I know that my tank is 20 gallons, but when I fill up, the gauge only goes to the little mark just before "F". I always fill up at no less than a quarter tank, but I realized that I'm only putting around 10 gallons each fill up. What could be the cause of this?

 

Same happens to me! I thought maybe just my needle and bobber are dead...I hope its nothing serious

 

Yeah, I'm filing up every 3 days or so, doesn't feel like I'm paying as much when I put in only 10 gallons instead of 17-ish! I'm thinking that something like the bobber is the problem, but hoping to get a more educated hypothesis before proceeding. Maybe when I replace the fuel filter next year, I'll be able to fix this issue.