On the west coast we have 91, when you go to states that have 93 at pump do you use it or stick with 91. Im sure that most of you have your bike tuned to what ever you have locally and I know 93 wont hurt just wondering.
In Canada, at least in Ontario, it's 91 except for one brand that has 94. If thats my only choice I use it and seem to have less pinging and a bit more power. Same results when I go through the states on the east coast with the 93. Sooooo, i'm fine with it.
I just go with the highest octane at the station i`m at. Usually in the 90`s but there was some out west that was only 87. I don`t worry about it really.
The motor will like the lowest octane you can run without detonation. I run 87 and/or 89 in my 107" '02 carbed FLHT at 10.4 static CR; 87 in the cooler months and 89 in July-August. The motor likes it, runs a tad bit cooler and mileage improves, not much but 1-2 mpg on average.
We have 93 available here as well as 91. Main reason for always using the 93 is that it has it's own dedicated nozzle at the pump. 91 shares a nozzle with the lower octane fuels that are blended. When you use a shared nozzle, you are getting whatever is still in the pump hose etc so some portion of your purchase is actually the cheapest stuff that the vehicle ahead of you bought.