Currently, the C300 4Matic is powered by a sluggish 3.0-liter V6, only putting out 228 horsepower and 221 pound-feet of torque. That, combined with a 3,737-pound curb weight, is why the current model takes 7.1 seconds to get to 60 miles per hour and only returns fuel economy ratings of 18 miles per gallon in the city and 25 mpg highway. (For reference, a 2012 Audi A4 2.0T Quattro with Tiptronic returns 21/29 mpg.)
This new engine, a detuned version of the 3.5-liter V6 found in the C350 sedan, produces 248 hp and 251 lb-ft – gains of 20 and 30, respectively. The 2013 C300 4Matic comes equipped with fuel-saving features like an eco mode and automatic start/stop, and while official fuel economy numbers haven't been announced as of this writing, we can only assume that a modest improvement is in order.