Someone told me that it's not good to ALWAYS run it, which i do.
Any truth to this?

 

I don't know if it will harm your engine in the long run, but you are probably not running very smooth right now.....our bikes are NOT made to take the 91 octane premium (i am assuming your premium is 91)...they are made to take regular 87 octane...there is a big thread on why it's not good to run the 91 and why running 87 is a LOT better, but i am too lazy to find the post...[&:]

EDIT: WHOOPS!!

 

Sounds like I need to go ahead and run all the preimium out of mine then and go cheap!!

 

In my experience...it doesnt matter.

 

agreed. If premium was 100+ octane then maybe it wouldn't fully combust, but 91 or 93 would most likely be fine. It just can be a waste of money.

 

What does matter is either going to Circle K or Shell.

 

Ugh... this topic gets kicked around more than a redheaded stepchild.

Page 91 in the 2007 Honda CBR 600rr owners manual... direct from the honda engineers themselves...

"Your engine is designed to use any premium gasoline that has a pump octane number of 91 and higher." (Bold for emphasis)

Not sure what bike you run... and it could be different. Hell, my owners manual for my Yamaha, if I recall correctly, states 89 or higher (and if it has too, it can even run leaded! Hell, to open a whole NOTHER can of worms, it also specificly states NOT to shift without the use of the clutch under any circumstances, up or down, and that, for the Yamaha, it could will cause damage to the transmission/engine) So read your manual for your bike, and, for me personally, I'll let everyone who thinks themselves to be a fuel-scientist 'cause they read something some guy wrote somewhere about some kind of fuel and whatever do whatever they want. The people who MADE the engine, the electronics, all of it, say use grade <blah> and up... I'm gonna stick too it. Seems smart enough to me. Hell, it's not like these things just guzzle gas anyways!

 

Do a search...

But long story short: Run the lowest Octane rating that will NOT cause pinging.

 

Page 87 in my '06 F4i manual simply states:

type: unleaded
pump octane number: 86 (or higher)

Honda recommends 86 octane for my F4i, but anything higher is ok (reading between the lines). Ofcourse, alot higher might result in detonation.

My $.02

Tommy

 

So more octane is for higher compression motors...
And my F4i has a CR of 12:1.
Most cars i've ever owned was ideally 10.5(ish):1. or lower.
Would that not mean i need better fuel? (assuming that petroleum companies wouldn't waste the money to make gas grade higher than most cars would need to run. I guess that's what makes or breaks this discussion.)


Not trying to argue and call anyone wrong, just doing my research to kepp my machine tip-top.

Edit: Tommy's backed by honda, i'll take his word for it and save me a few $$. Thanks for everyone's input. At least now i understand alot more than i did about octane and such.