Learner's definition of MILEAGE
distance traveled in miles by a vehicle
My old car has a lot of mileage on it. = My old car has racked up a lot of mileage. [=it has been driven for a large number of miles since it was new]
a car with high/low mileage
The car's rental rate includes unlimited mileage. [=the rate does not increase no matter how far the car is driven]
The company pays me a mileage allowance [=an amount of money paid for every mile traveled] when I have to travel for work.
the average number of miles a vehicle will travel on a gallon of gasoline
benefit or use over a period of time