I run 93 octane in my truck because it keeps the valves from making a lot of noise when the engine is under load.
Anybody want to know what octane is and why it matters? Gasoline is made up of octane and heptane. It's just the length of the hydrocarbon molecule- same atoms, slightly longer chain in the octane. Octane is more stable and is not as susceptible to pre-detonation due to pressure in the cylinder. Higher octane rating, less pre-detonation. At least according to Dad (chemist) and dad's wife (long time Vetco Gray employee).
I think the real difference is in the additives. The gasoline marketing people realized that they could set their product apart using additives. Basically everybody gets the same stuff off the pipelines from refineries. They put their own additives into it before it gets sent to a Chevron/Exxon/BP station for resale to us. The best detergents, etc get added into the high end stuff, unless I've been lied to.