i dont wanna be a jerk but
91oct in a N/A with regular compression ratios will give you absolutly no performance gain in fact it does the opposite The octane rating is a measure of the autoignition resistance of gasoline and other fuels used in spark-ignition internal combustion engines. It is a measure of anti-detonation of a gasoline or fuel. so the higher the octaine raiting the less your N/A will perform. on the other hand it will get you better mileage and burn cleaner just thought you should have some facts