The Mercedes-Benz 300 SLS was designed in 1957 for the American Sports-Car Championship. The car was based on the 300 SL production sports car and converted into a competitive car for this series by reducing its weight to 970 kg and boosting its power output from 215 to 235 hp. The American Paul O'Shea won the title three times in succession from 1955 – twice at the wheel of a 300 SL Coupé and once, in 1957, in a 300 SLS.
The racing activities of the eight-cylinder 300 SEL 6.3 saloon did not extend beyond a single race (the six-hour touring-car race in Macao in 1968, won by Erich Waxenberger). Subsequent motorsport involvement was curtailed by the oil crisis. Mercedes-Benz did not appear again on winners' lists until 1977. In the London–Sydney marathon rally, the teams of Cowan/Malkin/Broad and Fowkes/O'Gorman recorded the fastest overall times in Mercedes 280 E works vehicles. A thoroughbred racing saloon of this type even lined up at the start of the East African Safari rally in 1978.