What octane

[BusyWeb]

Sorry, Nuke..it
Double post, how to delete post???

 

[BusyWeb]

I think i do agree with you about the slight delay in throttle response with the higher octane. I thought i was imagining things and thought it must be in my head, sooo I'm glad to hear I'm not completely crazy!!

That's what I thought too for throttle response time... ha ha ha
Is it only me or my bike??? kind of thinking...

 

[tuningfork]

It could be possible that given the state of tune of your bike that one octane will work better than another. I would think this is most possible on a 2004-2006 given the open-loop nature of the FI system (AFR affects burn rate as well as timing and octane).

Additionally if the TPS is a bit off or something you might not get the true factory timing value, maybe a bit more or a bit less advance...in which case the octane may become a bigger factor.

Personally I'm staying with 87. :thumbup:

 

[Zanch]

It could be possible that given the state of tune of your bike that one octane will work better than another. I would think this is most possible on a 2004-2006 given the open-loop nature of the FI system (AFR affects burn rate as well as timing and octane).

Additionally if the TPS is a bit off or something you might not get the true factory timing value, maybe a bit more or a bit less advance...in which case the octane may become a bigger factor.

Personally I'm staying with 87. :thumbup:

87 for me too... no reason to go higher. Especially when the bike was made for 87. Only if you upped the compression, advanced the timings etc. would you need the higher octane fuel.

FYI... all that octane does is the higher the number the higher the temperature before it detonates. So if you're running a higher octane in something designed for 87 you're basically just wasting your money...

However if you're getting pre detonation (pinging) or excessive backfires (without chopping the throttle) go up in octane... otherwise don't worry about it.

With all that out... my YZ250 always gets 91 octane because it's a race bike and has higher compression. If I had an R6 or an R1 I would put 91 in too... why? because it's a race bike with race cams, higher compression etc. Part of the reason you buy an FZ6 is because you don't have to do all that other stuff, and it still does very well.

 

[Mancolt]

I remember reading a good article about higher octane. I was fortunate enough to read it before buying my bike. IIRC, it basically stated that higher octane ratings were usually achieved by adding ethanol to the fuel. This ups the octane, but as this thread has pointed out, ethanol sucks for our engines. So the added octane is not only not what's recommended by the user manual, but also achieves that by adding a chemical that isn't helpful for our machines...and it does so at a higher cost. I had always planned on filling up with 93 here in the states to take care of the beautiful motor, but that changed my mind. Now I save the $1 per fill up or whatever and just get 87 knowing that's what is best for the bike.

"Octane rating does not relate to the energy content of the fuel (see heating value). It is only a measure of the fuel's tendency to burn in a controlled manner, rather than exploding in an uncontrolled manner. Where octane is raised by blending in ethanol, energy content per volume is reduced.

It is possible for a fuel to have a Research Octane Number (RON) greater than 100, because iso-octane is not the most knock-resistant substance available. Racing fuels, AvGas, liquefied petroleum gas (LPG), and alcohol fuels such as methanol or ethanol may have octane ratings of 110 or significantly higher — ethanol's RON is 129 (116 MON, 122 AKI). Typical "octane booster" petrol additives include MTBE, ETBE, isooctane and toluene. Lead in the form of tetra-ethyl lead was once a common additive, but since the 1970s, its use in most of the industrialised world has been restricted, and its use is currently limited mostly to aviation gasoline." - Octane rating - Wikipedia, the free encyclopedia

I believe I read that in the U.S., one of the more inexpensive and common ways to raise the octane rating was to use ethanol (RON of 129) to boost the overall octane rating of the fuel being sold.

Another good read relating to this subject:
Understand Motorcycles & Fuel Octane Numbers

 

[yama4566]

What year fz6 are we looking at? I just took a glance at my '09 user manual and yamaha recommends nothing less than 91. However I believe when I bought my bike it just had 87 in it (dealer filled up the tank upon my purchase to get home) and I wouldn't imaging they put expensive 91 in for me but the bike ran fine. I feel like going back down to 87 for fuel economy reasons but I am a little hesitant to do so. ???

 

[DefyInertia]

I only run 110 octane race fuel...I get 75 mpg and make an extra 25 hp as a result. Oh yeah, the race fuel weighs less so my wet weight is down about 15 pounds too. I figure the small extra cost is worth it.

 

[tuningfork]

What year fz6 are we looking at? I just took a glance at my '09 user manual and yamaha recommends nothing less than 91. However I believe when I bought my bike it just had 87 in it (dealer filled up the tank upon my purchase to get home) and I wouldn't imaging they put expensive 91 in for me but the bike ran fine. I feel like going back down to 87 for fuel economy reasons but I am a little hesitant to do so. ???

Interesting, I wonder if they changed the stock ECU mapping, timing, etc. on the 2009?

 

[SirIsaac]

What year fz6 are we looking at? I just took a glance at my '09 user manual and yamaha recommends nothing less than 91.

How quick was that glance? My 2007 manual states the following on page 3-11 regarding octane requirements:

"Your Yamaha engine has been designed to use regular unleaded gasoline with a pump octane number [(R+M)/2] of 86 or higher, or a research octane number of 91 or higher."

The 91 octane requirement is based on it being a research octane number (RON). Did you see that number and interpret it as the pump octane number, or is 91 specified as the minmum (R+M)/2 octane in your manual?

