I'm aware of that refinery tidbit but perhaps others aren't. Local tuners know which brand is best for power and if one needs more volume for the same power. i.e. which additive package has the most knock resistance and energy. Ask, they will have an opinion. Locally, Texaco WAS preferred in 93. Texaco left the market and premium went from 93 to 91. Yep, the local refineries stopped making 93. Now 93 comes from another island, is carried by a few independents and is triple the price of 91. But when tested it comes in at over 94 octane. Anyone have an opinion on oxygenated fuels showing leaner AFR's at WOT? Off topic, gotta stop myself. I've put every brand of gas in some car sometime during my life. Correct octane, not enough and too much. Use what's recommended unless you've tuned your car for more is my position. I've never damaged an engine driving day to day with less than recommended octane but the marbles in the motor sound was menacing.

Les