The CL63 AMG is powered by a new 5.5 liter twin turbo V8 engine that delivers a total of 544 hp and 800 Nm of torque. On the other hand, the CL65 AMG gets a 6.0 V12 biturbo engine with power increased to 630 hp, while peak torque remains unchanged at 1000 Nm. The Mercedes CL 63 AMG comes equipped with 19-inch alloy wheels and square exhaust pipes, while the CL 65 AMG has 20-inch alloy wheels and oval exhaust pipes. via germancarblog.com