The computer can offset the ignition timing for lower octane as well as higher- The atmospherics have a big effect on things and my understanding is above 4000 ft- it is a waste to use high octane fuel...Being I live at 6200 in the winter I use 87 and redline fuel system cleaner to keep things good, and change my fuel filter on a winter summer rotation- Below 4000 I rock as high as I can because of the beneficial atmospheric conditions. On other threads there have been discussion of toulene (octane booster), among other things. On the higher compressin set up likes the blowers I think it makes sense- Also given the stuff is 10-12 bucks a gallon it makes sense to get a 55 gallon drum of VP race juice. I myself am cool with pump gas. I have found 76 gas station fuel to work well in my car, so I am fairly loyal to using that- good luck.