91 octain fuel

[SilverFox1]

Stripperking!! That's exactly what I was going to write! Well done sir. I believe everything you just said. It's been decades since I've peeked at my books but just the same, I know what you're talking about is the truth.

SilverFox

[cjackg]

That is a very helpful description of the Spyder fuel / octane reqmts.
Can you elaborate some on how things are affected by using Ethanol 10% vs pure (non-Ethanol) fuel ?

[Barbary]

Just make sure everyone is aware of the difference between the RS and RT. The RT does run a higher compression ratio than that of the GS/RS and that is why BRP recomends higher octain for the RT. The RT is 12.2:1 and the RS is 10.8:1. Octain slows burn rate and is harder to ignite, compression increases burn rate and makes fuel easier to ignite. Lower compression will run better on lower octain and higher compression will run better on higher octain. There are some very complicated mathmatical formulas for all of this. The objet is to get the fuel ignition point at the desired piston location and the burn duration for a desired length of piston stroke. High compression and high outdoor temps mixed with city stop and go traffic is a bad mix for high compressin engines (12.2:1). If your engine pre-detinates you may not really know just how much but trust me your engine does.
Fact, high octain fuel in a low compression engine is a waste of $ and will probably rob HP. What happens is the burn rate slows to a point where the fuel does not all burn through the desired piston range. This is not the desired condition. By the way low is in the 8`s, low 9`s.
Fact, low octain fuel in a high compression engine does not create max efficiency. The higher compression causes fuel to burn faster (faster flash rate) so the fuel will be all used up before the desired piston range has completed leaving a dead zone in the stroke. High comp. at least in my oppinion is about 12.5:1 and above. 10.8:1 is somewhere in the middle so no you probably can not tell one grade from another. If you have an RT as some of you have noticed, you should be able to tell 87 from 93. Right now it is cool so not as big of a deal. This summer when it is hot as @#$% it is a bigger deal.
Just incase some may not know why low octain is so bad for high compression here is a short explanation. All modern engines ignite fuel before the piston reaches full compression or the top of the stroke (TDC) so that the max flash point can occur just as the piston starts its down stroke. If you use fuels that flash to fast you will reach this peak before the piston is at the top of its stroke. This wastes some of the fuels efficiency and literally tries to shove the piston backwards (pre-ignition).

There is way more to this but I made it as simple as I could. Bottom line BRP makes the recomendation for higher octain in the RT for a reason, not just to suck $ out of your pocket. Hope this helps.

PS: I know my spelling is bad but hope it`s not so bad you couldn`t read it.

so what ur saying is me putting that square block in the round circle, altho i made it fit, wasn't a good thing...

[StriperKing]

That is a very helpful description of the Spyder fuel / octane reqmts.
Can you elaborate some on how things are affected by using Ethanol 10% vs pure (non-Ethanol) fuel ?

Ethanol robs power from conventional fuel plain and simple.

[ridesilver2009]

Check out www.pure-gas.org. Add your pure gas station to this site.
With the help of the info, I haven't had to use any of my Startron, Sta-Bil Marine Formula of Yamaha additives.

[capt.jim]

Today i was at the dealer and noticed a new RSS and the sticker said 91 oct., what has changed between my 08 GS rated for 87 oct. and the new ones, aren't they both 10.8 compression? I occasionally run 91 but can't tell any difference from the 87. About the only place you can get nonethanol in Fl. is at the marinas, and it's about $4.50-$5.50 a Gal.,but the ethanol is a killer for outboard engines that sit for more than a few weeks at a time, such as mine since the spyder came along, especially the carburated motors, and the plastic and rubber parts. They are talking about bumping the ethanol up to 15% here

[ThreeWheels]

Where the heck are you guys getting 91 Octane gas ??

All the gas stations I frequent have either 87, 89, or 93.

[granpa in Cincy]

Ethanol robs power from conventional fuel plain and simple.

And now the damned fools plan to raise it to 15% from 10%.

I cannot agree that it is wise to use food for fuel.

[dancogan]

EU ratings are 95/98, which are equivalent to US ratings of 91/93.

EU 95 octane = US 91 octane and EU 98 octane = US 93 octane

RON: Reaserch Octane Number in EU
MON: Motor Octane Number.
AKI: Anti-Knock Index. This is the number that is posted on the gas station in the USA as "Octane"= (RON + MON)/2

Thanks for the clarification.

[Bob Denman]

And now the damned fools plan to raise it to 15% from 10%.

I cannot agree that it is wise to use food for fuel.

I think that the ethanol is made from by-products... whatever's left over after they get done making creamed corn for us!

[boborgera]

I think that the ethanol is made from by-products... whatever's left over after they get done making creamed corn for us!

If it were just by products that won't be so wrong, But there using whole corn. Before the ethanol nonsense started i was buying whole corn at 6/8 dollars a hundred, Now it's more like 16/18 dollars a hundred.

