Please clear up what exactly a partial fill up is.

[LDB]

If you fill the tank completely it is not a partial fill no matter how many or how few gallons. I bought a new car one week ago. I drove home and filled it to set the baseline. It only took 1.7 gallons but that was not a partial because it was completely full. But using <13.5 gallons as partial is not correct in my opinion. Good luck with your decisions.