So my car is tuned for 94 octane with a can of boostsane octane, makes 20PSI. Took car in today to local mechanic and he was checking it out and we got talking about fuel. He told me I’m Better off running 91 octane cause after 91 all it is is ethanol blend to make it 94. I don’t plan on changing off 94 but does 91 actually run better than 91? Curious. Thanks.