A fellow with whom I work used to be employed by an oil services & equipment company and he told me some interesting things about the business.
He worked on a pipeline at a pumping station and said that they would run XXX hundred thousand gallons of a certain brand (Exxon, Amoco, Chevron, etc.) through the pipeline at a time. It was a pipleline that served most of the Eastern Seabord of the USA and he explained how the stuff was pushed through the system.
When they changed over to another brand, there were several thousand gallons that might be a mixture of two brands as one was phased in and the other was phased out. That 'off-brand' stuff was then sold to the Zippy Mart, East Coast, Costco, BJs, 7-11, Kroger, discount or other non-branded fuel retailers. It might be ten thousand gallons of Mobil and Amoco mixed, but would still be decent stuff. Since the gasoline and the additive mix might not be 100% of one brand or the other, they could not sell it as "Exxon" or "Chevron" or whatever. {They wanted to keep the juice flowing, so they did not have a dry pipeline.}
Even so, all of the fuel still had to meet all EPA standards and different areas only a few miles apart might have different blend requirements. Blends even differ from summer to winter as well. In our area, Richmond and the surrounding counties require reformulated gasolines.....but Petersburg (20 miles south) does not; so prices are often 3 to 5 cents lower there.
Watch some of the oil tanker trucks that you see on the road. Very few even have a brand name on the side and you'll often see them make multiple stops in an area (as that is the most efficient way to do it). A single truck might drop 1000 gallons at an Exxon station and then drive down the street to a 7-11 and unload some more -- and may make a third delivery at a Kroger store where they sell gasoline. It all comes from the same tank farm.
There's probably a lot more to that business than any of us realize......but I don't think I have ever gotten a bad batch of gasoline but once or twice in 25 years of driving. I did get some bad diesel fuel for my work truck once, but that was probably because it had somehow gotten some water in it.
No matter what brand or grade of unleaded you use, consider pouring a bottle of fuel injector cleaner into your gas tank after every oil change. Also, avoid letting your tank get below 1/8 of the way full. That way, you'll have less concentration of sediment in the bottom of your fuel tank and a smaller chance of it ending up being sucked into your fuel line (and into your engine).
Okay, that's my two cents for the night.
