Auto van Leo British Salmson was a British based manufacturer of cars, from 1934 to 1939. An offshoot of the French Salmson company, it was taken over by local management. After producing war supplies during World War II, it ceased car production, In 1929, the French Salmson company started a British branch company, Moteurs Salmson in Raynes Park, London, as a radial aero engine maker for the British Empire market. Taken over by British sports car racer Howard Martineau and investors in 1930, they renamed it British Salmson Aero Engines Ltd and continued production under license.As aero engine sales proved slow, the company extended the license deal to include local production of cars from 1934.The British S4C had the same twin-overhead-camshaft, 1471 cc, four-cylinder engine and chassis as its French parent, but the gearbox was updated to include synchromesh on the top two ratios. The coachwork was to a British design and was available in four-door saloon, sports saloon, open tourer and drophead coupé versions bought in from Ranalah or Newns. Two engines were offered, the single carburettor 12/55 and the tuned, twin carburettor 12/70. The latter was claimed to take the car to 80 mph (130 km/h). About 230 are estimated to have been made.