economical

Small cars are usually more economical to drive because they use less fuel than large trucks.

(Chinese) 小型汽车通常驾驶起来更经济，因为它们比大型卡车耗油更少。

Buying food in bulk is an economical way for large families to save money.

(Chinese) 批量购买食品是大户人家省钱的一种经济方式。