Mercedes-Benz Museum: The Road Cars Published on November 27, 2017 in Galleries by Michel Deslauriers Photo: Michel Deslauriers 1991 Mercedes-Benz 500 SL. This car belonged to Princess Diana from December 1991 to September 1992. Engine: V eight cylinder Displacement: 4973 cc Output: 326 hp (240 kW) Top speed: 250 km/h