I put premium in all of my machines. Aw, just a few cents more for so few gallons. Why? Because the premium holds its octane value longer and does not degrade as quickly as "cheap" stuff. Also, sometimes I don't ride one machine or another for a few months, and the premium is less likely to be degraded. Also, we still have frauds on the market, big and small. It's harder to cheat on premium because an engine that requires premium will let you know loudly when you're feeding it crap, OR, as in my BMW, it will power down.