2011 RS 91 octane?

[capt.jim]

I was looking at a 2011 RSS at the dealers and noticed they now recommend 91 octane on the sticker next to the gas filler, instead of 87 octane, like my 08 requires. Still 10.8 compression, i don't know anything else that has changed that would require 91. I looked at BRP's website specifications between the RS and RS-S and the RS shows 2.24" 57MM throttle bodies and the RS-S shows 2" 51MM throttle bodies, a typo?

 

[IWN2RYD]

I was looking at a 2011 RSS at the dealers and noticed they now recommend 91 octane on the sticker next to the gas filler, instead of 87 octane, like my 08 requires. Still 10.8 compression, i don't know anything else that has changed that would require 91. I looked at BRP's website specifications between the RS and RS-S and the RS shows 2.24" 57MM throttle bodies and the RS-S shows 2" 51MM throttle bodies, a typo?

I asked this as well... Was told no typo by the dealer... I am running 89 with the TB Pro JB.

 

[Raptor]

I am currently running some experiments using 89 octane mid-grade fuel instead of 91 octane "premium." So far after 3 tanks of the 89 octane fuel I see no drop-off in performance or mileage at all. I'm starting to think this so-called "premium" gas isn't so premium after all except for price...

 

[ARtraveler]

Based on what I am reading, I am going to try lower octane for both my Spyder and my Subaru Tribeca SUV. The way gas prices are--$.20 per gallon savings can add up. I went from 90 octane down to 89 octane for the last two tanks on the Subaru--I have not noticed any performance difference. I did put a fresh tank of 90 octane in the RTS to clean it out after the long winter sleep--next tank, I am going to try the 89 octane for a couple tanks--and then the game plan is to go to 87 octane. I will let you know what happens with my experiment. If this does not sound like a good idea--let me know.

 

[musicarcade]

I've been running 89 in my 2003 Subaru WRX Sportwagon w/ no probs. I occasionally put a half tank of premium after 2 fillups of 89.

my 2008 SE5 has been running great on reg. so I see no sense (cents?) in changing that.

 

[sandrunr1]

The lower the octane the hotter the burn. If it doesn't ping, it is OK. 87 usually is alright. But if pinging occurs, up it to the next level.

 

[capt.jim]

I asked this as well... Was told no typo by the dealer... I am running 89 with the TB Pro JB.

Well, i just don't understand this, the RS and RS-S are the same motor, 10.8 compression, 106 HP, yet the RS has 57 MM throttle bodies and the RS-S has 51MM throttle bodies like the 100 HP RT? Makes no sense to me.

 

[NancysToy]

Well, i just don't understand this, the RS and RS-S are the same motor, 10.8 compression, 106 HP, yet the RS has 57 MM throttle bodies and the RS-S has 51MM throttle bodies like the 100 HP RT? Makes no sense to me.

They could have made unknown changes in the ECM to give it more zip. Changes in spark or cam timing can effect the octane needs. Smaller throttle bodies make little sense, unless the originals were so big they made the intake air "lazy". I wouldn't buy the numbers unless I saw the two side-by-side or was able to measure, myself. BRP has made errors in their specs before.

 

[capt.jim]

They could have made unknown changes in the ECM to give it more zip. Changes in spark or cam timing can effect the octane needs. Smaller throttle bodies make little sense, unless the originals were so big they made the intake air "lazy". I wouldn't buy the numbers unless I saw the two side-by-side or was able to measure, myself. BRP has made errors in their specs before.

Yes, they have, I think bumping up the timing enough to require 91 would show a slight increase in torque or HP, I don't think anything has changed. I just happened to notice the throttle body discrepancy while i was looking to see if anything had changed compression wise for the new RS's to use 91 instead of 87 octane like my 08. Being that this is my first street bike I'm not sure how noticable pinging would be to me with the tupperware, exhaust and wind noise, maybe the BRP tech's noticed some evidence of detonation in some teardowns or something, just looking for a reason. The salesman said they all use 91 now, popped the seat and there it was, 91. If i have to run 91 octane i want the 12.2 pistons and one of ken's camkits sounds good to me.

 

[KipDM]

i believe the throttle body size difference is a typo.

also, i bought a 2011 Spyder RS-S :spyder2: and was given an RS book, is there actually a different owner's manual for the RS-S?
because in the RS manual it says to use 87 octane.
always use the recommended octane because going higher octane can cause knocking, while going lower octane can cause pinging (at least in cars, not sure about cycles).

 

[bone crusher]

Ut oh...do I have to dig up all those articles about the octane not really making a difference?

The higher octane won't make a big enough difference to justify its price.

 

[Bob Denman]

This might not be about parts... Could it be about fuel quality?

 

[M2Wild]

The lower the octane the hotter the burn. If it doesn't ping, it is OK. 87 usually is alright. But if pinging occurs, up it to the next level.

:agree:

Octane is about burn rate and detonation, not price. Performance degradation comes from the ping detector telling the ECM to advance the timing thus not being as efficent resulting in some power loss. Air / Fuel mix determine how rich it runs. Lean mix burns hotter. My Miata SC is built to run on 91+, anything lower than that I will be risking blowing it up (well .... killing the compression). Atleast this is how I understand it.

 

[boborgera]

Ut oh...do I have to dig up all those articles about the octane not really making a difference?

The higher octane won't make a big enough difference to justify its price.

I know this is not Apple's to Apples, On my Hemi truck the book recommends 87' But if you dig deeper into the book it also says if you use 89' you'll get more performance and better MPG's.
I find when i use 89' in my hemi it gets at least 2/3 more miles per gal. And i can feel the performance gain.

 

[Bootie]

I know this is not Apple's to Apples, On my Hemi truck the book recommends 87' But if you dig deeper into the book it also says if you use 89' you'll get more performance and better MPG's.
I find when i use 89' in my hemi it gets at least 2/3 more miles per gal. And i can feel the performance gain.

Let's do the math:lecturef_smilie:If you get 30 mpg with 87 Octane then 2/3 more would be 30mpg + 20mpg(2/3 of 30) or 50 mpg total:dontknow: I'm afraid I don't quite believe it.:dontknow:

 

[Bob Denman]

Maybe he meant 2/3 of a mpg increase... :dontknow:

 

[fastfraser]

I know this is not Apple's to Apples, On my Hemi truck the book recommends 87' But if you dig deeper into the book it also says if you use 89' you'll get more performance and better MPGs.
I find when i use 89' in my hemi it gets at least 2/3 more miles per gal. And i can feel the performance gain.

Is that wright ? Would I get 20 more MPG ?

 

[KipDM]

Let's do the math:lecturef_smilie:If you get 30 mpg with 87 Octane then 2/3 more would be 30mpg + 20mpg(2/3 of 30) or 50 mpg total:dontknow: I'm afraid I don't quite believe it.:dontknow:

i am positive he meant 2-3 mpg increase ('cause if you got actual 2/3 EVERYONE would buy the highest octane!). LOL. people on the web expect accurate math term usage? LOL.:spyder:

 

[boborgera]

i am positive he meant 2-3 mpg increase ('cause if you got actual 2/3 EVERYONE would buy the highest octane!). LOL. people on the web expect accurate math term usage? LOL.:spyder:

Correct,; 2 to 3 MPG more, Not two thirds.hyea:
You can only get Two Thirds if you use the water tablets that's sold on E- bay

 

[Eraser]

Correct,; 2 to 3 MPG more, Not two thirds.hyea:
You can only get Two Thirds if you use the water tablets that's sold on E- bay

:agree: uh...:roflblack::roflblack::roflblack: