hehehehe........when my truck says empty, let me tell you, it means empty!!
when I get to about a quarter tank or below, I can see the gas gauge move up and down as i go around corners and up and down hills.... about the time it hit the red part, it will stop doing this. From there, I can drive about 3 miles before stalling. Durring those 3 miles, if you take any left turns, you will stall for a minute untill the gas flows back to the other side of the tank.
mt dad's blazer has a display that tells you how many miles you can drive beofre running out of gas. It is quite handy, i don't even have to look at the guage.
i have no clue about my mom's car, it usually gets filled up before it gets to an 8th of a tank or so....