I'm with you, man. My truck can scream low fuel at me for 20 miles and I chicken out (I pushed my 2010 Supercab to the limit and ran out as I was pulling in) and no matter what I do -- I'll NEVER put in over 29-31 gallons. I almost want to drive around with a 5 spot in the bed just as a saving grace.
I don't know why, but I never can get even close to 36 gallons, even when I travel over the magical 500 mile barrier on the highway.
Come to think of it, here in Florida some stations cut you off at either $75 or $85, depending on if you use debit or credit. It'll shut off at $85 and then only take another half gallon before it auto shuts off.
@ $3.31/gallon, that's almost 26 gallons. Then it takes less than a gallon and auto shuts off on me. That last fill up I did it was yelling at me with 30 miles to go, which if we got 15mpg (ha, which is a stretch), would be two gallons and would be 28. Where is the other 8?