Opps. Found another one two, although some get pretty touchy on this one being just plain nutty.
Fill up with cold gas - Most non-gaseous liquids have very little thermal expansion. But.... petrol has more thermal expansion than say... water. It's not much, but it is some. So the theory goes, if you pump 25 gallons of gas at 6pm (when the sun has been beating on the station all day) the petrol you pump will be a few degrees hotter than if you fill at say 4am in the morning. The petrol expands when its hot so 25 gallons of cold gas may equal 25.001 gallons of hot gas. If theres a chemist out there they can give better figures. Perhaps it's 25.000g vs 25.100g. 12 oz of gas is a lot to me
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