We don't have a 7-11 for many, many miles away
that I know of anyway
I haven't been to a 7-11 in 2 decades
I was using Shell or Chevron 89 or 91 exclusively
it runs the best in my stuff up here
& my Granddad (Shell 44 years) & uncle Ron (Chevron 40 years)
both were engineers for oil co.'s
I did prefer the either Union 76 or Shell gas, back in the day
we have no Union 76 up here, haven't seen one in years either
they both said the same thing, some years ago, as sort of said above
it's just basic gas, in the pipelines & is all mixed/blended together
& the either the individual jobber suppliers, to the stations
&/or Shells or Chevrons distribution suppliers &/or tankers/transporters
add/mix in the additives that Chevron & Shell specs out,
at their distribution hubs, before it goes to the station
some of the stations aren't Shell or Chevron, just no names too
the Phillips & BP stuff 'sucks ***',
my truck (99 Dakota with a tune & various bolt-ons) doesn't like it
"at all"