Having driven a fuel tanker for more than a few years, all this BS about top tier fuels is exactly that. I've delivered Sunoco, Marathon, Citgo, etc. to no name generics stations and delivered generic fuel to branded dealers as well. Generally unbranded dealers buy from whoever has the lowest price. Fuel companies trade fuel all the time.
In the late 70s early 80s I leased a Pennzoil service station, although there was a Pennzoil refinery within 60 miles of my station, and their gas was one of the best fuels in our area, there was also a bargain basement refinery (United Refinery) about 10 miles closer to me. 90% of the time my gas came from the crap refinery. United also had some service stations close to the Pennzoil refinery that they traded product to reduce shipping charges. I was a branded Pennzoil dealer selling the crap gasoline that came out of United refinery because the two refineries were saving a few dollars on shipping charges by trading product. The customers of the crap stations close to the Pennzoil refinery were getting a much better product/value for their money.
If it's a franchised dealer they likely will have a contract to buy through that brands jobber/wholesaler. In most every loading rack the fuel is coming from one pipeline shared amongst all the loading racks.
Fuel is graded by weight (specific gravity) restrictions, and as its loaded the additives are introduced into the fuel. There is no anti knock testing going on in each batch of fuel, just specific gravity tests. If you buy no additives you get ethanol and gasoline blended at the time of loading. If you buy a better (more expensive) blend you'll get detergents added at the time of loading. Same gasoline, same ethanol.
I buy unbranded fuel all the time for my own use, never had one problem due to fuel quality in my own vehicles, diesel and gasoline. If it were my own car, I'd buy the 93 non ethanol unbranded and sleep just fine.
When you've been around fuel racks. service stations, and refineries for a good part of your life you find out the little nuances that oil companies do to save a penny here or there, much like the auto industry cheapening parts and pieces to save a nickel and it ends up ruining their reputation. I.E. GMs 6.2 LS engine debacle, among other GM mistakes that the book keepers thought looked good on paper. Mistakes, (intentional or accidental) in fuel blending are much more forgiving than not polishing crankshafts in engines before assembly.
