I usually run a tank of 93 octane mixed with the 87 grade, 1/2 & 1/2 and have never had any fuel issues or "cold stumbling" that some have reported...Almost 9000 miles so far except for an occasional shot of Seafoam, all seems to be okay...Have tried the higher octane on occasion and noticed no difference between it and the 87 octane...Always use Mobil or BP as I have credit cards with them. Personally, I don't think it makes much difference how much of the previous customers fuel choice is left in the hose...JMHO...Ride safe