Filling up when the tanker truck is delivering

Factual Questions
1

I’ve heard that it’s not a good idea to fillup at a gas station when they are getting a delivery from the tanker truck. Something about the turbulence stirring up sediment that could get into your gas tank. Any truth to this?

2

I have heard this as well, and generally try to avoid filling up when the truck’s there for just this reason. But on further reflection it would seem that they’ve GOT to have filters in the pumps, right? Otherwise we’d all have pounds of crud floating around in our gas tanks by now and clogging up our fuel filters, wouldn’t we?

OTOH maybe the refining and transporting process really is pretty clean and the amounts of junk are miniscule.

3

I heard because it stirs up the water which has condensed one the inside of the underground tank and now rests at the bottom of the tank (the gas floats on top of the water).

Gas stations test their tanks (with a very long stick having a substance smeared on the end that changes color when it contacts water, they can tell the level of water at the bottom of the tank) and periodically pump out the water.

What’s the Dope? “Crud” or water?

4
      • Both: crud does get stirred up that is small enough to make it through the pump filter, and the bottom gasoline can be saturated with water (where I am, IL/USA).
  • Previous to mandated alcohol content, the water (being heavier than gasoline) would collect more or less at the bottom of the tank, and the first few suckers to roll up afterwards would get a few gallons of water into their cars. Now the water gets absorbed into the gasoline mostly so it doesn’t detect on the stick as well, but water-saturated gasoline is heavier than normal, so it still collects at the bottom of the gas station’s tank.
  • How does the water get into the gasoline at the fuel distributor? —I dunno, but it does. I doubt it’s intentional on the part of the fuel distributor, because most modern cars will barely run on watered gas, if they run at all. Many stations now have electronic setups that read tank levels and have sensors at the bottom of the tank to monitor water content; they only manually stick the tanks once every week or two. - MC