The Rolls-Royce new Phantom, called Phantom I (Phantom I) was marketed from 1925 to 1931. It was the masterpiece of Henri Royce. In Great Britain, she replaced the Silver Ghost in 1925, and in 1926 in the United States. It was built in Derby for the English version, and in Springfield, Massachussets for the American version. The English Rolls Royce was equipped with a four-speed gearbox, the American three-speed. Its remarkable silence, unknown at the time, was due in large part to its six-cylinder engine with overhead valves with valve lifters, which gave it a total absence of vibrations. The tests of the car took place in Chateauroux, France, where Rolls Royce had a secret test center. Only the chassis and the mechanical part were manufactured by Rolls-Royce. The bodywork was installed by some of the most famous coachbuilders of the time: Park Ward, Mulliner, Hooper, Thrupp & Maberly, and even Zagato in Italy. In the United States, an additional body was designed by Brewster & Co, owned by Rolls Royce. The production was 2269 copies in Great Britain, 1243 in the United States. It was followed by the Phantom II, but only in Great Britain.