The last quarter is fine. That's 1/4 of a tank of gas. That's still plenty to keep the pump good. It's regularly running the fuel gauge to the bottom of E past the light coming on that's bad for the pump.

 

If youve ever pulled the fuel pump out, the assembly that the pump sits in keeps the pump submerged no matter what the level of the tank is. The assembly has a hose, from the filter or maybe return line?, that constantly flows fuel into the assembly

 

I have a commute of 60 miles per day, I fill up 2x a week. I average 30.5mpg and usually drive 420 miles per tank. I fill up with 13.2 consistently... I only use 91 octane NON-ethanol fuel. When im stuck and have to use 93 octane E10 fuel I get 27.5-28mpg...

It goes back to 30.5-31mpg when I fill back up with non-ethanol. I have driven a mile or so on -0- miles to empty, cringing the whole time!

my life is that exciting.