What octane fuel do you run in your FJ09?

[dbeau]

Here in California the difference between mid-grade and premium (89 vs 91) is usually ten cents. For a four gallon fill-up that's 40 cents. Why not run the best you can get? I have 26,000 trouble free miles on my FJ-09 and always put premium in.

You understand that "Premium" gas is not "better" than "Mid-Grade" or "Regular", right? 
 
 

[OutlanderBC]

95% of my fill-ups are 91 (without Ethanol)
 
But depending on where I travel I've put regular 87, 91, 94 and honestly I haven't noticed any difference either way.

[suitedsevens]

91 octane all day. It boggles my mind you guys would run anything less and save what $1 a tank at most? Farkle out the bike and then pinch pennies at the pump, uh huh makes total sense. Manual calls for high octane as it is a high compression engine, no brainer for me.

[2and3cylinders]

Definitely do not want a war over dollars and sense (pun intended). Each to their own.
 
I run premium 100% of the time but for & giggles I may "test" as objectively as possible within reasonable limits of effort and readily discernible differences in "performance" ("measurement scale taking into account optimal operational parameters like under higher ambient temperatures and speeds with and without minimal air cooling beyond just slow, heavy traffic, like a heavy right wrist, etc) if for any other reason to have a good idea if it's "safe" to run regular and mid-grade when premium is just NOT available.
 
I presume we all know that each grade is offered for its relative anti-knock attributes not its octane per se; i.e., not for increased "performance" (HP/TQ)
 
It has been long borne out that efficiency has nothing to do with needing or not needing more octane, and tests on regular gas ICEs show more uniform operating efficiency with the lowest grade the mega-thermal mass dead dinosaur it can fire without popping.

[koth442]

MFA (local good gas, never any ethonal added). 91 octane.

[eeetea]

Not so much increased power or anything like that, but the premium fuels in the UK have engine cleaners detergents as additive.
 
In this electronic day and age sticking different grade fuel in. The engine will just retune itself to suit, so you won't witness anything. Stick it on a dyno and you will, but for normal day to day riding it makes sweet Fanny Adams difference..other than the cleaners.

[krupted]

So far I've 91Octane in the FJ09 save for once.  Usually it's Shell, Esso(Exxon), or Petro Canada.  Only did a weird remote fillup once, and used 89 since that was the highest they had.
 
I'm thinking of going down to mid-grade (89) now, from what I'm reading here.  if that goes well for a while perhaps down to regular (87).
 
In my KLR I had to use 89 even though it only called for 87, or it'd start to pre-detonate under load or in hot weather.  I suspect I had carbon deposits in the cylinder.
 

[dundee]

As said in this forum, "premium" adds octane to reduce detonation (fuel exploding before it should in the compression cycle). Detonation will be most pronounced in the summer when higher engine temperatures are encountered, especially when idling.  I mainly use 87 octane and during the summer occasionally 89 octane.  I have also used premium (91 - 93 octane depending on station).  I have seen no difference in performance or fuel economy with any of the grades.  My Yamaha dealer also uses regular 87 octane fuel and told me before I purchased my FJ-09 that premium wasn't needed.   The energy content in BTUs and additives, other than octane, are the same in all fuel grades.  Premium does not "burn cleaner" or have more energy content.  If you experience pre-detonation with 87 or 89, YES you should use premium.   If your bike, like mine, runs fine on 87 or 89, then there is no benefit to burning premium.  In the US, keep in mind also that there are some states (such as New Mexico or Colorado) where the typical available fuel grades don't even include the normal 87-89-91 octane levels.   In Colorado, regular is 85 octane due to the elevation and historical norms.  Mid-grade in Colorado is 87 octane.  I would not use any chemicals on or in my bike that would harm it.  

[YamaGeezer]

I'm in North Georgia and run 93 octane BP. When I slack off riding in the winter I switch to non-ethanol and 90 octane is the highest grade available. Never had any detonation and it's plenty warm here in the summertime.
 
Ride Safe -

[budviking]

Is the Shell 91 free of ethanol?

[kiwicanuck]

Is the Shell 91 free of ethanol?

 
 
Here in Canada shell 91 is ethanol free

[koth442]

Is the Shell 91 free of ethanol?

Depends on where you're at. In California, no. Other places, like the aforementioned Canada, yes.

[lefty80883]

87 octane and always from a tier 1 station. 35k and no issues.

[skipperT]

As said in this forum, "premium" adds octane to reduce detonation (fuel exploding before it should in the compression cycle). Detonation will be most pronounced in the summer when higher engine temperatures are encountered, especially when idling.  I mainly use 87 octane and during the summer occasionally 89 octane.  I have also used premium (91 - 93 octane depending on station).  I have seen no difference in performance or fuel economy with any of the grades.  My Yamaha dealer also uses regular 87 octane fuel and told me before I purchased my FJ-09 that premium wasn't needed.   The energy content in BTUs and additives, other than octane, are the same in all fuel grades.  Premium does not "burn cleaner" or have more energy content.  If you experience pre-detonation with 87 or 89, YES you should use premium.   If your bike, like mine, runs fine on 87 or 89, then there is no benefit to burning premium.  In the US, keep in mind also that there are some states (such as New Mexico or Colorado) where the typical available fuel grades don't even include the normal 87-89-91 octane levels.   In Colorado, regular is 85 octane due to the elevation and historical norms.  Mid-grade in Colorado is 87 octane.  I would not use any chemicals on or in my bike that would harm it.  

 
 
While I agree with most of this, I disagree with your “burning cleaner” statement.
 
Lower octane fuel DOES NOT burn as cleanly as 91 - in the sense that a lower octane gas leaves more carbon deposits behind on the valve stems and piston crowns - then higher octane gas.
 
It might have nothing to do with the actual octane content - but more to do with the fact that (if it’s quality, name brand gas) it’s mixed and refined with better chemicals then lower octane fuel.
 
I’ve torn similar engines apart that have used both types of fuel - and the higher octane fuel leaves less carbon and other crap behind then the lower octane.
 
Alternatively, run Ring-free. It’s amazing stuff.
 
-Skip

[keithu]

Most of the time I burn 91 (AKI) E10 from a Chevron because it happens to be right on the way to work. I try to stick with 90-91 octane because I'm hung up on Yamaha's recommendation.
 
But I've run 87 a few times when in rural areas and that was the only thing available. I noticed exactly zero difference in how the bike ran.
 
Like Betoney said, ethanol-free fuel is dear and hard to find in the PNW. Seems like a waste of time and money with a modern vehicle like the FJ.