1. Fill up your car's gas tank completely, and reset the trip odometer (usually a button near the dashboard) to zero.
2. Drive your car for a period of time, ensuring you cover a good distance. It's recommended to drive at least 300-400 miles if possible, as this will provide a more accurate average.
3. When you fill up your gas tank again, take note of the distance traveled since the last fill, which would be displayed on the trip odometer. Let's represent it as ''D'' in miles.
4. Also, notice the number of gallons required to fill up the tank this time - let's denote it as "G" (in gallons).
5. Calculate the average mpg using the formula: Average MPG = D / G.
For example, if you drove 360 miles (D) and it took 15 gallons (G) to fill the tank, then your average mpg would be:
Average MPG = 360/15 = 24 MPG
This calculated figure represents the average miles per gallon for your car for the journey between the last two consecutive full tank fill-ups
