76 was the best, followed by Texaco or Chevron, (forgot which) and then another brand. I don't know what kind of tests they performed but from personal experience of using Chevron for YEARS, when I gave a few tanks of 76 to my car, it seemed to have run smoother. 76 is all I put in my car now followed by Chevron as a last choice.
"Be kind, for everyone you meet is fighting a harder battle" ~ Plato