The AMG community is not happy. The most potent AMG C-class, the C63, surrendered the V-8 for a turbocharged hybridized four-cylinder engine, and the impending E63, the next top-of-the-line E-class, will get by with an inline-six plug-in hybrid system. Some claim that this isn't competitive enough to compete with the twin-turbo inline-six BMW M3 and the upcoming hybrid twin-turbo V-8 BMW M5. An planned V-6 hybrid engine with up to 640 horsepower will also power the Audi RS5 and RS7.

The M177 4.0-liter V-8 engine, which will return to the C- and E-class in 2026, is the only way out of this pickle, according to two separate sources. To comply with EU7 emissions regulations, the eight-cylinder is now undergoing modifications. The 831-hp AMG GT63 S E Performance and the 791-hp AMG S63 both employ this engine, and both of those vehicles pair it with a hybrid system.

Senior engineers directly involved with the project claim that just modest bodywork modifications are required for the twin-turbo engine, the PHEV battery and electric motor, and the ancillary equipment to fit in the C-class and E-class. The C- and E-class are being looked at potential life cycle extensions through 2028, so the hard-core AMG models may continue to be produced long into the next 10 years.