I fluctuate between the gas that I use.  I am a jobber for wholesale gasoline.  I will use two sometime three tanks of Regular or 87 octane gas, then one tank of a higher octane.  You guys have it right for the most part without getting super technical into the properties of the octane ratings.  The biggest difference in the types of fuels are the additives.  A high octane 93 fuel is going to have many difference additives that prevent the engine knock and sorts like that.  The higher octane’s also clean the engine better than lower octane’s.  The studies done by my suppliers show split block engines that run an 87 octane gas on one side and a premium 93 on the other.  The difference can truly be seen using a borascope (spelling?) to look at the valve heads and inner engine parts.  But this is really just food for thought.  Everything that I have done with my bike says it runs just fine on 87 octane.  I am like many others and "treat" her every few tanks to a nice dinner.  The single cylinder seems to have no problems with lower octane fuels.  


John
Middle GA

Ethanol is a different story...
Check out the ethanol post  


http://suzukisavage.com/cgi-bin/YaBB.pl?num=1240360601

BORESCOPE
http://en.wikipedia.org/wiki/Borescope

Octane relates to preignition...the fuel and air charge inside the combustion chamber firing before the spark fires, or being started by the spark but burning too fast causing spark knock.  Yes, the speed the gasoline & air mixture burns is important.  Backfire or afterfire has different causes.