Microcars have been defined as "very compact, small-engined cars, designed for use in large cities, especially in Japan".
Microcars have also been defined as being a "small car, popular in the 1950s, that featured a body offering full weather protection and mechanics often derived from motorcycle technology",[2] though in the 1950s, a trend towards egg-shaped cars with a relatively large ratio of windows to bodywork meant that the affectionate term bubble car was used.
[3] The term microcar is usually applied only to such small cars built after World War II; cars built prior to the war are more generally referred to as cyclecars.
However, one dictionary definition states simply that a microcar is "a small fuel-efficient automobile".
[4] An attempt at a more specific definition for microcars suggested by some enthusiasts is "economy vehicles with either three or four wheels, powered by petrol engines of no more than 700 cc or battery electric propulsion, and manufactured since 1945".