Mileage/ˈmaɪlɪdʒ/ Definition 1 of 4Pro Tip 1/2Fuel Efficiency Mileage often refers to fuel efficiency - how far a car goes per gallon. My new hybrid gets incredible mileage compared to my old SUV. Pro Tip 2/2Economic Consideration People consider mileage when buying cars to save on fuel costs. I'm looking for a car with good mileage to cut down on my commuting expenses.