How do you calculate your car's fuel efficiency?

Answer by  tkarlav (1502)

You can empty the tank then see how much gas fills it . drive it till empty take the total gallons filled divided by miles traveled and you got average.

Answer by  Matt89 (177)

Take the miles you traveled from filling your car to it being empty (example: i drove 385 miles on one full tank of gas). Now with this number you would multiple it by the gas tank size (example: Acura Integra's have a 13.2 gallon tank) and then divide by 2.

Answer by  Amber40 (24961)

Fill your gas tank up and record the mileage. Drive normally then when you fill up record the amount of fuel added and the mileage. Divide the miles by the gallon. Take this and recorded it. Repeat this then take an average of the results to get an average mpg.