economical
adjective
uk/ˌiːkəˈnɒmɪkəl, ˌekəˈnɒmɪkəl/ usnot using a lot of fuel, money, space, etc.:
What's the most economical way of heating this building?
Most printer software lets you fit four pictures per sheet to make the most economical use of the space available.
There's increasing demand for cars which are more economical on fuel.
It's a shame this industry could not be a bit more economical with the costs.