patton, I blew by your first reply.
Underground tanks are at a constant ~65 degrees, just about everywhere, I think...
Fuel delivered to tank farms is usually at or near 50 degrees and the temperature of the underground tanks varies from near 60 - 85 degrees in central Texas. That was one thing I hated having to do, was to lower a brass thermometer into the tank and have to wait a certain amount of time to get the fuel temp. You had about 10 seconds to record the temps, once the gas hit the outside air.
Gasoline expands quite a bit in higher temps. We had gasoline in an underground tank hit right at 40 degrees after a delivery in 1986 when the outside temps stayed in the single digits for more than one day.
"Gasoline expands quite a bit in higher temps"Dating myself, I used to fly on these and remember an 0700 takeoff time where the fuel tanks were filled in the early AM hours, flying out of Otis AFB, on Cape Cod. When we got on board, we looked at the wings, and fuel was POURING out of the tanks due to expansion in the sunshine as they had filled them fully in the cool morning hours, and it was expanding....
Ground crews came and siphoned off fuel to remove excess and make expansion space available.
Yes, fuel (including gasoline) really can expand quite a bit!
