The first ever Jaguar XJ was launched in 1968 with the six cylinder XJ6. In 1972 Jaguar introduced the V12 powered 5.3 Liter XJ12, at that time the only mass production four door automobile featuring such a large engine. Jaguar also claimed to sell the potential buyer the “fastest full four-seater available in the world today”. As seen on this site, other manufacturers already claimed this status with the Maserati Quattroporte I or the Iso Rivolta S4/Fidia. The engine was a newly developed machine which was first deployed as of 1971 in the Series 3 E-Type. The XJ12 and XJ12L (Long wheel base version) were visually nearly the same as the XJ6, only the bonnet grille, badging and painted steel wheels were different. The XJ12 was also the most luxurious of all early XJ-cars with e.g. automatic transmission as standard (no manual option available) and all leather interior. In 1973 the first XJ12 was already replaced by the new Mark II XJ car, therefore the Mark I XJ12 is the most unique twelve cylinder XJ ever made with just over 3,000 cars produced.

Technical specification Jaguar XJ12 Mark I: