I have ben told many times that Chevron with Techroline is the best. Who knows if this is right? Moving from dallas texas to norman oklahoma one of the things I noticed was that 91 octane is highest sold in central oklahoma. I had always used 93 in dallas, was a little unnerved at the 91. But after using it for a couple years I have to admit that I haven't noticed a difference. I still go back to Dallas once a month (regular poker game), and even the occasional 93 tank doesn't show any difference.