Let's take a look:
Someone posted on Facebook yesterday that it's best to fill up your tank early in the morning or when the temperature is cooler. This person said gasoline expands in warmer weather and it contracts in cooler weather so in cooler weather you get more for your money. So I did some checking.
It needs to be noted that you don't get better gas mileage.
One of the sites I checked said gas expanded perhaps 1 to 2 percent so if you put $40.00 worth in your tank, it's like saving 40 to 80 cents per fill up. Fuel pumps are not required to be corrected in the United States except in Hawaii. Most northern states voluntarity correct their pumps to allow for the colder weather. It benefits them to do so.
This also brings to mind that it's good not to top off your tank because as it gets warmer, your tank could overflow. It also brings to mind the safety question of portable gasoline cans and tanks. The expansion occurs there too, especially if they're in a hot garage.
So fill up on a hot day and you're losing money.
Conclusion: Fact
