Now that you've brought up the possibility that Techron or something similar may be in other gasolines besides Chevron, this brings up the issue of gasolines in general. Over the years I've noticed that my car just plain seems to prefer certain brands, and I think that the preference is related to additive packages. Here is an informal listing of "good" gasolines, in my opinion.
By the way, I always run 93 octane, based on the "cleaner fuel" theory--remember the Amoco Ultimate commercial a few years ago that showed the beaker full of black gunk that regular gas has in it that gives the amber color? I was doing this long before the Amoco commercial, as my old Festiva (bought new in '88) simply did not like regular. I got 350,000 miles out of that car and one experienced mechanic told me that he thought running the higher octane made a difference (cleanliness). The old thing loved Amoco Ultimate: it ran better and seemed to gain a few hp, surprisingly enough. And with less than 60 hp on tap, a couple extra horses made a difference. Even with my '97 Escort wagon I see differences in how this more powerful car runs and drives depending on the fuel I use.
Anyway, here's the good gas list in my order of preference:
Sunoco (no stations really close to me, but I'm on the road a lot and have used its 93 octane many times with excellent results)
Phillips 66 (rare here, but one station is relatively close)
Chevron
Texaco
Amoco (had a bad tankful of Ultimate last year, killed an O2 sensor, so I've been cautious since)
Pennzoil (tried it one time out of my area; good results)
Here's my "iffy" gas list. I'll use these if nothing else is available. Again, my opinion.
Citgo
Shell (though Shell should now be the same as Texaco, it isn't always around here)
Here's my list of fuels that I avoid at all costs. Again, my opinion. Even if running on fumes, I'll keep driving to avoid their use:
Exxon (had more than one bad tank from different stations, and even on a good day my cars haven't cared for its premium)
Mobil (same fuel as Exxon anyway)
Convenience store brands (certain of these, especially one chain based in Pennsylvania, have a really bad reputation)
The question I have is how the additive packages might have enhanced--or not--the fuel. And note that Chevron is on my good list. Your comments would be interesting.