On the outside, there are some subtle styling tweaks on both AMG models such as the redesigned front bumper with LED daytime running lights, a more pronounced "V"-shaped grille, larger headlamps and a reworked rear bumper with newly styled tail pipes. Interior revisions are limited to the new steering wheel, higher quality trim materials and different color options.
The most important changes are hidden underneath the bonnet. Starting with the CL63 AMG, out goes the old naturally-aspirated 6.2-liter V8 and in comes the smaller yet more powerful 5.5-liter V8 with twin-turbocharging and direct-injection technology, hooked up to an AMG Speedshift 7-speed automatic. It churns out 536HP at 5,500 rpm and 590 lb-ft of torque from 2,000 to 4,500 rpm, propelling the CL63 AMG from zero to 60mph in 4.4 seconds. Add the optional AMG performance package and the output climbs to 563HP and 664 lb-ft of torque, allowing the coupe to reach the 60mph mark in 4.3 seconds. Despite better performance, the new CL63 is more environmentally friendly than its predecessor.
Meanwhile, the range-topping CL65 AMG continues to use a 6.0-liter twin-turbo V12 mated to a five-speed automatic transmission (unacceptable in my opinion). However, AMG engineers have tweaked the V12 unit which now produces an additional 17HP for a total output of 621HP. Torque remains the same at 738 lb-ft. The car is capable of accelerating from 0-60mph in 4.2 seconds. It looks like the street performance of the CL65 is not much better than its lesser brethren.