What tool do you use to measure mpg?

To measure miles per gallon (mpg), one commonly uses an onboard trip computer found in many modern vehicles, which calculates fuel efficiency based on distance traveled and fuel consumed. Alternatively, you can manually track mpg by filling up your gas tank, noting the odometer reading, driving a specific distance, then refilling the tank and calculating the mpg using the formula: mpg = miles driven ÷ gallons of fuel used. Apps and devices that track fuel consumption and mileage can also assist in this measurement.