The Jaguar XK dual overhead camshaft (DOHC) inline 6-cylinder engine was introduced in 1949 and continued in manufacture until 1992. It was produced in five displacements for Jaguar passenger cars, with other sizes being made by Jaguar and privateers for racing. In contrast with contemporary BMW and Mercedes engines, the original XK engine was relatively unstressed and produced high torque thanks to its more advanced valve and head configuration.