First off, I didn't take time to do a search for this. So my service manual has conflicting info in it, on one page it says I need to run 91 octane minimum but later it states I need to run 87 minimum. I know it's only a few pennies difference in the grand scheme of things but... I figured I don't need the higher octane since I don't believe the stock evo is a high compression engine. Any thoughts?

 

Sorry guys, I'm going to re post in the fuel section, I couldn't figure out how to just delete the thread.

 

I run 87 most of the time. When it gets up around a 100 deg. here in Kansa I run 89 just to make sure it does not pre ignite. That is in my carbed 99 EVO.

 

I'm pretty sure my owner's manual states to use 91, which is what I usually put in. Just to see if there was a difference in running 89 I've tried that a few times. The bike seems to run just as good as with the higher octane.

 

I run 87 when the temps allow it and I've never heard my engine complain. Could proably run it when it gets hotter out but, as you said, it's only a few pennies difference and I'd rather play on the safe side.

 

I run 90 ethanol free. No problems.

 

I run 93 octane 100% gas in my EVO. I can feel more vibrations with the 87 octane fuel.

 

I do the highest octane, since it clatters with lesser grades.

 

. From what I've been told, the 883 sporty is the only Harley you can run regular in. Harley says all the others require premium.

 

I get the highest octane I can, usually 91 around here. I figure the little bit extra I'll pay for 5 gallons of gas is worth it for something I have put a lot of money into already.