How do I measure my vehicle’s fuel efficiency?

A. Follow these instructions to get an estimate of fuel consumption.
1a. Fill your fuel tank until the first ‘click’. No need to record this fuel volume because you will not add it into the calculation. You fill the tank so that you always have the exact same reference point to calculate fuel added.
1b. Reset the trip odometer and/or record the ‘initial total’ odometer reading.
2. Drive until you need fuel (as normal).
3a. Fill fast until the first ‘click’. Fill slowly until the second ‘click’.
3b. Record the trip odometer and reset and/or record the ‘total’ odometer reading.
3c. Record the volume of fuel added.
4. Repeat steps 2-3 at least 3 times.
5. Divide the total distance traveled by the number of liters/gallons (this measures the number of kilometers/miles you get per liter/gallon of fuel). Be sure to add the fuel for the ‘end’ fill to the total fuel volume.   It is not necessary to fill the fuel tank every time. Only to ‘start’ with a fill and ‘end’ with a fill, keeping careful records of fuel added between the first fill and the last fill.
We offer a Fuel Savers Log to help record keeping.
Here is a PDF sample page of our Fuel Saver’s Log.
Here are instructions for filling out our Fuel Savers Log.
Here is a calculator to find out how much money you’ll save.Adjust the percentage to fit whatever technology you are using.http://www.eagle-research.com/fuelsav/FiveYrCalc.php
See fuel prices nationwide http://www.gasbuddy.com/