The SL-Class is comprised of two models: the SL550 and the SL63 AMG. The SL550 is powered by a 382-hp 5.5-liter V8 engine, mated to a seven-speed automatic transmission with manual mode, while the SL63 AMG boasts a hand-built 518-hp 6.3-liter V8, as well as a seven-speed MCT (multi-clutch technology) transmission with aluminum shift paddles. Both models feature a power retractable hardtop and an adaptive suspension with Active Body Control (ABC). Standard equipment on every SL-Class model includes heated leather seats, dual-zone automatic climate control, Bluetooth wireless connectivity, a voice-activated hard drive-based navigation system with four gigabytes of internal media storage and a 6-disc CD/DVD changer, along with HD and satellite radio. Safety features include four-wheel anti-lock disc brakes, an electronic stability program (ESP) with traction control, Bi-Xenon headlamps with Active Curve Illumination and an automatically deployable rollover bar, as well as front, side and driver knee airbags and the Mercedes mbrace system. The Mercedes-Benz SL-Class carries over with minimal changes for 2012. The Premium Package is now standard, featuring active ventilated front seats with AIRSCARF, an electronic trunk closer and the KEYLESS-GO passive entry/start system. Additionally, the SL65 AMG model has been dropped from the lineup.