The latest version of the SLK 55 AMG (R172) has a normally aspirated V8 engine (like the R171). The 415 hp V8 is of a new design and is specific to the R172 chassis. Kleemann has developed ECU tuning that not only raises the power output by 25 HP, but also drastically improves throttle response so the car feels more alive and agile, which will be sure to put a wide smile on any SLK owners face.