octane????
Being born in Houston, TX, around the refineries, I saw trucks of every brand from the majors to the minors filling at the same spigot. Probably the additives are the difference.
Just my two cents.
Oh, yea, I now burn the cheap stuff. After 15K miles, I've tried the 'good' stuff when first got the bike new... can find no measurable difference.
Can't make it run on water though.