My Owner's Manual for my 2005 883-Custom, which I recently bought used, says to use 87 octane. Is it better to use a higher octane such as 89 or 93 octane? I don't mind paying more if it is advantageous to do so.

Thanks guys. I always appreciate your advice.

 

i always use 93 octane in everything i got. some say that using a higher octane when not called for actually reduces power. as for me, i cant see it hurtin anything but can feel more power. i dont really know an advantage for using a lower grade fuel.

another example is, a more common fuel has to be replenished more often. this stirs up everything at the bottom of the tank, water trash and other debris. im a commercial truck driver and get all kinds of trash in my fuel all the time, due to the constant refueling of the tanks. just for me, the added piece of mind that my 93 octane fuel might have a little extra time to settle out all the deris is well worth the extra cents.

 

proper octane choice is based on engine compression ratio for the most part. lower compression ratios for bikes from 8-9.5 to 1 ratio will run best on 87-89 octane. Higher compression ratios from 9.5 and higher will run best with 93 or the highest availabe octane available. Some areas you may find race/airplane fuel which is most commonly 110 octane. THe main concept of what higher octane levels will do for an engine is provide a more stable even burn at higher under higher compression. Low octane gas under too high of a compression ratio becomes unstable and will predetonate and in severe cases start a deiseling effect by firing from the compression alone. And in the other case high octane gas in a low compresion engine may not have full burn resulting in less power and wasted fuel. But at the same time at high RPMS can also lead to higher than normal compression, which in the case of a race bike, even a race bike with a low compression engine, it may need higher octane fuel when under high rpm's to prevent predetonation.

Many of the 883's are in the 9 to 1 compression area and will run perfect on 87 octane, and most of the 1200's Ive scene are stock around 9.5-10 to 1 compression and will run better with higher octane fuel, especially under hard acceleration.

Simply put if your bike runs good on 87, then don't waste your money, but if you get engine pinging under hard accelleration, then give higher octane fuel a shot, simply see what runs better for your bike. Just keep in mind that just because it's called premium gas, doesn't simply mean that it's better quality gas, it just depends on your engine's compression and how you use your engine.

 

now that is one heck of an explaination lol good job bro that tought me alot and i didnt make the thread lol if i can i have one question though, in my case where i run 93 in everything, could you call in extra insurance againt predetonation and/or uneven fuel burn?

 

i don't know if i would call it insurance against issues......you can have other opposite problems as well going to high a octane in some cases......like delayed firing.......although the issues are general less severe in the too high octane case, so you'd most likely just have less efficient fuel burn and less power as the main problem to worry about. Predetonation is a more severe problem as it puts a lot of stress on engine components, but if you have it happening it's ussually pretty easy to spot from the pinging knocking sounds, and also the looke of the spark plug can give you signs of fuel burn issues.

 

I recently had a run through Maine. I tried premium (92 octane) and found an immediate power loss. Tried two tank fulls before I switched back to 87 octane. I found an immediate increase in power. I will stick with this from now on. 04 883 custom.

 

Thanks for those great responses....I knew I could count on you guys for the answers! I had no idea about the relationship between engine compression ratios and octane.

Looks like I'll use 87 octane after all.

Thanks!!!