A suprising move made by AMG to replace the outgoing SL55 AMG with the newer M156 engine SL63 AMG. It features the newer M156 6.2L V8 used in the S63 AMG, CLK63 AMG and C63 AMG. It produces 525 PS at 6800 rpm and 630Nm of torque at 5200 rpm. It can accelerate from rest to 100 km/h (62mph) in 4.6 second going up to a limited top speed of 250km/h (155mph). Also the SL63 AMG has the new AMG developed 7-speed MCT "Multi Clutch Technology" semi-automatic transmission. This uses a twin clutch design, a first for Mercedes and AMG. It features a compact, wet start-up clutch and double declutching. it's fitted with four drive modes: "C" (Comfort), "S" (Sport), "S+" (Sport plus) and "M" (Manual) and boasts 100 millisecond shifts in "M" mode. the new car features the new AMG DRIVE UNIT with innovative Race Start function. The AMG DRIVE UNIT is the central control unit for the AMG SPEEDSHIFT MCT 7-speed sports transmission and all driving dynamics functions. The driver can change gears either using the new AMG selector lever with its leather/ carbon-fibre finish, or by nudging the AMG steering-wheel shift paddles. The new Race start Function is basicly a launch control system which enables the SL 63 AMG driver to call on maximum acceleration, while ensuring optimum traction of the driven wheels. A modified version of the SL 63 is the safety car for the 2008 Formula One season.