I feel like going back down to 87 for fuel economy reasons but I am a little hesitant to do so. ???

If you mis-read your manual, my vote (which I follow every time I fill up my tank) would be to go down to 87.

 

[sxty8goats]

I have an odd question. I have been trying to answer this question for a while with the use of the internet with little success.

Due to the squish design and compression ratio, I think you're fine running regular.

Truth.. Octane is a combustion suppressor. It prevents pre-detonation in high compression engines. If you haven't changed the internals, you haven't increased compression. Yamaha recommends Regular, I use regular. There is actually more 'power' avaliable in lower octane fuels.

Personally, wouldn't run any of our bikes on anything less than 98, but I'm in Australia and I don't know what your highest octane level is.

The extra money is well worth it. Looks after the engine a lot better.

Good write up on Octane and Fuel in general.

Fuel and Octane - What is that all about? - The answer is here. - LS1GTO.com Forums

For what it is worth, in my GTO I run 87 in the winter and have had no problems with detonation. In the summer months I run 93.

 

[yama4566]

How quick was that glance? My 2007 manual states the following on page 3-11 regarding octane requirements:

"Your Yamaha engine has been designed to use regular unleaded gasoline with a pump octane number [(R+M)/2] of 86 or higher, or a research octane number of 91 or higher."

The 91 octane requirement is based on it being a research octane number (RON). Did you see that number and interpret it as the pump octane number, or is 91 specified as the minmum (R+M)/2 octane in your manual?



If you mis-read your manual, my vote (which I follow every time I fill up my tank) would be to go down to 87.

Pretty quick, I actualy looked at it again and it states exactly as you said so in the end 87 will do just fine. I'll keep this in mind next time I am at the pump. Thanks!

 

[thieu]

i only run 110 octane race fuel...i get 75 mpg and make an extra 25 hp as a result. Oh yeah, the race fuel weighs less so my wet weight is down about 15 pounds too. I figure the small extra cost is worth it.

your funnyyy!!!!!!

 

[Tree]

I find it interesting that the stock ecu mapping would be set up for low octane gas, I feel like better power and gas mileage could be achieved with a higher octane tune.

I mean really what do you save per fill up 80 cents?

 

[Bram]

In Belgium we have a choice between 95 and 98 octane.

I always use 98.

95 = 1.497€/liter
98 = 1.521€/liter

 

[cmor15]

What year fz6 are we looking at? I just took a glance at my '09 user manual and yamaha recommends nothing less than 91. However I believe when I bought my bike it just had 87 in it (dealer filled up the tank upon my purchase to get home) and I wouldn't imaging they put expensive 91 in for me but the bike ran fine. I feel like going back down to 87 for fuel economy reasons but I am a little hesitant to do so. ???

In my 2009 owners manual it says this:
"Your Yamaha engine has been designed to use regular unleaded gasoline with a pump octane number R+M/2 of 86 or higher, or a research octane number (RON) of 91 or higher."

In Europe they use RON only while in the US its R+M/2

 

[phranK2k11]

Octane rating

The most important characteristic of gasoline is its Research Octane Number (RON) or octane rating, which is a measure of how resistant gasoline is to premature detonation ( knocking). It is measured relative to a mixture of 2,2,4-trimethylpentane (an octane) and n- heptane. So an 87-octane gasoline has the same knock resistance as a mixture of 87% isooctane and 13% n-heptane.

There is another type of Octane, called "Motor Octane Number" (MON), which is a better measure of how the fuel behaves when under load. Its definition is also based on the mixture of isooctane and n-heptane that has the same performance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON.

In most countries (including all of Europe and Australia) the 'headline' octane that would be shown on the pump is the RON: but in the United States and some other countries the headline number is the average of the RON and the MON, sometimes called the "roaD Octane Number" or DON, or (R+M)/2. Because of the 10 point difference noted above this means that the octane in the United States will be about 5 points lower than the same fuel elsewhere: 87 octane fuel, the "normal" gasoline in the US and Canada, would be 92 in Europe.

 

[cookies]

All high performace vehicles should run the highest level of GAS pump octane, and according to yamaha our bikes need the highest available, it's not like in cars, for example a little 4 cyl eclipse that runs on unleaded gas MUST run on 87, it CAN run on 93 but it's not made for it, it wont work out well, on bikes, they are high preformace, and made to revv and love gas, so go with the highest possible AT A PUMP LEVEL!!!!! why do you keep wanting to put in 87, is that like the highest you have there?

 

[Red Wazp]

All high performace vehicles should run the highest level of GAS pump octane, and according to yamaha our bikes need the highest available, it's not like in cars, for example a little 4 cyl eclipse that runs on unleaded gas MUST run on 87, it CAN run on 93 but it's not made for it, it wont work out well, on bikes, they are high preformace, and made to revv and love gas, so go with the highest possible AT A PUMP LEVEL!!!!! why do you keep wanting to put in 87, is that like the highest you have there?

HUH? Yamaha says to run 87 octane, period. I have run 87 in my FJR1300 for 73,000 miles, FZ6 and FZ1 for 10,000 miles each and they run just fine. Actually higher octane is for anti knock and can be hard on motors that call for 87.
However I can tell you they do not run well on that 85 octane sh*t in Utah.