With the 917, Porsche for the first time entered the league of immensely powerful, large-capacity racing cars. The 580 hp from the twelve-cylinder 4.5-litre engine of the 917 set new standards, to the extent that even decades later, independent experts rate this Porsche as one of the most impressive sports cars of the century.
Changes in the regulations motivated Porsche to build the 917. Prototypes were allowed a maximum engine size of three-litres, and for sports cars five-litres were allowed.
