What octane gas do you use?

[Inked Monkey]

Just wondering what octane gas everyone recommends. I always had to use premium in my Ducati and my buddies all run it in their harleys. I've just been putting 87 in my xs650, but should I use higher? It runs badass as is.

 

[kmb81xs650sh]

Just wondering what octane gas everyone recommends. I always had to use premium in my Ducati and my buddies all run it in their harleys. I've just been putting 87 in my xs650, but should I use higher? It runs badass as is.

I was always told by Yamaha mechanics to run the highest octane I could. If I run anything below 89 octanes it pings like crazy. So I try to run 93.

 

[inxs]

- here we get 91, 95, 98, 100 RON...i use 95 in all my bikes

 

[CDNTX650]

shell v-power. no ethanol. high octane.

 

[inxs]

- dont know about nth am but here shell v-power and aral-bp ultimate are 100 ron

 

[bloodthirstysystem]

i think in the manual it says the engine was designed for 95. but it's been a while since i've been in there....

 

[Lunatic]

Note that the way octane is rated in gasoline is different now than when the manuals for these bike were printed. Run premium.

 

[Inked Monkey]

Wow, thanks for the replies. She'll probably run even better with high octance

 

[Tomterrific]

Your bike will probably run the same with premium. What it won't do is blow a hole through the top of the piston when you ride down the highway.

Tom Graham

 

[Inked Monkey]

That would suck! Should I just run the rest of the 87 out and switch or go mix some 91 in with it?

 

[Travis]

I'd probably mix some 91 in with it and be easy on it for that tank.

 

[cooltouch]

I run 93 in all my bikes. And my cars. I'd rather be on the safe side.

 

[skyhawk04kilo]

I run 93 in all my bikes. And my cars. I'd rather be on the safe side.

Higher octane fuels take longer to burn. That means that in an engine not designed to run on premium, some of the fuel won't burn before the exhaust valve opens and you'll be dumping fuel into the exhaust. This results in lower power for the same amount of fuel consumed. This means lower fuel mileage (double-whammy considering 93 costs more). It also means increased emissions. I was always told to always run 93 in every motorcycle, but that's a load of BS. Just use the fuel recommended in your owner's manual for newer bikes and cars.

Think about it. Gas companies would love to do away with 87 and have everyone run 93, because it costs more and they would make more money that way. There is a reason they keep 87 around. Yes, it's cheaper and people would have a fit if they had to buy 93, but that's not the whole story. Low-compression engines actually run better on 87 than 93. Just something to think about...

Having said that, I do agree that it's difficult with an XS since fuels have changed so much since the bikes were produced. Anything in the owner's manual should be taken with a grain of salt. Probably safest to run 93 in a bike designed to run on leaded fuel.

 

[650sf]

My bike gets premium wherever.

 

[cooltouch]

I understand all that. I've tried lower octane fuels in my bikes, and either they'd become hard to start or I'd hear pinging, so I didn't do it anymore. As for my cars, one's turbocharged and requires premium, and the other requires minumum 91 octane. No such thing as 91 where I live.

 

[XSLeo]

If you remember back in the 70's regular gas was 94 octane, hightest was 104. The 650manuals say to use regular gas. Regular when the bikes were built or regular now. The books were written then, so you should use what was regular then. 93 is what most places sell today. Run the 93.

 

[dpawl31]

From what I remember, higher octane is not any more 'potent' than low octane. The octane level merely is a resistance level to detonation.

Meaning if the motor is designed for it, it will run better with the proper gas. If you have an older car and start to get detonation as the miles go up, using premium gets the pinging to go away (detonation). Detonation can happen from hot spots in the motor from deposits staying hot and such.

Our bikes are made for premium, so using less than that can cause detonation because the fuel burns too easily.

Don't quote me on all that, but in the past 2 years that's what I have gained about it.
I use regular in my car, once I hit 100k I will probably go to midgrade. (unless I boost it, in which case the motor will be torn down anyway...) then I will go to premium with a tune!

Bike, atv, boat, all get premium.
I don't trust octane boost that much, but I'll use it if I forget or can't get premium.

 

[Inked Monkey]

Everybody has me scared now, I'm gonna stop by the gas station on the way home and top it off with premium.

 

[dpawl31]

It'll take a damn long time to do serious damage. Don't get too shaken up.

Plus octane ratings are different in different countries. Someone told me once that 87 in the states is like premium overseas. Not sure how much truth there is to that? Something to do with RMS vs something else, lol not sure.

 

[xjwmx]

I think I remember an 87 ever since there were self-serve pumps, which goes back to the 80s at least.

Which octane you need is mostly a function of compression and ignition timing. With these bikes, due to lower than original compression due to wear (potentially) or higher compression due to carbon build up (potentially) who knows what to use? Well, you can use the lowest that doesn't allow pinging.

I used to get pinging even with 93 sometimes - so don't think 93 automatically solves the problem. Listen for pinging under load and look for dark specks on your plug insulators.

Right now I've retarded my timing to the max and use 87 with no pinging, so I'm safe with 87.