[widebody911]

In order to be able to take advantage of higher octane, you have to have a computer controlled engine or an engine built for it. Extreme example: I could put avgas in my VW bus, and it wouldn't make one bit of difference with my 7:1 compression.

I run 100 in my 3.6L for track events, and it's happier that way. I can feel the difference between 100 and 91 consumer-grade pump gas.

The stuff sold at auto parts stores is complete crap; you'd be better off spending that 10-spot on a bottle of Techron.

If you're looking for an over-the-counter octane booster, a gallon of toluene or xylene (found in the paint aisle at your hardware store) would be more effective and more economical.