The liquid gasoline expansion rate is almost 5 times higher than water.
In subjective language that is my "good deal".

There is a school of thought that you should fuel up in the morning
because you will get more gas by volume than you will in the afternoon.
I'm sceptical about that one because the gas in the underground tank
probably has a much smaller temperature range than an exposed tank.

John Wentworth wrote:
"James" wrote in message news:turIg.2213
Gas expands and contracts a good deal with temperature change and it
increases the moisture in you tank when it "breathes".
How much do you think gasoline expands and contracts with temperature
change?
1% ? 10% ? .01% ? How much is a "good deal"? Please be clear on the
coefficient of thermal expansion for liquid gasoline versus gasoline vapors.