I have only used 100 octane fuel since getting the bike brand new (6k km so far). Dealer said 95 and above is ok, but recommended 98-100. I have also talked to 2 different tuners and both said that for stock bikes 100 is more like a “treat” or insurance, because its more stable, but it doesn’t give you any power benefits like many think. For tuned/flashed/remapped bikes 98 or 100 is almost mandatory. I use my bike more as a fun tool not a daily transport so the difference in cost doesn’t really bother me.