Join Date: Feb 2017
Location: East TN Sevier County is Near Knoxville
I usually put nozzle down in spout. Then when it cuts off, I pull it out a bit and fill some more. Do that two, three, or whatever times.
Slops of vehicle also affects fill I imagine.
Then when talking 400 miles and say 8 gallon = 50 MPG.
Could have error in fill from various things (temperature at fill, tilt on car, point you stop filling, etc.). How Much Error, I do not know -- say 5% or 10% (seems a lot to me).
Example of 5% (0.4 Gal) --
400 / 7.6 = 52.6 MPG
400 / 8.4 = 47.6 MPG
Example of 10% (0.8 Gal) --
400 / 7.2 = 55.6 MPG
400 / 8.8 = 45.5 MPG
So, yes I agree average over a 1000 miles or more makes more sense. Likely not have more than a 1/2 gallon off on the 20 or so gallons (still make a 2.5 % error).