By Nat Shirley
Monday, Dec 31st, 2012 @ 4:27 pm
 
The days of AMG's 6.2-liter V8 are officially numbered. A twin-turbocharged 5.5-liter V8 has replaced the mill in nearly all of AMG's offerings, and now Mercedes-Benz has confirmed that its performance division is working on another downsized motor to take its place in the next C63 AMG.

Unlike the new-generation BMW M3, the C63 AMG won't switch to a six-cylinder setup - Mercedes has confirmed an Autocar report suggesting that new motor is a turbocharged 4.0-liter V8. The motor is said to be derived from the 2.0-liter four-cylinder that's earmarked for the A45 AMG and CLA45 AMG, with the two motors sharing critical measurements such as individual cylinder capacity and bore center spacing.

Known internally as the the M177, the forced-induction eight will produce between 460-500 horsepower under the hood of the next hot-rod C-Class. It will also be utilized in the replacement for the SLS AMG, in which capacity it will bear the M178 designation and make roughly 590 horsepower.

In addition to replacing the final examples of the 6.2-liter V8, the M177/M178 could also eventually supplant AMG's existing twin-turbo 5.5-liter V8.

The model designation to be used for the vehicles powered by the M177/M178 is a mystery. Due to the upcoming A45 and CLA45 AMG models, which feature a turbocharged 2.0-liter four-cylinder, the "40" moniker won't be used - though accurate in terms of displacement, its lower numerical value wouldn't fit Mercedes' naming hierarchy. Instead, the "60" designation could be applied, or Mercedes could simply stick with the current, well-known "63" badge.

Photo by Mark Elias.