I'm not sure how much that really matters anymore. I rarely see the big brand tankers running the interstate like I did years ago. I prefer to use ethanol-free in our motorhome (GM 454) and have stopped at several of these stations between Florida and the Carolina's. I've never had a problem. My rule is to make sure the station is near a river or lake so it gets plenty of trailer boat traffic to keep the gas fresh.
Across the river from me are several gasoline tank farms (Hess and BP). I see tankers loading up and delivering to Shell, Texaco and our local independent (Gate). I was told once that the fuel was the same, but different retailers just added their own "brand specific extras" to it.
Maybe that's how every station in a given area has the same price per gallon.
That said, I still prefer to buy from the name brand/high volume dealers to insure fresh fuel (and clean facilities).
