How to Figure Gas Mileage

The gas pump tells us how many gallons we purchased but not how many miles per gallon we drove. Knowing how to figure gas mileage takes the mystery out of driving efficiency. Over time compare calculations to determine if mileage is lessening or even which gas delivers the best miles per gallon. The math is easy.

Instructions

1. Get a small notebook to keep in the car. A 4x6 inch spiral pad contains the space to calculate the figures, log the results and store in the glove box or console.

2. Choose the same gas station and pump if possible. A better reading is obtained after at least three fill-ups. Later, try another station and compare the findings to see if one brand gets better mileage than the other.

3. Go to a gas station to fill up the tank. Write down the station's name and location if necessary.

4. Put your vehicles trip odometer to zero. There is a knob located under the odometer. Push the knob in and release. You might have to pull it out on some cars. Check the directions in the vehicle's manual for electronic consoles.

5. Set the auto-stop lever on the gas pump trigger. The pump stops filling when the tank is full. You don't need to write how many gallons you purchased for your first time.

6. Drive until you need to fill up the tank again. Look at the odometer reading and write the number into your notebook.

7. Fill up the tank as usual with the automatic shut off in place. Write down the total amount of gallons needed to fill up. You now have the information to figure your gas mileage.

8. Figure the numbers. Take the odometer reading and divide by the gallons you just purchased. The result is your miles per gallon. Example, you drove 100 miles and bought 10 gallons of gas. Divide 10 into 100 which equals 10 miles per gallon.

Tips & Warnings

• Set the trip odometer to zero on each fill up or keep a running log of the miles and just subtract the new number from the last to obtain the current figure needed with the new fill up.

• If the miles per gallon are decreasing check the air pressure of your tires as recommended in your car manual. Keep them inflated at their proper level.

• Find the date of the last tune-up. It might be time for another if the mileage is not up to par.