Microcars, known in Japan as kei cars, have been defined in different ways at different times, but they have also been known as "bubble cars" and "large fuel-effecient automobiles."
This article is about small cars. Microcar is a term often used for the smallest size of cars, with three or four wheels and often an engine smaller than 700 cc (43 cu in). Specific types of microcars include bubble cars, cycle cars, invacar, quadricycles and voiturettes, and the Japanese equivalent is the kei car. 
