A desgination for Jaguar automobiles, described them as Inline 6 cylinder models. The most popular Jaguar model to date, began in 1975, discontinued in 1997. Began as 2.9L I-6, and ended with 4.0L I-6. Fuel efficent, but lacks the Jaguar preformance. Indestinguishable on the outside from the XJ12, besides the nameplate. The XJ6 has several trim levels, XJ6 (base), XJ6 Soverign, XJ6 Vanden Plas. Built as 2-door coupes, and (mainly) 4-door sedans.