Hi there, I ride a 06 VTR250. Been filling it with 98 Octane all the time. But when I took my bike in for a check up the mechanic warned me against higher octane fuels...stating they contain additives designed for car engines and these silicon based lubricants and cleaning agents will clog up the carbs. So have I been possibly doing damage to my engine with 98 octane and throwing away more money while doing so? I've always avoided 91 Octane thinking the ethanol would be harmful to a bike....the latter being the fuel he recommended :s Any help would be much appreciated!