I've driven my car on raodtrips where there wasn't a gas station for 80 miles, and I didn't know until it was too late, and drove with the fuel light on for a long time. I pay attention to the needle, so it wasn't a big deal, but my girlfriend was taught to fuel up before she gets to ¼ tank, so she was freaking out
By the way, I always run the tank down to 10 gallons used, and sometimes run it to almost empty. I don't mind changing the filter every 2 years, or so. I'd rather run the water, and junk out. Also, you get better mileage when you don't stop for gas as often (obviously, not much better, but it's a hobby).