Somebody once told me it's a bad idea to leave high octance fuel over the winter(Im pretty sure person who told me was making a point about Sunoco/Petro's Ultra 94). He never did provide a reason as to why this was. Can anyone shed light on this? My 07 zzr600 states right on the tank 91 and over, so I figure by putting the 94 in all the time I was doin the bike a favor.