pipes feeding the three twin-choke Weber carburettors." 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. For the 1955 season, factory cars were fitted with a longer nose, which lengthened the car by 7½ inches and further increased maximum speed; and the headrest fairing and aerodynamic fin were combined as a single unit that smoothed the aerodynamics and saved weight. Mechanically, many features were shared with the outgoing C-Type. Its front and rear suspension and innovative all-round disc brakes were retained, as was the XK engine. Apart from the new lubrication system, the engine was further revised as development progressed during the D-Type's competition life. Notably in 1955, larger valves were introduced, together with asymmetrical cylinder heads to accommodate them. Elements of the body shape and many construction details were used in the Jaguar E-Type from 1961 to 1969. Competition history Jaguar D-Types fielded by a team under the leadership of Jaguar's racing manager Lofty England were expected to perform well in their debut at the 1954 24 Hours of Le Mans race. In the event, the cars were hampered by fuel starvation caused by problems with the fuel filters, necessitating pit stops for their removal, after which the entry driven by Duncan Hamilton and Tony Rolt speeded up to finish less than a lap behind the winning Ferrari. The D-Type's aerodynamic superiority is evident from its maximum speed of on the Mulsanne Straight compared with the 4.9 litre Ferrari's . Three weeks later the D Type won the Rheims 12 hour endurance race. For 1955 the cars were modified with long-nose bodywork and engines uprated with larger valves. At Le Mans, they proved competitive with the Mercedes-Benz 300 SLRs, which had been expected to win. Mike Hawthorn's D-Type had a narrow lead over Juan Manuel Fangio's Mercedes when another Mercedes team car was involved in the most catastrophic accident in motorsport history. Driver Pierre Levegh and more than 80 spectators lost their lives, while many more were injured. Mercedes withdrew from the race. Jaguar opted to continue, and the D-Type driven by Hawthorn and Ivor Bueb went on to win. Mercedes withdrew from motorsport at the end of the 1955 season, and Jaguar again entered Le Mans in 1956. Although only one of the three factory-entered cars finished, in sixth