Could be corrosion, or mismaintance if the truck was used before your dad brought it, or a junkyard unit. There are a lot of variables, you can't just blame it on gas entirely.

#1 Ever notice the calibration sticker on the pump? It means something. Standard tolerance is 0.2% REGARDLESS OF TEMPERATURE. This means out of every 10-gallon purchase, you are gauranteed 9.98 gallons of gas REGARDLESS OF TEMPERATURE. Doing the math, this means the most you can be shorted on your 10-gallon purchase at $3 per gallon is 5.7 cents. The DIFFERENCE in that ten gallon purchase is only 0.019 gallons if the calibration of the pump is off by the maximum allowable amount.

#2 When was the last time you had water in your tank that you could attribute to contaminated fuel? If it were bad enough, there would be a public knowledge and media event regarding it from a particular station. Have you ever mixed gasoline and water? Have you ever observed how quickly they seperate? Pour vegetable oil in the sink to experience it on a safer less-smelly level.

#3 I already stated this above, if you read my replies. However, a hot pump in a pool of gasoline won't do much for several reasons. Gasoline has a flashpoint of 246 degrees F. And that'* only going to combust if there'* OXYGEN as well. But in this case, your fuel tank doesn't have sufficient oxygen to complete the combustion. Combustion requires 3 elements. FUEL, OXYGEN, and HEAT. Take one away, and it can't happen. Your automotive design Engineers are very good. They took away the oxygen part of the equation, and dramatically reduced the heat portion.

http://en.wikipedia.org/wiki/Combustion



There are many myths and misunderstandings on this topic.

Kyle, are you going to keep quoting everything from other forums?

Not everything, I thought what I first posted was true. I like to post things on several forums to confirm or bust any info I come across

Perpetuating information on the internet like this serves several purposes:

1. It perpetuates potentially false information.
2. It costs someone else time to dispel the falsehood.
3. It costs everyone else that believes it time or money.

Do yourself a favor and:

1. Don't believe everything you read or hear.
2. Expand your mind and research the claims yourself to decide if they're truthful enough to be worthy of posting here.
3. Spend more time learning and less time on the net.
4. Question EVERYTHING at least at first.

My dad is a senior manufacturing engineer( and used to be a plant manager) for the Xerxes corporation. The largest underground fiberglass gas tank manufacturer in the US, among their other products. They've pretty much got the entire fiberglass market to themselves, and have been an industry leader for decades.

I've been inside tanks being built, and whatnot, i've moved their offices around by hand for carpet installation as well, i've read product info, and seen first hand.

There'* no membrane in there at all.... There really isn't much maintenance to them either, sure there are issues with rocks, bad digging, componentry put in the tanks, etc, but they have a long service life. As mentioned above, the ground temperature is pretty constant as well, these things are 2 feet from the surface either...

I don't really like to fillup when a tanker is there dropping his load, but if I have to fillup, i will. You have fuel filter for a reason too... My dad taught me this one, i figured he knows wtf is going on...

As mentioned, modern EFI fuel pumps are cooled by the liquid (this case gasoline) they're submerged in. running 1/4 full will pretty much guarantee even with sloshing, turning, etc it will be covered.

Although I could ask my dad any questions about this too if anyone is unclear about something..

hey willwren,, you should work for mythbusters ..

Regarding #4, I believe that pumping in the slow mode will result in getting a more accurate gallons being pumped than in fast mode; ie in fast mode you will get less gas than the pump reads. I know this used to be the case years ago but I'm not sure on the modern pumps. Can anyone confirm or deny this?