91 octane or better?

[fredz43]

is everyone following the manual and running 91 octane or higher?

If not, any problems?

 

[~TABASCO~]

Im sure my dealer filled the tank with 87.... seams to run fine.. Ill try 93 next time just to see if the motor acts different...

 

[retro]

I've only been running premium so far, I'm a little worried about 11 to 1 compression and no knock sensor on low octane fuel.

Retro

 

[~TABASCO~]

I've only been running premium so far, I'm a little worried about 11 to 1 compression and no knock sensor on low octane fuel.

Retro

I agree... Has anyone used a bit of octane booster.... Here is my problem.. 99% of our gas stations have one nozzle and 3-4 grades of gas... The person in front of me PROBABALY bought 87... How many gallons am I pumping in the tank of 87 before the system changes it over to 93... I might be paying for 5-6 gallons of 93 and only getting 2-3-4 gal...... This sux... I want the whole tank 93... Just cuz im particular and strange...

 

[adventorider76]

I like using premium in my bikes. At around $1.20 more a tank it really isn't that much more money. Just my 2cents worth.

 

[sportrider]

Dealer told me he put 87 in the tank. Didn't notice any difference during break in from 87 to the next two tanks of 91.

 

[Twitch]

I agree... Has anyone used a bit of octane booster.... Here is my problem.. 99% of our gas stations have one nozzle and 3-4 grades of gas... The person in front of me PROBABALY bought 87... How many gallons am I pumping in the tank of 87 before the system changes it over to 93... I might be paying for 5-6 gallons of 93 and only getting 2-3-4 gal...... This sux... I want the whole tank 93... Just cuz im particular and strange...

I always wondered about this. It would seem inequitable that if you’re only buying a small number of higher octane gallons and half or so are a lower octane. The other thing I’m curious about is the effects of ethanol on the octane level and smaller engines in general. I’ve read that it has a nominal impact on the octane, but I’m not sure I believe what I’m reading on that. I saw an AMA alert a week or so ago that the government (U.S.) wants to increase the maximum ethanol to 15%, and in it they said that ethanol is destroying smaller engines. Anyone have any thoughts on if higher impending ethanol levels are going to be a problem in these engines? There are additives out there to offset the effects.

 

[hANNAbONE]

I did a Friday run to Iowa city and back the long way.
I put +300 miles.on her and started with the 91 I had in there.
I had to.fill with 87.
I just put back in 91 again.
I felt there was a difference,, especially just off idle...coming.from.a.stop..first gear.
If the 91 fixed only that it would be worth it.

 

[colorider]

I felt there was a difference,, especially just off idle...coming.from.a.stop..first gear.
If the 91 fixed only that it would be worth it.

I'm thinking there will be a difference, especially at lower elevations.

 

[Checkswrecks]

...99% of our gas stations have one nozzle and 3-4 grades of gas... The person in front of me PROBABALY bought 87... How many gallons am I pumping in the tank of 87 before the system changes it over to 93... I might be paying for 5-6 gallons of 93 and only getting 2-3-4 gal.....

It's a problem for general aviation and really small gas tanks, like scooters, but we don't need to worry with our cars or motorcycles. The EPA requires pumps to have a built in vapor recovery system and those are designed to also draw the fuel back down to the tank. I've heard the calibration guys talk about leaving from a cup to a half gallon in the hose.


So if there's a half gallon for worst case and we typically refill our 6 gallon tanks with 4.5 gallon of fuel...
.5 / 4.5 = 11% of the refill will be the lower octane.
So rather than 93 octane, if the last guy used 87, you get 92.34
And again, this is worst case.


The alcohol content affects you more than that.


btw - For small airplanes we may have a 20+ foot long hose and no vapor recovery system, so there may be 2+ gallons of residual. Each grade gets it's own pump.


