93 or 100 octane

[lexuspilot]

If your engine was retarding it's timing because of insufficient octane(knocking), then adding a higher octane would increase power.

The question might be "Where you really buying the 91 octane you thought you were buying?"

Sorry, but using the butt dyno means using butt logic not labratory logic. The very long post above lays the ground work to assume that you have been buying crappy 91 only to then try excellent 100. My money would say there is a power difference in that case.