The Jaguar D-Type is a sports racing car that was produced by Jaguar Cars Ltd. between 1954 and 1957. Although it shares many of its mechanical components with the C-Type, including the basic straight-6 XK engine design (initially 3.4 litres and uprated to 3.8 litres in the late fifties), the structure of the car was radically different. The innovative monocoque construction brought aviation industry technology to competition car design, together with an aeronautical understanding of aerodynamic efficiency. Jaguar D-Types won the Le Mans 24-hour race in 1955, 1956 and 1957. After Jaguar temporarily retired from racing as a factory team, the company offered the remaining unfinished D-Types as XKSS versions whose extra 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. Total D-Type production is thought to have included 18 factory team cars, 53 customer cars, and 16 XKSS versions. The structural design, revolutionary at the time, applied aeronautical technology. The "tub", or cockpit section, was of monocoque construction, mostly comprising sheets of aluminium alloy. Its elliptical shape and comparatively small cross-section provided torsional rigidity and reduced drag.To the front bulkhead was attached an aluminium tubing subframe for the engine, steering assembly, and front suspension. Rear suspension and final drive were mounted to the rear bulkhead. Fuel was carried in the tail and the designers followed aviation practice by specifying a deformable Marston Aviation Division bag in place of a conventional tank. The aerodynamic bodywork was largely the work of Malcolm Sayer, who had joined Jaguar following a stint with the Bristol Aeroplane Company during the Second World War and later worked on the C-Type.
