The new M139 four-cylinder turbocharged engine that powers the new Mercedes-AMG A45 is a prime candidate to replace the 4.0-liter bi-turbo V-8 powerhouse found under the hood of the Mercedes-AMG C63 super-sedan, with a little help from the wonder of electricity. As a result, the next-generation 2022 C63 will be powered by a 2.0-liter turbo engine boosted by a 48-volt electric system - and before you start frowning, get this: the new powertrain will be just as potent as the V-8 and then some.
Autocar got word from unnamed “Affalterbach insiders with knowledge of AMG’s new model plans” that the V-8 currently serving the Mercedes-AMG C63 will be dropped in favour of a four-cylinder hybrid drivetrain. The likely candidate to fill the ICE position is none other than the freshly-coined M139 four-cylinder turbocharged mill used by the new Mercedes-AMG A45, CLA45, and GLA45.
The 2020 Mercedes-AMG C63 won’t debut earlier than 2022, so theoretically, the timeframe would allow Affalterbach to design, test, and perfect the powertrain which will get, according to the same source, a 48-volt starter motor located inside the gearbox. Apparently, the setup will be similar to the one used by the M256 3.0-liter turbocharged inline-six engine that moves the CLS 53 4Matic+, however, the e-motor is likely to offer superior boost ability and will also work together with the nine-speed Speedshift transmission. Presently, it adds 22 hp and 184 pound-feet of torque to the overall grunt tally.
What’s more, the new powertrain is touted as capable of matching the current V-8’s power output of 503 horsepower and surpass its levels of grunt by 37 pound-feet, for a maximum of 553 pound feet of twist - the 4.0-liter bi-turbo V-8 in the outgoing C63 makes do with 516 pound-feet of twist.
Now, with the V-8’s performances going nowhere, the biggest advantage of this new hybrid drivetrain would be its low weight.
The new M139 2.0-liter unit comes to replace the 376-horsepower M133 engine and it is available in two outputs, with 382 horsepower/354 pound-feet of torque and 416 horsepower/369 pound-feet of torque in the “S”-badged models. That’s 208 horsepower per liter or 104 horses per cylinder, whichever you want to look at it.
Moreover, the engine has been rotated around by 180 degrees, which in turn allowed Mercedes-AMG’s engineers to position the turbocharger and the exhaust manifold in the engine’s rear. That’s not a random occurence, as the change clears the way for a flatter and more aerodynamic front section of the car that uses this engine. The compressor and turbocharger are also fitted with roller bearings, just like the 4.0-liter V-8 in the AMG GT 4-door Coupe.
The M177 bi-turbo “hot vee inside” V-8 found inside the current Mercedes-AMG C63 is also derived into two outputs: 469 horsepower/479 pound-feet of torque and 503 horsepower/516 pound-feet of torque in the “S” variants. The resources are handled by the nine-speed AMG Speedshift MCT transmission and allow the rear-wheel drive C63 S Coupe to sprint from 0 to 60 miles per hour in 3.7 seconds (3.8 seconds for the C63 Coupe).
Further reading
Read our full review on the 2018 Mercedes-AMG C63.
Read our full review on the 2019 Mercedes-AMG C43.
Read our full review on the 2018 Mercedes-Benz C-Class.