The original process was invented by Franz Fischer and Hans Tropsch while working at the Kaiser Wilhelm Institute in the 1920s. Since then, many improvements have been made. The term "Fischer-Tropsch" now is used for many similar processes. Fischer and Tropsch submitted several patents, like US patent no. 1,746,464, applied for in 1926, and published in 1930. It was given to the factories in Germany in 1936. Germany had an abundance of coal but very little petroleum. The F-T process enables the conversion of coal into gasoline, which is important for gasoline-based transport like cars, airplanes, and trucks. As a result, during World War II, the F-T process enabled Nazi Germany and Japan to produce substitute fuels for tanks and cars. F-T fuel production made up about 9% of German wartime fuel production and 25% of the automobile fuel.