My owners manual clearly lists the octane requirements for my 1999 225's and meeting that requirement is no problem when we trailer boat. On extended trips in water it is often difficult to find options other than just reg gas and diesel. Should extended running on 87 octane be a problem? Will the knock sensor control detonation to the point where I need not worry or is the compression high enough where this will result in detonation? My experience so far with this has been with the German electronic controls which can detune the advance timing enough to compensate for regular gas.