A higher octane fuel does not mean more power. As a fluid is compressed, (yes, air is considered a fluid) it's temperature increasses. The octane rating of a fuel is basicly a mesure of it's flash point, the temperature that it ignites. The mixture heats up as it is compressed and the spark ignites it at a point that it will make a slow, even burn, gradually increasing cylinder pressure as the piston rounds TDC, and expanding pushing the piston through the power stroke. To low of an octane fuel can cause preignition, when the fuel combusts from compression before the spark, causing high cylinder temperatures and ruining your exhaust valve as the superheated gasses exit (and in extreem conditions, I've seen it, turning a motor backwards), or detonation, when the spark ignites the mixture in a sudden, violent explosion causing extreem, destructive force on the piston (imagine hitting it with a hammer rather than pushing it down with your hand). Using a higher octane fuel does not change to BTU rating of the fuel, so power remains the same. It simply changes the temp at wich it will ignite allowing it to burn evenly in a higher compression or hotter running motor. I hope that this answers your question and saves you a few bucks at the pump, FlatForOne. Everyone else, sorry for the textbook but he asked to be schooled.