four-wheeled light vehicle
Refers to a four-wheeled vehicle that falls under the Japanese light vehicle (軽自動車) category, such as a kei car or kei truck. Often used in contrast to two-wheeled light vehicles.
See also: 軽自動車
Four-wheeled light vehicles are popular because their maintenance costs are low.
Compound of 軽 (kei, 'light') + 四 (yon, 'four') + 輪 (rin, 'wheel'). The reading よんりん is a standard combination of 四 (yon) and 輪 (rin).