Hi,
Here's an interesting article on how to get the greatest value when refueling -
http://money.aol.com/news/articles/_a/are-you-getting-ripped-off-by-hot-gas/20070409161209990001?ncid=NWS00010000000001 . I have always tried to refuel on the coldest days because my Father always recommended it for the reasons stated - nice to see he was right about this as well...
Happy Motoring!... Jim'99