We often drive up to Brookings or Goldbeach for a weekend git away several times a year.
I have done many DYNO runs in fact 2 years ago I did a total of 99 in one year. The local muffler shop did (now it is not legal in CA don't ask) car shows and often asks me to run the DYNO. I owned at one time a convention floor mounted Chassis DYNO ,portable DYNO and engine Dyno, so I am at least sorta experienced with using them. And I am very OCD about setting up the base line programming so the runs are very accurate and I can repeat the perimeters "DELTA" for comparisons of engine changes. I never really paid attention to much to what anyone used for fuel besides most of them were "spiking" the fuel with octane boosters to get better DYNO printouts or that "selfee" next to the DYNO Monitor with their top numbers. But what fuel used was always a conversation and I still seem to hear Union 76, Shell and Chevron as the top fuels used. While I am sure their were CostCo, BP and Sinclair fuel users I doubt with that crowd anyone was going to admit using it. LOL With my automotive industry business associates all over the US and a couple other countries , ASE informational , All DATA updates and information ,TSBs, etc and a few other periodicals most of us have mentioned minor diviability issue cleared up by simply suggesting to our customer to use Chevron or Shell predominantly. While I can't say on this subject none of us ever did proper testing to say with any facts the true outcome to using strictly those fuels I can say at least for one platform most all service dealership as well independent shops that service the BMW/MINI most all recomend to use Chevron fuels.
When I race brackets and use Chevron running a specif gravity test and times having to use Shell or other fuels I did find that Chevron tested a little more predictable. But using other fuels never showed in my average ET's running handicapped racing. so I never gave it to much thought. In the Explorer I will use whatever fuels,the MINI's only Chevron,the PT mostly, Safeway fuels which could be anything,except when I race and then only Chevron with a little bit of xylene. shhhhh!
The S/G Camaro when I was still professionally NHRA class racing I only used 76 or Socal Race fuel. All the motorcycles either 76 or Chevron except the RG which I ran a custom mix of fuel. So although it may seem like my loyalties was favoring Chevron I do use other fuels.
Oh the MAZDA only Chevron...unless while traveling can not get it. And then I always carry a small bottle of my own cocktail of fuel additive to add to the tank to get by until I can fill back up with Chevron.
You know it funny but no one mention how the spark plugs like different fuels. but I won't start that conversation on this forum. I already looked at a few dozen threads and responses and there is a lot of "tribal wisdom" concerning what spark plugs to use and how long they can last between changes....wow!!! LOL Not one member mentioned doing any proper spark plug testing to even find the best spark plug gap let alone running the engine on an oscilloscope to see what the ignition system was doing with the chosen spark plugs and choice of gap? LOL