[RAL]

Lets see.... Overall more energy is actually used to provide the same amount of work, it take materials that should used to feed human beings away causing that price to go up as well as adding to the hunger burden globally and it shortens the life of vehicles...meaning more resources and energy will be used to produce more vehicles....round and round each factor compounding the others...compounding...compounding...... on and on
At best its a scheme to make a few rich...who knows but its effect is 180% out from the "claimed " goals


RAL

[NancysToy]

Lets see.... Overall more energy is actually used to provide the same amount of work, it take materials that should used to feed human beings away causing that price to go up as well as adding to the hunger burden globally and it shortens the life of vehicles...meaning more resources and energy will be used to produce more vehicles....round and round each factor compounding the others...compounding...compounding...... on and on
At best its a scheme to make a few rich...who knows but its effect is 180% out from the "claimed " goals


RAL

Well said!

[Marker]

And now the damned fools plan to raise it to 15% from 10%.

I cannot agree that it is wise to use food for fuel.

[Marker]

Lets see.... Overall more energy is actually used to provide the same amount of work, it take materials that should used to feed human beings away causing that price to go up as well as adding to the hunger burden globally and it shortens the life of vehicles...meaning more resources and energy will be used to produce more vehicles....round and round each factor compounding the others...compounding...compounding...... on and on
At best its a scheme to make a few rich...who knows but its effect is 180% out from the "claimed " goals


RAL

Well said

[cjackg]

Where the heck are you guys getting 91 Octane gas ??

All the gas stations I frequent have either 87, 89, or 93.

How's this for variety... There is a Smile Gas station on E.Brainerd Rd in Chattanooga TN that sells Non-Ethanol Gas in all of the following grades, all at the same pump: 93 92 90 89 87 !

[spyryder]

How's this for variety... There is a Smile Gas station on E.Brainerd Rd in Chattanooga TN that sells Non-Ethanol Gas in all of the following grades, all at the same pump: 93 92 90 89 87 !

That pump likely has a 'blend' valve:
http://science.howstuffworks.com/eng.../gas-pump4.htm

[boborgera]

Where the heck are you guys getting 91 Octane gas ??

All the gas stations I frequent have either 87, 89, or 93.

Sunoco in Jersey among others. I avoid the numbers game and only use 93.

[cjackg]

That pump likely has a 'blend' valve:
http://science.howstuffworks.com/eng.../gas-pump4.htm

"Octane Cocktail" Aint it wonderful !
It just keeps getting better & better...

[woodchuck]

Put 5 gallons of 91 octain fuel in my RTS other day and bike really seemed to run a lot smoother and it felt comfortable putting along in high gear at 4000rpms with two up which it has not been able to do since I have bought it. Last fill up used 89 grade not as smooth but better then 87 grade.Seems most on this board use 87 octain. Looks like i will have to stay at least 89 grade. Milage seems the same (29.4) no matter what fuel grade. Have others found the above true or am I the only nut in the group. JW Miller

Back in the 60's which was a long time ago Amaco had a white gas that we ran in our bikes. It would run a lot better and more power. What the octane was I don't know. But it boosted power.

[boborgera]

Back in the 60's which was a long time ago Amaco had a white gas that we ran in our bikes. It would run a lot better and more power. What the octane was I don't know. But it boosted power.

Remember it well, It was the only pump gas with out lead.
So campers would use it to cook with, and for lanterns in tents.
Also sparkplugs would last for ever, The problem was it cost 4/5 cents more a Gal, Back in the 50's/60's that was like your right arm.

[Euripedes Neves]

Scotty..

As to MPG.. I only get 25 with a high side of 27 average Regardless of solo, solo with trailer, with teacher, or with teacher and trailer.

I was using 91 as the book calls for.. I have in the past two weeks changed to 87.

I found no difference in mileage nor performace. The engine sounds and runs the same.

My measurement of MPG is riding on expressways 90% at 70-75 mph. Rpm's being 5500-5800.

Yes... Wheeler will state I got 32 mpg once. However, we did not exceed 45 mpg for almost 80 miles and I did not leave 4th gear.. This has not been repeated ( 32 mpg ) since.

I use 89 and i have got 30 to 36 mlg going less 60mph, if i go on the interestat 70 to 80mph i get 30mpg. w/ my trailer loaded i get 28mpg. I got 25K mls, and i am very happy.

[woodchuck]

Put 5 gallons of 91 octain fuel in my RTS other day and bike really seemed to run a lot smoother and it felt comfortable putting along in high gear at 4000rpms with two up which it has not been able to do since I have bought it. Last fill up used 89 grade not as smooth but better then 87 grade.Seems most on this board use 87 octain. Looks like i will have to stay at least 89 grade. Milage seems the same (29.4) no matter what fuel grade. Have others found the above true or am I the only nut in the group. JW Miller

I am confused on why one has to run such a high octane in the new spyder.(91)
According to what I read, my 09 spyder has 106 horsepower and I run 87 octane.
The new spyder only has 100 horsepower. The only difference is the throttle boby is smaller. Same engine.

[boborgera]

I am confused on why one has to run such a high octane in the new spyder.(91)
According to what I read, my 09 spyder has 106 horsepower and I run 87 octane.
The new spyder only has 100 horsepower. The only difference is the throttle boby is smaller. Same engine.

The new Spyder has a higher compression ratio.