Mercedes-AMG Plans to Discontinue Four-Cylinder Plug-In Hybrid Powertrain

Mercedes-AMG has confirmed plans to phase out its 2.0-litre four-cylinder plug-in hybrid powertrain globally due to dwindling customer demand and high emissions-related engineering costs. This 680hp, 1,020Nm hybrid powertrain – based on AMG’s ‘M139’ four-cylinder engine – is currently used in the C63 S E Performance (sold in India) and GLC 63 S E Performance (sold globally).

Since its 2022 debut, the four-cylinder hybrid setup has faced widespread criticism due to the substantial amount of weight it adds – over 300kg – and from enthusiasts who prefer the distinctive sound and driving experience of AMG’s V8-powered cars.

Mercedes AMG ditching four cylinder plug in hybrid powertrain

One of AMG's "most advanced" powertrains, but a commercial flop

At the recent unveiling of the Mercedes-AMG GT XX electric concept, a senior insider told our sister publication, Autocar UK, that on a technical level, the 2.0-litre four-cylinder plug-in hybrid powertrain is "one of the most advanced drivetrains available in a production car. It’s also right up there on performance. But despite this, it failed to resonate with our traditional customers. We’ve recognised that."

Brand-new V8 in development at Mercedes-AMG, C 63 likely to get it

Going forward, AMG models will return to using either an updated inline-six engine or a newly-developed V8 featuring a flat-plane crankshaft. The V8 is being engineered to support 48V mild hybrid and plug-in hybrid systems, ensuring compliance with 2026-bound Euro 7 emission norms. In fact, the facelifted AMG C 63 could be powered by this new V8 when it launches in 2026.

M139 four-cylinder engine too costly to upgrade for Euro 7 compliance

Another key reason behind AMG’s pivot is the cost of upgrading the M139 engine to meet Euro 7 emission regulations. The 421hp M139 is the most powerful four-cylinder engine in the world and one of AMG’s most sophisticated designs, but the investment needed for the engine’s regulatory compliance proved too high relative to customer demand and overall market reception for the German carmaker.

The Mercedes-AMG A 45 S hatchback is expected to be discontinued soon.

The M139 engine will remain in production for the time being, but will eventually be phased out. AMG models that currently use the M139, like the A 45 S hatchback and GLC 43 Coupe, will be either discontinued or switched to inline-six engines in the near future.

Mercedes AMG still committed to EVs

AMG EVs and ICE cars to be made side by side

The newly-revealed AMG GT XX concept previews the first EV from the Mercedes sub-brand.

At the same event, Mercedes-Benz CTO Markus Schäfer reinforced AMG’s ‘two-pillar’ powertrain strategy, which entails development of high-performance EVs under the brand’s dedicated AMG.EA platform alongside offering electrified internal combustion engines. The AMG GT XX will be the first production model based on the AMG.EA platform, with an electric SUV to follow.