Checks

 

[jajpko]

I agree... Has anyone used a bit of octane booster.... Here is my problem.. 99% of our gas stations have one nozzle and 3-4 grades of gas... The person in front of me PROBABALY bought 87... How many gallons am I pumping in the tank of 87 before the system changes it over to 93... I might be paying for 5-6 gallons of 93 and only getting 2-3-4 gal...... This sux... I want the whole tank 93... Just cuz im particular and strange...

I read about this somewhere, and the article said you are only getting what is in the hose. That would only be a quart at best, I would think.

 

[~TABASCO~]

Very good !! Thanks for the info !

 

[tomatocity]

My dealer fills with 91 octane. Got 35 MPG @ 97 miles when I refilled. I did not notice the sticker on the tank until I finished filling with 87. Filled again @ 212 and got 48 MPG. It was too new for me to tell about performance. I did not hear any pinging and most of those miles were in the mountains between 3,000-8,000 el ft.

I don't know why but the performance feels better since 800 miles. This thing is a Torque Monster.

 

[keeponriding]

Dealer didn't fill it....maybe 2 gallons when I picked it up.

I've run 93 octane since; After 700 miles, I'm pegging 45 mpg on average...that's 80% 2 lane, with a lot of twisty's.

No pinging and no sluggishness, but I've also been keeping below 4k on the revs.

 

[markjenn]

Some of you are being overly paranoid.

First, the residual gas left in the hose with most gas dispensing systems isn't that much - typically a few oz at most. This is something that is tested by state agencies as part of the pump certification process.

Second, ethanol has much higher octane than gasoline, around 100 pump octane. In fact, ethanol is considered an octane enhancer that raises the overall octane of the gasoline/ethanol mix more than you'd get by simple proportions. Now the refiners take advantage of this and may use a lower-octane base gasoline in E10 to achieve their desired octane rating. Regardless, if the pump says 91, then the mix should be 91 or better.

Fill your bike with 91 or better and you're extremely unlikely to have any problems. If you need to throw some lower-octane in now and then because you can't find 91, that's probably Okay too, but I'd back out of the throttle if you hear anything that sounds like pinging. Even an engine rated for 91 is unlikely to ping on lower grades except in the most demanding conditions which are hot weather, big throttle openings, low RPM, and heavy loads.

- Mark

 

[Twitch]

Second, ethanol has much higher octane than gasoline, around 100 pump octane. In fact, ethanol is considered an octane enhancer that raises the overall octane of the gasoline/ethanol mix more than you'd get by simple proportions. Now the refiners take advantage of this and may use a lower-octane base gasoline in E10 to achieve their desired octane rating. Regardless, if the pump says 91, then the mix should be 91 or better.

Thanks, that was the answer I was looking for. Wasn’t trying to appear paranoid; I just didn’t know.

 

[colorider]

Second, ethanol has much higher octane than gasoline, around 100 pump octane. In fact, ethanol is considered an octane enhancer that raises the overall octane of the gasoline/ethanol mix more than you'd get by simple proportions. Now the refiners take advantage of this and may use a lower-octane base gasoline in E10 to achieve their desired octane rating. Regardless, if the pump says 91, then the mix should be 91 or better.

While I certainly agree that ethanol increase the octane rating, it typically reduces the mileage compared to non-ethanol enhanced gasoline.

YMMV

 

[Checkswrecks]

Totally agree about the overly paranoid bit.


As for alcohol, naturally you're right about it being a booster. When writing that it'd affect a person more, I was thinking in terms of mileage and other potential complications that it's brought.

 

[markjenn]

While I certainly agree that ethanol increase the octane rating, it typically reduces the mileage compared to non-ethanol enhanced gasoline.

Most get the theoretically-predicted and test-confirmed 3% drop with E10 (pure ethanol is about 30% less so 10% x 30% = 3%) but some complain bitterly of worse mileage. Of course, mileage is one of those things that is all over the map. YMMV is right.

- Mark

 

[dcstrom]

Still running 91 but plan to test 87 after breakin is complete.

I don't think in most circumstances there will be an issue with 87 - you can bet Nick Sanders didn't run Premium most (or any) of 50000 miles in his Pan Am x3 ride...