You know the mileage your car is supposed to get, but you're not sure if you're getting what you paid for. Advertised gas mileage on cars is based on an average of test vehicles, and will vary depending on your personal driving habits as well as the speed and traffic conditions in which you drive. Here's how you can check your gas mileage to determine your own personal vehicle's rate of miles per gallon of gas.
Fill up your vehicle's gas tank with fuel and note the miles on the odometer (or set the trip meter to zero).
Drive your car as you normally do until the fuel level is at or below one quarter tank.
Refuel your vehicle, this time noting both the odometer reading (or trip meter) and the gallons of fuel needed to fill the tank.
Subtract the beginning mileage from the ending mileage; this is your total mileage per tank.
Divide your total mileage by the gallons of fuel needed to fill the tank. This is your gas mileage.
Example: 350 miles driven divided by 10.6 gallons equals 33.02; rounded off equals 33 miles per gallon.
