[mobythevan]

Higher octane does mean the gas burns slower and is harder to ignite, but.... that means you can run higher compression engines which have a higher efficieny and get more useable power out of a gallon of gas. There is nothing bad about higher octane fuel unless the engine its run in is designed for lower octane, then it doesn't get you anything. However, if the engine is designed with higher compression and only runs higher octane you get a higher efficiency engine and more power per gallon of gas. This is where E85 shines with its 105+ octane rating. I built an engine specifically for E85 and it has 12.5:1 static compression. I use to get 27 mpg with the factory compression of 7.8:1 and 85 octane pump gas, I now get 24mpg on E85 with the high compression. Much better than the typical loss of 34% to switch to E85. I got about 18mpg with E85 and the 7.8:1 compression, more in line with the 34% loss. Your arguements and ideas are very good, but other factors come into play with higher octane.