With the bike it gets 91 or higher, but with my car right now it is 92 or higher due to the PCMs advanced timing.  Filling up the car gets a little costly, sometimes I treat it to a little CAM2 high octane but it is not that good for the O2 sensor.  I use a stock R/T PCM when I use the spray but now I have an empty bottle so I put the Mopar PCM back in.  If gas goes up any more the stock one is going back in and I'm going to sell the other one.

i have used the Sunoco 100 in my bike and really have seen no difference.  The car likes it though, but at 3.99 to 4.25 a gallon it don't get it that much.

If you think super is better put it in. What's it cost you? An extra $1 a tank? It certainly won't do any harm.

Quote from: lman123the manual says to use 91 or grater octane.

Look up a few posts... that's not AKI (US octane rating).  GSs take 87 AKI (and if your state offers lower, like Kerry's, it's perfectly happy on 85, too).

Quote from: dannoIf you think super is better put it in. What's it cost you? An extra $1 a tank?

But if you think super is better, you're not basing that on any rational premise - and I can think of better places to spend that $1.  Over a summer of riding, that adds up to a nice bit of gear (gloves, helmet, anyone?).  

I run premium, because it's not exactly going to break the bank.  2 gallons in?  A whopping quarter?  Not exactly a silk scarf.

True about the higher octane making no difference on the GS's engine.  But FWIW, I found this to be interesting- "Paduan" over at Beginnerbikers.org, worked for a refinery and this was his take on premium versus regular:

http://www.beginnerbikers.org/showthread.php?t=2862&page=2

Now, why the premium should have less water in it is beyond me, since it is used less on average (I know this from working as a gas attendant, dropping the sticks into the tanks every night to measure use).  But the poster is someone whose advice I regard highly.

Like I said, FWIW.

If he's right, and that regular is the dregs of the refinery, then the next step up might be an idea, at least for winter storage (along with a dose of STA-BIL) just be be carburetor safe.  An interesting thought.

But for normal riding, the handbook says Regular and I haven't noticed any problem with the bike, or any of my other motors for that matter.  As

Roadstergal says, a penney saved is a step closer to buying something else for me or my bike.  

who uses premium?

rich people with money to blow.

here's my non scientific point of view. normally i use premium. i've only used regular once n that was when i ran out of gas in the stix and had to ask for some off of a stranger. it did seem to have an affect on performance but then again the gs is not a performance bike. so using regular shouldn't hurt (my oldsmobile's used regular since '87 n still runs well), but why not spend an extra 50 cents on premium per fillup.

here's some facts on different fuel ratings:
http://www.epinions.com/content_2346164356

I ran out of gas once and a friend, who owns a plane, only had avgas (127 octane).  I can't say I noticed any differance at all.  Not even in the low end.

Quote from: Remy_Marathe"Paduan" over at Beginnerbikers.org, worked for a refinery and this was his take on premium versus regular:

Quote"Regular" gas is often reformed or cracked, which means that the molecules have been modified forcibly. This grade is often unstable, and causes the fuel system problems people incur with "stale" gas.

I have a chemistry minor, and as that statement stands, it's .

Quote from: mjmcondorbut why not spend an extra 50 cents on premium per fillup.

You can spend an extra buck per fillup putting a couple of drops of Chanel #5 in the tank, too.  And it will have the same effect on performance.

I wanted to make my first post important, but for some reason i'm moved to respond to this old thread to hopefully help clarify a few things.
 In a perfect world, the OCTANE rating of fuel is the percentage of that fuel that is made up of the specific hydrocarbon 'octane' (H18 C8). Pure octane would be a stable, smoothe burning, pressure resistant gasoline when in actuality standard gas is made up of hydrocarbons ranging from something like 4-10 carbons instead of the ideal 8. In terms of engine performance, the octane rating doesn't matter unless you are dealing with a high compression/performance type engine that could possibly prematurely ignite the fuel/air mixture of a lower rated fuel.
   When refinement of oil was in its infancy, the octane rating of fuels (by modern standards) was well below 50 which made for lots of knocking, lots of backfires and all the other symptoms we think of old rickety autos. With the volatile fuels made up of all the less stable hydrocarbons, engines would fire less often from a spark than from the pressure simply combusting the mixture in the cylinder before full compression (this is the knock).
  For the purposes of this thread, a lot of the argument back and forth about propaganda of the oil companies and better "get up and go" from better fuel isn't a product of the octane/premium rating. A few people have mentioned that the additives, detergents etc make up a large divergence from one brand to the next and this is where a lot of the performance or lack there of will be felt. Also age/moisture level of the fuel will play a roll so if you have a crappy tank it could be "wet" from improper storage, transport or any other number of factors. I would say that the GS doesn't need high performance fuel simply because it doesn't compress enough or run hot enough for it to make a difference so that extra 20-30 cents a gallon can be saved for other excesses...like performance motorcycle oil  :mrgreen:

Welcome!

