Hey it looks like the mpg displayed next to the car in the avatar window is the average of the mpg calculations where the average is the sum of the mpg divided by the number of entries. This is not accurate because a high mpg reading with 1 gallon of gas offsets the low reading with 10 gallons of gas with the same weight. You need to add all the miles driven and divide by the total of the gas used to calculate the mpg.
Hey it looks like the mpg displayed next to the car in the avatar window is the average of the mpg calculations where the average is the sum of the mpg divided by the number of entries. This is not accurate because a high mpg reading with 1 gallon of gas offsets the low reading with 10 gallons of gas with the same weight. You need to add all the miles driven and divide by the total of the gas used to calculate the mpg.