Fill up in the morning? Myth busted, plausible, confirmed?

[aalb1]

Yes yes yes... another one of these threads... with a TWIST!

We all have heard the myth that if you fill up in the morning you fill up with denser fuel than if you were to fill up in the afternoon after it had all day to heat up, expand, and lose density.

Now the Myth Busted argument is that it isn't affected at all b/c the fuel is stored underground where the temps doesn't fluctuate as much.

But here's the twist: Costco is going to adjust "temperature adjusting pumps" in some of their gas stations. Here is the article!

So if there is enough reason for a lawsuit to be created, and the industry to start installing temperature adjusting pumps... might this myth be plausible or furthermore confirmed after all?