The 2016 Mercedes-Benz AMG SLK is available as a 2-door, 2-seat convertible. Starting at $72,600, the 2016 Mercedes-Benz AMG SLK AMG SLK 55 is powered by a 5.5L , 8 - cylinder engine that returns an EPA estimated 19-mpg in the city and 28-mpg on the highway.