It's not even a dollar a tank more, why are people so cheep.
The motor has 12 to 1 compression and needs the best gas
you can get.

 

^+1

 

^+2....my 02 f4i says minimum 91 octane on the sticker on the tail subframe?

 

I always run 91+ in my bike. since i bought my bike in the fall i never got a chance to check my mpg what does you guys get with the f4i?

 

Its been a few months since this thread has come up so I'll go over it again.

The compression and ignition curve are designed with 87 octane in mind. Octane is a value for how much heat is required to get the fuel to ignite. You use the lowest octane gas you can to properly keep pre-ignition [detonation] in check. Anything more then whats required and now the flame front doesn't propagate correctly and you have un-burned fuel going out the exhaust instead of contributing to cylinder pressure. As we all know un-burned/overly rich mixtures cause carbon to form much quicker which builds up on the piston and to a less extent the cylinder head. Eventually if the build up gets bad enough it can cause hot spots and detonation and now you've screwed yourself into requiring that higher octane until you clean the engine out not to mention the plugs will foul quicker as will the oil.
And it says 87 in the owners manual. One sticker is europian octane rating, the manual is america style octane rating.

 

I have a hard time believing super is going to build carbon faster than regular lol.
Justify your thriftyness. It's ok ill still fill on premium thanks.

 

I am still amazed as to how many people want to do the best for their bike, yet do not understand this. The bike is designed on 87, it wants 87. There is people who will only put Honda Coolant in, or Honda Oil, but when it comes to fuel, they don't put in what Honda says.

 

The manual says 87....So if Honda says to use 87, Im using 87.

 

I've always run 93+ since I got the bike. the one time I put 92 in (because it needed fuel & that was the highest offered at that station) the bike ran like crap! I know the manual recommends 87...but after what happened when I ran 92 in it, I've been afraid to try 87. I might have to give it a shot for a couple tanks, I've been told it'll start easier...not that it's hard to start.

 

The thread seems to have strayed away from the original question of how much premium fuel do you actually get when the previous customer may have used regular and the hose still has that in it.

As far as what octane to use the rule of thumb is to use whatever the owner's manual recommends unless you've changed the timing or raised the compression ratio. My manual says minimum 91 octane.