AMG is Replacing Its Unpopular Four-Cylinder C63 with Something Far Superior | Carscoops

      A recent report indicates that buyer indifference and the expense of complying with new emissions standards are leading to the downfall of the powerful yet impersonal engine.

      An insider from AMG has acknowledged that the controversial M139 PHEV will be discontinued. This 671 hp four-cylinder engine will be replaced by more hybrid six-cylinder and V8 engines. AMG is also developing a new flat-plane crank V8 that is anticipated to power the next C63.

      In 2022, AMG shifted the C63's direction by introducing a plug-in hybrid four-cylinder engine, but it has now conceded that this path has reached a dead end. According to a source from Mercedes' performance division, AMG is preparing to phase out the engine currently used in the C63, which controversially transitioned from a V8 to a plug-in hybrid inline-four.

      The executive, who requested anonymity while speaking to Autocar, revealed that future combustion-powered models from AMG will feature either the six-cylinder hybrid currently in the E53 or a new flat-plane crank V8 that is still under development.

      Despite the 671 hp (680 PS) 2.0-liter PHEV powertrain launched in 2022 for the C63 S E Performance generating over 100 hp (102 PS) more than the replaced twin-turbo V8, it faced backlash due to its uninspiring character and added weight. Additionally, the transition to all-wheel drive for the C63 added further weight, complicating matters for Mercedes' compact sports sedan.

      Multiple reports have indicated that dealers are having difficulty selling these models, even though the powertrain outperforms its BMW M3 competitor on paper, sharing the same robust engine used in the GLC63 S E Performance. Both AMG models contain a small 4.8 kWh battery that offers under 10 miles (16 km) of electric range.

      However, buyer indifference is not the sole factor prompting AMG to retire its dynamic M139 PHEV engines. Autocar's Greg Kable learned from the insider that the high costs associated with modifying the powerful four-cylinder units to meet the forthcoming Euro 7 emissions regulations, which are notably less stringent than initially proposed, are also a concern.

      Reports suggest that other non-hybrid models like the 416 hp (420 PS) C43 and the 375 hp (380 PS) SL 43 will also need alternative propulsion systems. The Lotus Emira, which utilizes AMG's engine, will also require a different engine, as the British brand is already searching for a V8 option.

      Looking ahead, those hoping for a swift conclusion to the C63 PHEV’s existence and a return to a traditional engine may be disappointed, as this transition is expected to take some time. The AMG source informed the magazine that the engine will eventually be retired, but since vehicles must meet Euro 7 standards by late 2026, this provides a rough timeline.

      In the interim, AMG might introduce the E53’s 3.0-liter hybrid six-cylinder into the C63 next year, which could enhance performance, but unless it receives a power increase from its current 603 hp (450 kW / 612 PS), it may not be an upgrade in terms of performance.

      Nonetheless, there is optimism that AMG's new flat-plane crank V8 will eventually be incorporated into the next-generation C63. However, this development is likely to occur toward the end of the decade, so significant changes should not be anticipated in the near future.