Japanese Kei cars are the smallest highway-legal passenger cars, created by the Japanese government in 1949 and are one type of microcar, which are generally known as a small fuel-efficient automobile, which can have three or four wheels.
The kei car category was created by the Japanese government in 1949, and the regulations have been revised several times since. Kei car (or keijidosha , "light automobile", pronounced [kedidoa), known variously outside Japan as Japanese city car, ultramini, or Japanese microcar, is the Japanese vehicle category for the smallest highway-legal passenger 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). 
