The C63 AMG is the heaviest version of Mercedes’ C-Class coupe for one simple reason: it’s got a big 6.2-liter V-8 engine under the hood. That engine produces 451 hp in standard guise or 481 hp if buyers opt for the $6050 AMG Development package, and a seven-speed automatic transmission transmits that power to the 18-inch rear wheels. Mercedes claims a 0-to-60-mph time of 4.4 seconds for the standard car and 4.3 seconds for those with the AMG kit. Top speed is normally limited to 155 mph but raised to 174 mph with the AMG package. Other versions of the C-Class coupe are significantly lighter, owing to their smaller engines and brakes, and reduced equipment levels. The C250, which has a 201-hp, 1.8-liter turbo-four engine, weighs 3538 pounds. The 302-hp C350 coupe tips the scales at 3693 lb with rear-wheel drive and 3737 pounds with 4Matic all-wheel drive.