Good info.

Hmmm.  Although your explanation of octane rating is correct, I disagree with your conclusion.    Let me start off by saying that the difference between 87 octane and 93 octane (which is what my choices are here in GA) are neglible...

...but as to which one would be better...   you said yourself that the octane rating measures how close the fuel is to the combustibility of octane (meaning that  87 is more prone to combusting at a diff temperature & pressure than pure octane..which is what these engines are designed for).   Now... as a two cylinder 500cc engine, you of course realize that the bore size on a GS is larger than that of your run-of-the-mill four cylinder bike.   The larger volume makes for a larger probability of premature (or late) ignition of the fuel mix in the chamber.  

Even though we are really splitting hairs here...  it should be clear that ceteris parabis, higher octane fuel will run more smoothly in a properly tuned engine.    I submit (without any concrete evidence to back up my claim) that those of you who say they notice that their engines run worse with higher octane fuel probably have valves that are off spec.

I shall patiently wait for someone who knows engines to disagree with me .

Quote from: EMTkidI wanted to make my first post important, but for some reason i'm moved to respond to this old thread to hopefully help clarify a few things.
 In a perfect world, the OCTANE rating of fuel is the percentage of that fuel that is made up of the specific hydrocarbon 'octane' (H18 C8). Pure octane would be a stable, smoothe burning, pressure resistant gasoline when in actuality standard gas is made up of hydrocarbons ranging from something like 4-10 carbons instead of the ideal 8. In terms of engine performance, the octane rating doesn't matter unless you are dealing with a high compression/performance type engine that could possibly prematurely ignite the fuel/air mixture of a lower rated fuel.
   When refinement of oil was in its infancy, the octane rating of fuels (by modern standards) was well below 50 which made for lots of knocking, lots of backfires and all the other symptoms we think of old rickety autos. With the volatile fuels made up of all the less stable hydrocarbons, engines would fire less often from a spark than from the pressure simply combusting the mixture in the cylinder before full compression (this is the knock).
  For the purposes of this thread, a lot of the argument back and forth about propaganda of the oil companies and better "get up and go" from better fuel isn't a product of the octane/premium rating. A few people have mentioned that the additives, detergents etc make up a large divergence from one brand to the next and this is where a lot of the performance or lack there of will be felt. Also age/moisture level of the fuel will play a roll so if you have a crappy tank it could be "wet" from improper storage, transport or any other number of factors. I would say that the GS doesn't need high performance fuel simply because it doesn't compress enough or run hot enough for it to make a difference so that extra 20-30 cents a gallon can be saved for other excesses...like performance motorcycle oil  :mrgreen:

Quote from: Chris_BIm just curious, after reading though the "Whats Your Gas Price" thread, it seems alot of people (or at least more than I thought) are running premium in their bikes. It was my understanding that you should run the lowest octane fuel you can without pinging. Its not like the GS is a super high compression race engine that requires premium just to run properly. It runs just as well on regular, right? Why the premium?

Premium and "regular" are the same gas. Neither is refined more than the other. Premium is just harder to combust which is great for high compression engines but for the GS, ~87 octane is what should be ran since it's only 9.0:1 compression which is low on a "high performance" scale.

Quote from: subc...
premium here.
new bike and i don't want to mess it up.

You do know that "premium" fuel isn't refined more than "regular", right? It isn't a cleaner fuel, it's all about combustion and the compression of your engine.

Quote from: phirePremium is just harder to combust

It is harder to detonate via compression.  It will ignite just as well as regular when sparked.

Quote from: nightshade000'Premium' is a horrible word for this because it leads the average consumer to think it is always going to be better, when in reallity, the word 'premium' should be placed on the refinery making the gas and addatives.

+1 !

I buy the cheapest 87 in town.  I also use the cheapest 10W40 Wal Mart brand oil.  (Can't beat $0.88 a quart)

Speaking of cheap oil... Has anyone ever actually used that Lucas Oil Stabilizer stuff? I'm always playing with the little wheel when I go to the parts store and am waiting to be checked out.

Quote from: phireSpeaking of cheap oil... Has anyone ever actually used that Lucas Oil Stabilizer stuff? I'm always playing with the little wheel when I go to the parts store and am waiting to be checked out.

Naw, it's too expensive.   :mrgreen: