The SL 43 4Matic is likely to move away from its current 375 hp (280 kW) 2.0-litre engine in favour of a new turbocharged six-cylinder setup.
During the same event, Mercedes-Benz CTO Markus Schäfer reinforced AMG’s ongoing commitment to a two-pronged drivetrain strategy. He emphasised that while the brand’s electric offerings will expand, hybridised internal combustion engines are here to stay. Mercedes-AMG is currently developing a brand-new V8 engine that will comply with upcoming emissions standards. This means future AMG models will continue to offer six- and eight-cylinder powertrains, all supported by either 48V mild-hybrid systems or full hybrid configurations.