Designed specifically to win the Le Mans 24-hour race, it shared the straight-6 XK engine and many mechanical components with its C-Type predecessor.

Its structure, however, was radically different, with innovative monocoque construction and slippery aerodynamics that integrated aviation technology, including in some examples a distinctive vertical stabilizer.

Its elliptical shape and comparatively small cross-section provided torsional rigidity and reduced drag.

Philip Porter, in his book Jaguar Sports Racing Cars, says that "[a] more likely reason was to provide extra space for the ram pipes feeding the three twin-choke Weber carburettors.

"[4] Reducing underbody drag contributed to the car's high top speed; for the long Mulsanne Straight at Le Mans, a fin was mounted behind the driver for aerodynamic stability.

Its front and rear suspension and innovative all-round disc brakes were retained, as was the XK engine.

Although only one of the three factory-entered cars finished, in sixth place, the race was won by a D-Type entered by the small Edinburgh-based team Ecurie Ecosse and driven by Ron Flockhart and Ninian Sanderson, beating works teams from Aston Martin and Scuderia Ferrari.

In 1955, for example, a 1954 works car on loan to Cunningham won the Sebring 12 Hours in the hands of Mike Hawthorn and Phil Walters, and in May 1956 the team's entries for Maryland's Cumberland national championship sports car race included four D-Types in Cunningham's white and blue racing colors.

[citation needed] After Jaguar temporarily retired from racing as a factory team in 1956, the company offered the remaining unfinished D-Types as XKSS versions whose additional road-going equipment—including a passenger seat, passenger-side door, side windows, full-width framed windscreen and windscreen wipers, trimmed interior, folding hood, and bumpers—made them eligible for production sports car races in America.

On the evening of 12 February 1957, a fire broke out at Jaguar's Browns Lane plant and destroyed nine of the 25 cars that were in various stages of completion.

[7] Jaguar announced the planned production of 25 D-Type "continuation" vehicles to be hand-built at the Warwickshire, UK workshop to complete Jaguar's original goal of producing 100 D-Type based cars (the last twenty-five of which were to be turned into road-legal XKSS versions).