Gas Octane?

The little sticker on the right hand side of the frame tells ya 87, but I use 93 cause I'm weird :nod:

 

If you want best performance, run the 93. Generally speaking, the ECU will adjust timing and fuel to adapt to less than ideal fuel and temps. I am not sure whether sportbikes have knock sensors but if so, they will retard timing when detonation is detected. Retarding the timing reduces power. Fuel with higher than needed octane rating doesnt give as much power so you want to run the lowest octane you can without the timing being retarded from the optimum setting.

Matt

 

3 out of 4 of my bikes call for 93. Not sure on my 600. If the label on the bike specifies 87 then run it. Nothing to be gained running 93. My previous post assumed all bikes spec'd 93 as that is all I have seen in recent years.

Matt

 

Run either what the manu. recommends or whatever is available that doesn't cause knocking. I'm lazy and since my GSXR takes premium all my toys use premium (don't have to fill up twice or have separate containers for 2 bikes).

 

MR-12 race gas is 87 octane, the lower the octane the more power. Higher octane gas is for high compression engines. Oxygen is the key to HP in gas. Example U4.4 isn't a high octane but is mixed with oxygen. Cheapest 7 HP you can buy

 

MR12 is 87 octane
U4.4 is 103 octane

Both are oxygenated, use U4.4 in high compression motors that require high octane fuel, use MR12 in motors that can tollerate lower octane. MR12 makes more power, but can cause issues if you're running super high compression.

 

Thank you Jeremy I knew it was something like that lol

Is there any easy way to measure compression? I have no clue if my engine is built or not. It is fast though

 

You can use a compression tester. I tested my track bike when I bought it used to make sure all the cylinders were working fine. The compression was a little higher than spec if I remember correctly, but they were all about the same. I've heard those aren't always very accurate, though. The engine was re-built, but I'm not sure about the details. The previous owner said he had it tuned for 87 octane and used 87 octane since it was bought new.

high compression + 87 octane = bad?

 

Correct. If it calls for 87 run 87 otherwise you are throwing money away. Run 93 if you have aftermarket electronics that have a custom ignition map for it.

 

I don't think the compression test gives you the compression ratio. I don't think the comp test tells you anything other than a poor seal.

 

bikes like 91+, now if you have 90 octane available get it, the least amount of octane to prevent the detonation will yield you the best burn, the higher the octane the higher the flash point, hence 87 burns faster than a 93, but that also gives you better fuel economy (not that, that really matters for what we do) i know guys that get their bikes tuned for 87 & run mr-12 when they want race fuel, similar to what jeremy explained

 

I agree with those above on the least octane you need to prevent detonation. That said I run 90 octane in mine since a local distributor sells the "recreational" fuel, otherwise known as E0 (none of that ethanol stuff to mess up things).

 

Running 93 when the bike calls for 87 will just rob you of power, LOL@ people that run 93 for no reason, I run both in my k8 GSXR since I got the ECU reflashed to have a map for both using the stock mode switch feature.

 

jealous :cry:

 

Not all things are as they seem.

If you bike calls for 87+, run 87.
If it calls for 91+ run that.

MR12 is 87 MON rating, not the typical R+M/2 rating you find on pump gas.

More octane will not produce more power, unless you tune the bike for that octane (e.g. ignition mapping).

-X

 

op:

 

What oil should I run?

 

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