Description: History. Mercedes SL Series, presented as a prototype in 1952, was marketed in 1954 and was an immediate success. The flagship of the brand with the star was undoubtedly the 300 SL, a breathtaking beauty. Not only she enjoyed extraordinary prestige, but it was also technically very advanced for its time: it already had direct injection Bosch, and its weight relatively content, and its 215 horsepower (we are in 1954! ) made it the fastest car of all commercial cars (depending on axle ratio, it co