Gas mileage is measured in mpg. For instance, if your vehicle gets 30 mpg, it travels 30 miles per one gallon of gas. The mpg is usually higher on highways compared to city driving since city driving necessitates slower speeds, idling, and higher revolutions per minute (rpm).

What is a normal miles per gallon?

The average car sold in the United States gets an average of around 25 miles per gallon (MPG).

Does miles per gallon go down?

Yes. As car's age, fuel economy declines. No matter how well you take care of your vehicle, it's engine efficiency and power are never as good as when you drive it off the lot. However, while a product of the miles you've driven, this decrease in efficiency is most likely due to faulty or worn engine components.