cool well thanks for answering my question and some lol, it says run 91 on my bike but iv been putting premium (93) in it for close to a month now and havent noticed any diff, but thanks for the info, deff didnt know any of that lol i know some one said 87? the guy i bought the bike from told me not to put 87 cause it would run like **** i figured that was true cause i put 89 in my Mach One, one time and it calls for 93 min and it ran like total ****

Running a higher octane is fine, running a lower octane can cause pre detonation and engine knock and mess your stuff up. You wont notice a difference between 91 and 93 but running 87 in an engine designed for 91 could definitely cause issues so stick to 91+ octane.

cool alright, but running 93 as to running 91 wont help me nor hurt me more either way? one just cost more than the other lol

I mixed you up w/ LilRed F3 and his post asking about an F3, you can run 87 in an f4i. My owners manual says 86 or higher (pump octane), so if you wanna run a higher octane you can.

correct.

and yeah are we still talking about f4is? if thats the case you can just run 87 like chambers said. If the previous owner said your f4i runs like **** on 87 then its the bike, not the gas....or he just didnt know what he was talking about. The rr's or at least the 07+ rr's i think call for 91 but the f4i manual says 87 so stick with that unless you dont mind paying more for higher octane gas thatll give you no benefits compared to regular.

I already have the service manual, I couldn't find information on octane requirement or compression ratio. Yes or no, can I use 87 octane? Is 87 the minimum requirement octane? A lot of questions that have probably already been answered, but I'm still a fresh noob.

87s the lowest recommended yes.

^Thank you.

Dude if your still asking about F3's then go to the F3 forum and ask there. This is the F4i forum, we know about F4i's not F3's.

02trickflowGT- the sticker on the F4i saying use 91 octane is misleading. Its actually a different rated 91 octane then the way we rate octane here in america. As stated above the manual calls for 87 octane which is what you should go by.

Indeed, here in the UK we get 95 and 98 RON at most pumps, it is near on impossible to find less than 95 or more than 98 and there are only a handful of vehicles that NEED 98, everything else runs on 95.

There are three gradings, MON, RON and PON. MON gives a better idea of the octane in a working motor than RON and so gives out lower numbers. PON is what the USA list fuels as, this is the average of MON and RON. Europe use RON because it sounds better to sell fuel with higher numbers.

95 RON is roughly equivalent to about 91 PON that US pumps sell. My bike (F4i) runs on 95RON. We don't sell an equivalent of 87 PON in most petrol stations.