Built as a potential Le Mans contender, the XJ13 never actually competed in any race. Its development inevitably had to take second place to the all-new very important saloon the XJ6, introduced in 1968. By the time XJ13 was complete its design had become obsolete against new cars from Ferrari, Ford and the Porsche 917. Le Mans regulations were changing and prototype cars were limited to 3 litres, unless a minimum production run of 50 were built.

Nevertheless it still remains one of the most beautiful racing cars of all time, designed by the talented Malcolm Sayer who was also responsible for the C-type and D-type. Would it have been a winner? Its 5 litre V12 engine produced 502bhp. During testing in 1967 it lapped the MIRA test track at over 161 mph in the hands of David Hobbs. That record stood until 1999.

Many of the lessons learned in the development of the V12 engine we applied to the production V12 which lasted for 25 years.