A really really really simple question.

[Scorpio X]

Since it's a so basic thing, I can't find the answer anywhere.
Wich type of fuel does the GS 500 run on? I guess it's 95, not 98. I've bougt an -93 and the manual was lost.

[JamesG]

Doesn't matter.  A GS will happily run on the cheap stuff as well as high octane fuels.  I don't recall that the users manual even specifies a recommended fuel type.

Remember the octane rating isn't a mesure of "quality" or "power" its (simply) how much compression it can tolerate before spontaniously igniting (desieling). That is why high compression engines require high octane fuels. But with the GS's mellow 9:1 ratio its not an issue.

[JamesG]

We need a delete function.

[JamesG]

for when we get ham fisted and impatient with the submit button.

[JBix]

The bike takes your average unleaded gasoline.  I put in High octane(91), but medium(89) should work if you are cheap(haha).

[john]

we need a delete function.

Why don't you just edit your previous post :dunno:  Thats what I do wnen I screw up.

As far as fuel goes the decal under the seat saying 91 octane  is 91 by a different method and in actuality 87 octane will work just fine.  As a personal preference I always use super unleaded but it is unnecessary.  I just like knowing there are more detergents in super.

[JamesG]

I did edit them. But there is no "delete this message" button...

[john]

I did edit them. But there is no "delete this message" button...

I think there is a clickable button under the type in your message box (when you are editing your message) that says "delete this post"

[vtlion]

my '97 manual states 87 octane.

the compression is pretty low on the GS.  The bike won't benefit from higher octane fuel, although you can use it if you are so inclined..... any experts out there with a different opinion on this one?...

I've run mine on a tank of 93 once as a 'test' for what I thought might premature detonation.  Other than that I've gone with 87 all the way.

[JamesG]

I think there is a clickable button under the type in your message box (when you are editing your message) that says "delete this post"

Not for us lowly peon users...

[john]

Not for us lowly peon users...

...and a custom title is born...

[JamesG]

gee...  I feel so... specal.

[dmp221]

[quote="john As a personal preference I always use super unleaded but it is unnecessary.  I just like knowing there are more detergents in super.[/quote]

I may be mistaken, but I thought I was told that the additive packages in most major company fuels are identical across octane lines.  I'll ask the local Mobil guy later today.

[alerbaugh]

I've heard that the higher the octane, the cooler the engine runs.  My dad works in the oil/gas industry and says that the BP/amoco premium has the best combustion for premium fuels.  With how cheap it is to fill up a GS tank, there's about a 50-70 cent difference so there's really no biggy.

[Pam G]

I think a higher octane fuel makes it run leaner also.  Probably not a good thing in the long run.  I put 87 in my GS since it hasn't been rejetted I believe.

[vtlion]

the higher octane fuel will burn slower and so detonate at higher compression.  Its used in engines with a higher compression ratio to prevent premature detonation... so the extra cash for 93 isn't worth it unless you have a vehicle that has the proper compression ratio.  It gets rid of knocking in a cylinder that is detonating prematurely because it burns slower, essentially, its a bandaid.. it doesn't 'fix' the problem of carbon deposits or something else causing premature detonation.  So if you run 93 in a working engine tuned for 87, if anything you will get LATE detonation... also not cool because you can actually lose power.

in fact, I've read stories about vehicles that have had problems becuase 93 was used in them... not sure I buy that, but it certainly will not help you.

basically, the octane number is just a mathematically calculated ratio of 'octane' to 'isopentane' and other isomers of octane... each burns just as clean as the other and with just as much energy.  93 does not burn 'hotter' or with more power than 87. Only the rate of the burn is different.  The difference in cost is because of the cracking and refinement process involved in making each type of fuel from crude oil.  Everyone assumes that because 93 is more expensive that it must be cleaner, more powerful, or in some other way universally better.  Naturally, the oil companies aren't in any hurry to bust that myth, since it makes them more $$$.

[yamahonkawazuki]

i believe the "delete this post" icon is at the bottom of the screen when editing a post? :dunno:

[JamesG]

I think you guys are messing with me...

[glenn9171]

In the GS, higher grade than "regular unleaded" is only required if the compression has been increased and/or the timing has been advanced.

There are several ways of measuring octane levels in gasoline.  The numbers in the manual are using a different equation than the numbers on the gas pumps in the US.

***And yes, there is an option to "Delete this post" while editing.  Check the last of the 4 boxes between the text box and the "preview & submit" buttons.

[JamesG]

I only have:

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