The Mercedes-Benz SL63 AMG was a high performance variant of the R230 SL-Class. Introduced for the 2009 model year, the SL 63 was developed by AMG, and features a raft of performance upgrades. The most notable upgrade is the engine, which is Mercedes' M156 unit. This powerful, naturally aspirated V8 generates 518hp and 465 lb ft of torque, which is sent to the rear wheels via a 7 speed automatic transmission. Production of the R230 SL63 AMG ended in 2012, but the model series would continue in the next generation of SL as the R231 Mercedes-Benz SL63 AMG.