What is a definition of miles per gallon?

Question

What is a definition of miles per gallon?

Answer 1

It is how many miles a car travels on one gallon of gas

Answer 2

the definition of mpg (miles per gallon) is how many miles you can drive per gallon of gas

Answer 3

it is how many linear miles your car can drive for one gallon of gas. Most aren't accurate, and they never include idle time, red lights, stop and go traffic. And at this point... It'd be better to ride a bike!

Answer 4

Or in England, it is how many miles you travel on 1 gallon of PETROL ;)  

( Most cars use Petrol, not many are converted for Gas)

And why do the British get more miles per gallon than the Americans ?

Because there are 4.546 litres per UK gallon but only 3.785 litres per US gallon.