Octane rating does not correspond to energy contained per gallon. In fact, lower octane fuel has MORE energy per gallon than the more refined high octane fuel. This is due to the longer, more complex mollecular chains in less refined fuel. Unless an engine NEEDS the ignition related characteristics of high octane fuel, there will be absolutely no power or efficiency advantage to be gained by burning high test. Just more $$$ for the marketing guys at Oil Co., Inc.

This high power-myth about high octane gas sure dies hard!