The Rolls-Royce Meteor is a British tank engine that was developed during the Second World War. It was based on the Rolls-Royce Merlin, a famous aeroengine that powered many aircraft such as the Spitfire fighter and the Lancaster bomber. The Meteor was modified to run on standard petrol and to be more suitable for tank use. It was first used in the Cromwell tank, and later in the Comet and the Centurion. This engine had a V12 configuration with a displacement of 27 litres or 1,648 cubic inches. It produced 550 to 650 hp at 2,400 rpm. It was used in British tanks until the mid-1960s.