ok so lets say i got 400 miles and when i fill up again i fill up 8.5 gallons
how to i do the math to find my mpg? is it what i started with or what i ended with in gallons... im so confused lol.

someone explain it to me plz

 

You are in the wrong forums my friend.

 

you divide the miles went by how many gallons you used.

miles/gallons=mpg

 

You would be getting 47.05882352941176470588235294 miles to the gallon yo.

 

miles/gallons