The Isetta is an Italian-designed microcar built under license in a number of different countries. Because of its egg shape and bubble-like windows, it became known as a bubble car, a name also given to other similar vehicles. In 1955, the BMW Isetta became the world's first mass-production car to achieve a fuel consumption of 3 L/100 km (94 mpg‑imp; 78 mpg‑US).