Hi guys/gals,

This is one of my first posts on this site. Two month ago, I bought an 04 F4i which I absolutely love. It's my first bike & riding season, and I've been taking it really easy since. This bike is so fast; it's like learning how to drive with an Enzo. I've taken the MSC and have put almost 2,000kms on the bike so far - and loved every minute of it.

Anyway, I had a question regarding octane. I thought this bike requires premium fuel and only filled it up with 91-octane gas. However, reading the owner's manual today, I saw that the bike requires a minimum 86-octane.Do you folks fill-up with regular gas, or premium?

I'd hate to spend the extra $ on higher-grade octane fuel when it's really not required, and from what I read in the manual, it seems like it isn't.

Thanks very much!

 

Im in a similar boat with regard to it being a new bike for me as well. Yes, the manual says 86 and you will find alot of people here do in fact use 87 octane. Others prefer 89 as its kind of middle-ground as far as knock control and price.

As the manual says, you may hear detonation if your gas isnt up to the bike's standards. I would say run a tank of 87 through and if you hear knock, then up the octane to 89. As you said, no reason to use 93 if you can get away with 87. Knock can be heard as among other noises, a popping sound at higher rpms. You will also notice a loss in power during the detonation (detonation and knock are synonymous)

My bike came with a Power Commander and therefore I think I might need to continue using 93 as it might well be mapped for that. Ill have to wait and see.

 

Seems simple enough.

 

What about with a Power Commander in place?

 

Surely does. Yet I wonder why my guy @ the local tune shop says I should put 91 in it, as well as other random riders I come across?

 

go with what u want to pay and then if youve got engine work done (not a pcIII) but actuall engine work. other than that if your gonna tear it up and go all out then get some race fuel like 110 leaded youll notice a diff, but everyday to and from dirivng get what u can afford, it wont hurt you bike putting 87 in it. since gas around here is 4.25 for premium im sticking to mid since its only like 3.85, hope this helps

 

you don't need to run higher than the lowest grade recommended unless you are:
1. tuned for it (pc3r, etc....regular pc3 will not require it unless you have a custom map running on the lean side).
2. internal engine work.
3. you are pinging because the gas sucks wherever you're at.

 

Great, thanks guys. My bike is bone stock!

I just filled it up with 87 and will keep doing so unless I hear pinging. I guess that, with the engine exposed (compared to a car), if it does happen, it will be obvious and I will hear it?

I drive my bike pretty slow, and she almost never sees the last half of the RPM range...

 

Yes, you'll know it when you hear it. I doubt it'll ever happen unless you're riding uphill in 2nd gear at 65 mph towing a trailer.

 

I just switched from 92 (which I have been using for no particular reason) to 87 with no discernable difference what-so-ever.