Octane is the resistance to burn so you don't get preignition or detonation. I usually run midgrade. Which comes out to 89 octane I believe. According to the oem manual it says run 87 octane and if you experience knocking or pinging then put a higher grade in it. In F4i's it is a waste of money to run premium if you aren't experiencing knocking or pinging. I would start at regular unleaded if you start to experience knocking or pinging then bump it up to midgrade. A little bit of knocking and pinging for the time being won't be a problem, it's if it keeps occuring for long periods of time do you start to do internal damage.

 

umm i doubt running a higher octane is gonna make your bike "lose" power. People dont pay more for better gas to get more power, if anything it's just running cleaner.

 

You will not lose any power by running a higher octane fuel. As per higher octane fuels being cleaner or even "Name Brand" fuels being cleaner, I dont really think so. To answer the original question, I found out recently that I have a VP Racing gas station a couple blocks away from my house.(Good for my turbo charged DSM) They sell 100 and 93octane fuel out of the pump. I've run 100 and 93 with absoulutelynodifference except theamazing smell that 100octane puts off, it shouldbe a colonge, equivalent to sex panther.Iusually run 91 (standard premium in the great state ofNevada)andno problems with it, butI'm going togo with 87 ifI dont get any knock with it.

 

GENERAL RULE...go lowest without knocking...if it does...then go up.

now as for higher octane producing less power...we would really need to see a dyno comparison of a bike that doesn't ping at 87...and then runs 91...and compare...common sense would say that there is no power to be gained (bike has dumb ecu, no sensors telling it to advance timing or back off timing, etc.)...but as far as losing power...i guess it is possible if you go super high octane and the fuel doesn't burn completely.

100 octane does smell great...i don't know about a cologne, cause since chicks don't dig the smell, you'll just be attracting guys...hahahhahaha...

 

I thought this thread was about him asking what the owners manual says to run...

 

manual says a minimum of 86 octane. just checked mine

 

Everyone is talking about this possibility of a knock with the 87. If its not bad to run the 93, and you get no knock, then why not do it. Think about it, were only talking about a few gallons here. At my gas station, the 93 is about .20 cents more a gallonthan the 87, so to fill it up what are we talking about....one dollar? As long as the 93 is ok to run, ill stick with that and pay the extra dollar, besides i dont have to worry about, or listen for any knocks.

 

I have never had any kcocking or pinging on 87....just so you know there is a downfall, I don't know how much you loose, but by running the higher octain, you are loosing power.....

 

lol im not saying running higher octane or anythign cuz it doesnt make a difference but if you put higher octane in there it doesnt make you loose power. i ran 110 leaded in mine and dynoed it and showed a 3hp increase over the regualr gas so i beg to differ and wish i still had my damn sheet to prove it but you will not loose power by running a higher octane. are engine are made to run on 87 but are also made to run on race gas hence improving the overall performance of the engine. ima get it re tuned and dynoed again after i get my header and will save the damn slip of regular to a higher octane gas

 

Ok fair enough, but you are also comparing a bike that has been tuned....not sure what all is done during the tuning, but if something as little as spark advance is messed with you no longer can compair...the more octain, usally the further you can advance the spark. Run a lower octain with an adavnced spark and you get knock. The higher the octain the slower and cooler the fuel burns....that is all I am saying....