These tips may have made sense in 1973, they don’t apply now.
1. Tanks are insulated. They stay within a few degrees of the temperature the fuel was delivered at. I.E. Hot gas in the ground tank stays hot.
2. Nozzles these days must deliver the proper amount and they do reclaim fumes. That said how much more fumes are created between slow and fast? I’d bet it’s a whole pennies worth. It’s not worth the extra five minutes you’re going to spend at the gas station.
3. The bit about fuel evaporating because your tank is half full is bunk. All vehicles built in the past 20 years have sealed fuel systems. No fuel is lost to evaporation. The reason storage tanks have a floating lid is that gasoline fumes are extremely flammable, by having the floating lid, they minimize explosion risk.
4. Getting gas while it’s being filled is not harmful. All fuel pumps have filters on them. They look like your car filter and they will stop any contaminant from getting into your tank. Do you think any gas station wants to pay for repairs on cars they just fouled up? Ever heard of it happening?
About the only way you can prove it is if you buy gasoline at the same station every time. I have heard of people getting repairs done when the truck driver screws up and mixes diesel and gasoline tanks at the station.
No, and yes.
Back in the late '80s it happened to me.
I bought my gas at the same service station all the time. (Back then it actually WAS a SERVICE station with mechanic bays and everything.)
One day I stopped and filled up the tank and went to work. On the way home my vehicle just stopped running. I could wait 10 or 15 minutes and start it again, go for about 2 or 3 miles and it would quit again.
I finally made it to the service station, told them what it was doing, and walked the rest of the way home.
The next day they called and asked where I had filled up the day before.
I told them that I always filled up at their station.
I heard over the line an, "Oh $HIT!"
It turned out that the last delivery of gasoline they had received had water in it.
The water was collapsing my in-tank fuel sock.
They had to uninstall the fuel tank, open the tank, replace the sock, and reinstall the tank.
All at no charge to me.
This is one reason I always try to fill at the same station. If there IS a problem with the fuel they are more likely to believe a steady customer.
Gas station owners used to be clients of mine. It happens all the time. The main "rack", the big storage facilities, used to skim water and other impurities for their customers,but they pass it on these days. I saw a late model BMW unable to pull away from the pumps thanks to a bad lot of gas.
It happens, a lot; I can drive three miles from where I fix lawnmowers all summer and point out three stations that have sold gas containing water to over a dozen of my customers in the past five years.
They have all been cautioned to stay away from these guys.
The devices intended to isolate and minimize this problem require periodic maintenance and some places just don’t do it.
I used to own a gas station, one night our lot flooded over and we pumped over one thousand gallons the next day with contaminants and didn’t know it until the people came back with big problems.
I was also in charge of all the fuel and oil purchases for a V.A. hospital to power their equipment including power generators and I had my crew stick and water-test each tank every test run.
We routinely pumped out up to three inches of condensed water twice a year from our 18,000 gallon fiberglas new double walled tanks.
Never buy while or directly after the tanker is dropping fuel, period.
The state inspector here comes once each year or as soon as can be scheduled the following year and he always checks for water on the bottom of the tanks or in the delivery.
I keep a tube of water-finder paste in the garage all the time.