an dont burn 91 octane gas in an engine designed for 87 octane...
Obviously you know not of what you speak. Higher octane gasoline does NOT provide higher energy output on combustion. High performance engines burn high octane gas for one reason ........ to prevent pre-ignition (detonation, or spark knock) which will destroy a high compression engine in short notice. Some racers don't even know this, but it is a fact that engine builders know well.
If a parallel exists between shotgun barrels and internal combustion engines it is not what you propose.
