The Isetta is a city car (i.e., a car characterised by its small size, practicality, and low fuel consumption) produced by the Italian car manufacturer Iso based in Bresso (Milan) between 1953 and 1956 and, under licence, by the German company BMW between 1955 and 1962. The BMW 250, the German Isetta, retains all the insights of the Iso, with the addition of a small but effective heating system and sliding side windows. From a mechanical point of view, the novelty lay in the adoption of a 4-stroke engine, with a slightly modified displacement (245 cc) which justified the new name, and power increased to 12 HP. In 1956, this version was joined by the 300 with an upgraded 13 HP engine.