Louis Hervé Coatalen joined Sunbeam in 1909, and although he spent a lot of time developing race and record breaking cars, he also found time to do production models. The Sunbeam 12/16 was introduced in 1910 with Coatalen-designed 2.4litre, 4cylinder engine cast in two blocks. The engine drove the rear wheels by means of a shaft rather than the chain drive used by most manufacturers. The 12/16 was improved for 1912 with a monobloc engine and 4speed gearbox. In 1915 the 12/16 evolved into the Sunbeam 16 with the engine enlarged to 3-litres and a new upright radiator replacing the squatter squarer one. The Sunbeam 16 halted production in 1916 for war work and resumed in 1918 being upgraded with a new overhead valve engine as the Sunbeam 16/40 in 1922. A new Sunbeam 16/50 was announced in 1924