I have been using 87 octane in my tank since I bought my busa. While riding today a friend of mine who rides a busa said my bike sounds funny. I told him thats the way my bike has always run. After a long high speed run, we stopped at the Sunoco station. (I was running on fumes) I reached for my normal 87. He recommended that I should try the 93. I did. My bike sounds cleaner (It's really hard to describe it except to say cleaner...) But the throttle is what impressed me. My bike has more pep. My baby has always run, but she runs better (very obvious...) So my question is why??? I have read all the posts about waisting money using the 93. The bike is not optimized to handle 93... ...and that the manual recommends 87. I am here to tell ya my bike runs better using 93. This was obvious to my riding mates. My bike is stock except for the PCIIIusb and Yosh Carbon RS3 bolt-ons. My map is the Yosh bolt-on map from Dynojet...... What gives???