fuel economy

:  a material used to produce heat or power by burning

:  nutritive material

:  a material from which atomic energy can be liberated especially in a reactor

:  to provide with fuel

:  support, stimulate

:  the management of household or private affairs and especially expenses

:  thrifty and efficient use of material resources :  frugality in expenditures

:  an instance or a means of economizing :  saving

:  designed to save money