Don,
I am not a chemist but most of what he said I agree with. I have always used the low setting to fill up as I don't want to waste gas by having it splash back and some of the hoses up here don't shut off like they should. I also go in the mornings as I don't like the crowds and heat in the afternoon, but I do know that heat causes gas to expand. I was getting ready to go to town one day a Summer or so ago and I had filled my car the morning before. I pulled it out into the driveway and the temp was around 112 degrees. I went out about 20 minutes later and gas was coming out around the cap. When it was cool you couldn't even see the gas with a flashlight. I know because since the car was new my gas gage has never read above 3/4ths of a tank and I just never drained the tank and had a look at it, so I fill the car until the pump shuts off and then look into the neck to see if I see gas.
Ron
