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MPG and cost-per-mile calculator
Fill the tank, note the odometer, drive, fill again. Type the numbers here.
The full-to-full method
- Fill the tank until the pump clicks off. Note the odometer.
- Drive as usual.
- Fill until the pump clicks off again. Note the odometer and the gallons you added.
- Miles driven, divided by gallons added, is your MPG for that tank.
One tank can be off, because pumps click off at slightly different levels. The average of three or four tanks is the number to trust. All figures here are estimates from the numbers you type.
Questions
Why full-to-full?
The only fuel amount you can measure is what goes in. If you fill to the first click both times, the gallons you just added are exactly what you burned since the last fill.
Why is my number different from the dashboard?
Trip computers estimate from injector timing and are often a few percent optimistic. Full-to-full over several tanks is the honest number.
What goes into cost per mile?
This tool counts fuel only unless you add your other yearly costs. Insurance, service, tires and fees usually add more than the fuel.
Track this automatically in Tagwell Auto
Log each fill-up in Tagwell Auto and it works out full-to-full MPG for you, shows cost per mile with service and insurance included, and warns you if your mileage drops by more than 15%.
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