SL65 AMG Mercedes' in-house AMG Performance Studio tweaks the 6.0L V-12 bi-turbo engine for a full 670 hp -- 58 horses more than the SL65 -- while the torque figure remains identical at an electronically limited 738 lb-ft for drivability reasons (AMG claims that 885 lb-ft would be available in derestricted form). To achieve these gains, larger turbochargers were developed specifically for this application, while a new AMG sports exhaust and optimized airflow tubing round out the power boost. The result is a heart-pounding 3.9 sec sprint from standstill to 62 mph and an electronically limited top speed just a single mph shy of the magical 200-mph mark.