The Mk XII was the first production version of the Spitfire to use the Rolls-Royce Griffon engine. The Griffon was a development of the "R" sprint engine used in the Supermarine Schneider Trophy racing seaplanes of the late 1920s and early 1930s. The low level performance of the Mk XII was very useful when dealing with low level hit and run raids mounted by the Fw 190, and later helped against the V-1, though the mark did not enter mass production. Only 100 were built, equipping two squadrons - No.41 received its Mk XIIs in February 1943, and No.91 in April 1943.