5.5L/530HP Bi-Turbo V8 - 7-Speed Auto AMG Speedshift - Premium 1 Package - Driver Assistance Package - Soft Close Doors - Staggered 19/20-Inch AMG 10-Spoke Forged Wheels - Fast, Fun, and Full of Luxury Options. The SL63 adds...the M157 AMG twin-turbo 5.5-liter V-8 developing 530 hp and 590 lb-ft.... As with the last SL63 AMG, out goes the torque converter from the seven-speed automatic, replaced with a wet clutch. The chassis upgrades include an AMG-spec ABC active-suspension setup with two settings, electromechanical constant-ratio steering, and upgraded steel brakes. All this comes together with a goal of raising the performance level of the SL without dramatically sacrificing the comfort of the SL550.