Originally Posted by RidingDonkeys
Yeah, I probably should have worded that better. Higher octane fuel burns slower and is less affected by higher temperatures. Any pre-ignition is going to make an engine run hotter. Hence why I tend to run premium in summer, where traffic and temperatures alone can be bitch on an air cooled engine. I don't typically any signs of preignition, but I also don't want to take the chance if I'm on a long ride in the summer.
I do the same. Yesterday I filled up with 87, but I can get away with that in cool temperatures. In the summer, I get a fair amount of run-on if I don't run higher octane.