It’s a known fact by now that the next-generation Mercedes C-Class and S-Class in AMG flavours are going to adopt a plug-in hybrid powertrain. The reveal was made by Affalterbach’s boss Tobias Moers last month in an interview during which he also confirmed plans for an amped-up hybrid GT to rival the Porsche Panamera Turbo S E-Hybrid.

In a separate interview, the very same Tobias Moers admitted the new four-cylinder 2.0-litre turbocharged engine (pictured above) powering the A45 and CLA 45 could be installed in larger models. Putting two and two together, we’re not entirely surprised that Autocar is now reporting the new C63 could switch to an electrified four-pot.

Gallery: 2021 Mercedes C-Class Saloon new spy photos

Eschewing the twin-turbo 4.0-litre V8 of the current-gen C63, the new performance model from Mercedes could use an adaptation of the M139 unit powering AMG’s compact cars. In those vehicles, it produces as much as 416 bhp and 369 pound-feet of torque, and an electrified version could pump out even more muscle.

According to Autocar, the engine will allegedly boast a 48V integrated starter motor in the same vein as the one used by the larger inline-six M256 unit found under the bonnet of the CLS 53. In the swoopy saloon, the electrified component adds 22 bhp and 184 lb-ft, but AMG is looking to upgrade the system and squeeze out “significantly more power” for the next C63.

Despite losing half of its cylinders, the C63 is expected to match the 503-bhp of the current model in "S" guise while gaining 37 lb-ft of torque to deliver 553 lb-ft. Even with the added hybrid hardware, the entire powertrain is expected to weigh less than the M177 installed in today’s C63.

Switching to a four-cylinder unit is not the only big change Mercedes-AMG is preparing as the C63 saloon, coupe, and convertible will employ a 4Matic all-wheel-drive system. Purists will at least take comfort from knowing a Drift mode similar to the E63’s will send all power to the rear axle by decoupling the front driveshaft.

The regular C-Class Saloon (W206) is rumoured to debut at the 2020 Paris Motor Show next September, so don’t expect to see the revamped C63 sooner than the second half of 2021. Once again, there’s also going to be a lesser AMG version, but likely not today’s C43 as Mercedes will introduce a C53 with a de-tuned version of the C63’s electrified powertrain.