How to Figure Your Car's Gas Mileage

Gas prices are on the rise and there seems to be no end in sight. Many people are considering changing their driving habits or investing in a car with better gas mileage to help ease the pain. As a starting point for those kinds of measures, it helps to know what kind of gas mileage you're getting right now.

Difficulty: Easy

Instructions

Things You'll Need:

• car odometer in good working order
• calculator

1. The next time you visit a gas station, fill your car's tank to capacity and note the mileage on your car at that point in time.

2. Drive as usual, until your tank is on empty or near that point.

3. Again, fill your tank to capacity, noting the number of gallons it took to do that and the mileage on your car at the time of this second fill-up.

4. Subtract the mileage at your second fill-up from the mileage of your first to determine the number of miles you drove on that tank of gas.

5. Divide the miles you drove by the number of gallons it took to fill up your tank the second time.

6. Congrats, you now know the number of miles per gallon you are getting with your car.

Tips & Warnings

• If your car has a trip odometer, re-set it to zero at the time of the first fill-up and then note the total miles at your second fill-up. This will eliminate you having to note your mileage and perform the subtraction step.
• Many things can affect your miles per gallon, including weather and highway vs. city driving. To get a truly accurate picture of your miles per gallon, perform this exercise several times under different conditions.

[SharonJeanne]

on 1/8/2009 Great article! Very important and useful information.

[sunshine11219]

on 1/7/2009 good to know

[ahoier]

on 12/21/2008 I usually just reset my trip meter every fill-up. I've also learned to keep a pen in my glove box, and I'll note my trip meter reader, and Odometer reading on the back of the receipt.

But yea, if you notice a drastic decrease in gas mileage, it's likely time for a tune-up, new tires/air/alighnment/rotation/balance (or all of the above), or perhaps you just got some bad gas (pick a different station next fill up).


When I'm around town, I've leaned towards only going to three different gas stations, so if I do get a problem down the road, I can figure out what station caused it :)

[WickerWoman]

on 7/14/2008 Thanks for the refresher course, my dad also taught me this method of calculating gas mileage years ago. Those trip odometers really help.

[heatherschulte]

on 7/9/2008 Exactly how my dad taught me to do it. Nice work.