I understand that but I refuse to run gas that has ethenol in it and up here anything other than premium has ethenol.OK, for a modded (higher compression) engine it may be required.
Keep in mind if you are looking for the best performance from an engine (like you must be) just running the highest octane gas available is costing you power. You want the lowest octane level that just barely holds-off detonation.
Many moderately tuned race engines will produce more power on pump gas than a high octane race gas, but because the "spec gas" is required they all have to use it.
You need to run the modded engine on a dyno with different fuels to know what is best. Higher isn't better. Proper octane fuel is a simple way to get all of the potential power from a modified engine.