Premium or Regular......07 Attak

[Mongo 1]

In New York we have the R+M method, so I use 87. Ron is higher than Mon, so if your pump states Mon you could use a lower number then 91. Hope that helps.

 

[Blue Dave]

I use 87 whenever I can get it. It is available at most every "gas station", however when you are filling up at bars & resorts on the trail sometimes all you can get is 91 or higher.

I have not been able to detect any difference in performance and I do not care about or even check my mileage so for me it is just about not spending more money if I do not have to.

 

[yamaha1973]

87 is fine, no need to pay more for premium

 

[Reverse]

OK, so I've got a "10 Apex with power commander, ig. mod, yamacharger, clutched, geared etc. (ignition timing retarded 10 degrees). Engine compression remains the same of course. 87 or 91 best????

 

[Super Sled]

OK, so I've got a "10 Apex with power commander, ig. mod, yamacharger, clutched, geared etc. (ignition timing retarded 10 degrees). Engine compression remains the same of course. 87 or 91 best????

Depends on if your programmed your pciii that your sled will be running on 91 or 87. I have seperate maps for each.

 

[Reverse]

Allan sent me the pc pre programmed. Do I call him or can I check myself??

 

[blue er]

i use 91 in my apex for the no ethanol reason only.
example when a friend with a 10 vector and i did a rap tour last year we were both filled with 87 the vec got better mileage as expected, after finishing the 87 started to fill with 91 ethanol free, every gas stop after that it was pretty much even my fuel bill about the same (penny's difference) but i took less fuel, guessing it is more btu available without alcohol in premium fuel that makes the diff over octane.
and this has been repeatable over and over again in fuel mileage tests on my sled against the vector.
also i use 91 just for the simple fact i never know how long between rides and don't want to be bothered with the problems of phase seperation doesn't matter what you put in the tank and ethanol is still a solvent

 

[Blue Dave]

OK, so I've got a "10 Apex with power commander, ig. mod, yamacharger, clutched, geared etc. (ignition timing retarded 10 degrees). Engine compression remains the same of course. 87 or 91 best????

What is the advantage of retarding the ignition timing by 10 degrees?

 

[pharsyd]

Ok, after rereading the posts, and contacting yamaha canada, talking to a product specialist, this was the respponse i got. Manual and Sled in two spots reads to use RON91 MINIMUM. I do know the difference between now between the two. Lsat night i looked at the pumps, and here in Ontario (R+M/2), 87, 89 uses 10% ethanol, 91 or higher none.... When speaking to the poduct specialist, he immediatelhy told me that the minimum is 91RON, which is 87, but is a true believer in avoiding ethanol. Being 91RON is the minimum, he highly recommended using the 91 R+M/2. He said the computer (efi?) will adjust to the change in octane, but will perform much cleaner and stabile at 91. Some coutries which the sleds go have higher octane ratings compared to the R+M/2 upwards of 97 and perform well. He has heard more negative reports of 87 M+R/2 from the mechanics over the last couple of years with things mentioned before of it not burning as clean and ethanol for canada 87 R+M/2 ...... So, I think i will stick to his highly recommended 91 here in ontario, and avoid the ethanol altogether.

 

[Mongo 1]

guessing it is more btu available without alcohol in premium fuel that makes the diff over octane.

Yes the ethanol will lower the BTU of your fuel, typically you see a loss of 1 to 2 mpg on the blend. I use e-85 in my Suburban and lose 3 to 4 mpg over regular.

In New York we can't find ethanol free gas many places anymore, even the premium has it now. My attak doesn't mind it but every carburetor I looked at this year has had serious problems, even with "good" stabilizer.

 

[wndoguy]

I am in Ontario also, and have been running 91 in my RX1 as well. Not for the Octane, but for the lack of ethanal. I recently found a station selling all octanes WITHOUT ETHANOL in Orillia. I will be buying 87 from now on from there, for all my stuff.

My brother inlaw runs 91 in his Polaris, and his engine is always running hot. I wonder if the higher octance has done this to him?

 

[UP Michigan rider]

engine is always running hot

If its running hot, it could be running very lean, or he has a high compression engine. If he has a high compression engine, and not a high enough Octane, the gas will explode when it is not supposed to. Octane itself would not = heat however

 

[UP Michigan rider]

Let me add one more thing, if he has ethanol in his fuel, ethanol has the effect of adding more oxygen to the air fuel mixture and thus would cause the fuel mixture to run even MORE lean than it might already be thus adding more heat. I would stay away from ethanol especially if you have an already lean mixture due to the environmental laws etc.

The environmental laws are ruining engines in more ways then one.

 

[UP Michigan rider]

Bump

Just a bump for the new year.

 

[Blue Dave]

OK, so I've got a "10 Apex with power commander, ig. mod, yamacharger, clutched, geared etc. (ignition timing retarded 10 degrees). Engine compression remains the same of course. 87 or 91 best????

Why did you retard your timing 10 degrees?