That makes some sense NMR. I really wish I could use the other gasolines but the problem I have is that both of my cars do not run good at all unless I put Chevron or Shell/Texaco gas in them. My van sputters and runs rough when I fill up at other stations and my Honda goes through oil like water through a sieve if I use other stations to full up. Now, my daughters older Honda will run the same on any gas she puts in.
I did not believe it myself until I switched back and forth and what it just further proved my experience.
All the companies fill up at the same refineries, it is the additives added that make the difference.