I've used nothing but premium (91 oct) in my last three bikes. The Vulcan I had to because of the performance upgrades, the ST just seemed to like it better, and I stuck with it in the Wing. The size of the fuel tank and the mileage of bikes it doesn't cause me to much $ increase versus the gains in performance and consistant fuel grades (seems to be less fluctuation in quality with the premium grade). I don't use ethanol based fuels either if I can avoid them and their running issues. Be careful if you use ethanol fuels, they can de-stabilize in as little as 3 weeks and are very prone to water (ethanol has water in it) separation/contamination/absorbtion. Ethanol based fuels are poison to two-stroke engines for that reason; I know Wings are not two-strokes lol. So for those of you who ride snowmobiles or older dirt bikes be wary. Water injestion will kill your sled or dirt bike in a heart-beat if improperly protected/set-up.