Mercedes readying new AMG engine

Mercedes-Benz is working on a naturally aspirated version of the 5.5-liter V8, slated for use not only in the refreshed SLK55 roadster, but in the AMG-fettled version of the upcoming C-Class coupe, the C55. 

This new mill is claimed to produce around 422 horsepower – 62 more than what's currently available in the SLK55. New technologies like a cylinder cut-off mechanism will help improve fuel consumption while still sending a larger helping of power to the car's rear wheels.

There are also reports that while the upcoming C55 AMG coupe (and its hardcore Black Series version, which is rumored to be in the cards) will use this new 5.5-liter motor, the four-door C63 AMG sedan will retain the 6.2-litre V8.  

Source: AutoWeek