The Mercedes-Benz SLK55 AMG was the performance focused variant of the R171 SLK-Class.Introduced for the 2005 model year the SLK 55 AMG featured a range of improvements and upgrades over standard SLKs, including improved brakes, lowered suspension, and a body kit. Power for this line of performance roadsters came from Mercedes' M113 5.4 engine, which was a 5.4L V8 that generated 355hp which was sent to the rear wheels via a 7 speed automatic transmission. Production of the R171 SLK55 AMG lasted until 2011, but the model series would continue life in the next generation R172 SLK-Class as the R172 Mercedes-Benz SLK55 AMG.