I've always filled up before my "miles remaining" indicator went to zero. If you let it go down to zero what does it do from there? Stay at zero? Go negative? Scold you for not filling up?

Just stays at zero - nothing else - unless you go so far as to run out of gas! I've had just over 2.5 gallons left at 0 miles to empy, and 2.9 left when I took it to 13 miles to empty.

I did this once - it had dashes showing where the miles would be.

I've driven about 10 miles after the "remaining miles" got down to zero - the display stayed at zero. I've never seen dashes. I filled it up to the top of the filler neck and it held 16.2 gallons.

Maybe it causes a rip in the Time/Space Continuum... No, wait! That would be a Star Trek reprecussion!