When I bought my GS500 the mechanic told me to put premium in it (93 Octane). I've filled up my bike about 4 times with it now but I've been reading online that my bike is supposed to take regular unleaded.

What should I be putting in?

If i switch to unleaded can I just start filling it with that or do i have to drain everything before I switch?

Thanks.

Nope.  Dump the cheap stuff in and go ride.

There's no reason to be running 93 in a GS, unless it's 95F+ outside.  Then, it does cut down on pinging a little.

No, don't dump the premium, just throw regular in from now on.  That wasn't the mechanic.  That was the floor sweeper!    Putting premium in a bike with 9 to 1 compression, you're just wasting money and increasing emissions.  Like Geep said, you don't need premium in this bike.  Its fuel requirement is 87 octane. (regular)  Just like the manual sez! 

Quote from: Faint on March 01, 2009, 10:23:57 AM
When I bought my GS500 the mechanic told me to put premium in it (93 Octane). I've filled up my bike about 4 times with it now but I've been reading online that my bike is supposed to take regular unleaded.

What should I be putting in?

If i switch to unleaded can I just start filling it with that or do i have to drain everything before I switch?

Thanks.

Aww, are you trying to start a fight? It seems like every time someone asks this question people are very much for one side or the other... I'm all for cheap gas though. The engine is low compression and designed to run on low octane gas, why spend more on something it doesn't need?

Bump for the owners manual comment.  on pagw 2-2 of my 2005 Gs500F manual it says 87 octane

I do tend to notice a slight bit more stumble when the engine is really cold with premium, but other than that there's no difference in performance. So no reason to run premium and more reason to run regular.

Either.

K, switching to regular.

Thanks!

Quote from: bill14224 on March 01, 2009, 12:10:54 PM
you're just wasting money and increasing emissions. 

Where's yhour proof for a statement like that?

most premium fules actually advetrise the fact their fuels will make less emissions.

Quote from: galahs on March 01, 2009, 11:30:25 PM

Quote from: bill14224 on March 01, 2009, 12:10:54 PM
you're just wasting money and increasing emissions. 

Where's yhour proof for a statement like that?

most premium fules actually advetrise the fact their fuels will make less emissions.

Not around here... I doubt that burning premium gas creates more emissions, but I would bet that making it does. It is a more refined gasoline, so it probably takes a bit more energy to make, which is probably why it costs more.

In Australia (probably other countries too but I don't know for sure) premium is more than just a higher octane fuel compared to standard. They also contain additives which are supposed to help clean your engine. A cleaner engine means a more efficient engine and better burning of the fuel, this is what leads to the claims for them being better for the environment. The other difference is the reason I don't use it in my GS. Most premium fuels are higher density which should mean you need less fuel for the same power if your engine is using it correctly. However small carburettor engines (small by car standards, 1300cc formula ford race engines fit into this category for example) are unable to properly atomise the fuel which actually results in a loss of power and economy and a rougher running engine. While I have never confirmed this in the GS I did confirm it in my ZZR250. It ran notably smoother and produced better economy on standard as compared to premium. So since I've had the GS it has only had standard.

i vote for closing and locking ALL fuel or oil threads after the first coherent reply.

yes, "I lost my keys so gas doesn't matter !" counts.

Higher octane fuels are harder to ignite, hence the ping reduction. They require more compression (more heat) and a good, hot spark. So, if you have a low compression engine, yes, the burn is less efficient and leads to carbon deposits on valves and pistons.

Quote from: galahs on March 01, 2009, 11:30:25 PM

Quote from: bill14224 on March 01, 2009, 12:10:54 PM
you're just wasting money and increasing emissions. 

Where's yhour proof for a statement like that?

most premium fules actually advetrise the fact their fuels will make less emissions.

Want proof?  Here you go:

http://neons.org/neontsb/TSB/14/140897.htm

http://blogs.consumerreports.org/cars/2008/02/premium-gas.html

http://www.slate.com/id/2182076/

http://www.edmunds.com/advice/fueleconomy/articles/106293/article.html

I'm not familiar with Australian fuel standards but I do know that octane ratings worldwide vary from U.S. standards, so 87 or 91 octane here may not be 87 or 91 octane overseas.  The right idea here is to use the lowest octane fuel you can without the engine knocking.