Just don't buy premium gas at some out of the way station where no one in town has a turbo car. Then only half a tank. Many cars now use premium so the odds are in your favor. No real need to worry about that half gallon or less that will come out as regular. American Petroleum Institute says about 1/3 of a gallon is in the system so no real worries. But it is cool to look for the proper situation. I never bother though. But, as you have experienced, I was on a cross country trip on my K13S. We were in the middle of no where back east and could only get regular 87 octane. Bikes were dogs. The next gas station was a Conoco and we got some 94 octane. Could now pass cars while in 6th gear. It was like a switch had been flipped. Chevron gas in Canada has 94 also. Have not seen that stuff on the West Coast. Don't let people tell you it makes no difference, it does. (do not go down the road of comparing EU fuel ratings against USA, they are different numbers)
Mount Vernon, WA.
tire guy, I'll mount your tires.