Hubraum
Engine displacement began at 3.4 litres, was enlarged to 3.8 L in 1957, and reduced to 3.0 L in 1958 when Le Mans rules limited engines for sports racing cars to that maximum. D-Types won Le Mans in 1955, 1956 and 1957. After Jaguar temporarily retired from racing as a factory team, the company offered the remaining unfinished D-Types as street-legal XKSS versions, whose perfunctory road-going equipment made them eligible for production sports car races in America. In 1957 25 of these cars were in various stages of completion when a factory fire destroyed nine of them.