My opinion:

It's never a bad idea to run the best fuel you can get. However, your bike's motor was designed to run on 91 octane, due to it's compression, cam profile, and timing/tuning. I have ran Susie on 87, when I am in the middle of nowhere, and she ran great! Nevertheless, I always put 91 in her when it's available. In my Supercharged Mustang, 91 is the minimum I run, becasue detonation under boost destroys pistons.[&:]

Long story short......just run 91 unleaded. Save the money for lunch on the road.

~Joe

 

Yep, regular ol' leaded avgas is plentiful here, although places aren't supposed toput it in anything other than an airplane. I know in the last couple years it had been replaced in Europe with a leadless fuel tho. They are supposed to be replacing 100LL here in the State in the next year or two, but they don't even have a suitable sub yet from what I hear.


Mike

 

Thread drift here: There's no good reason to use 100 octane in our everyday scoots. It may have a use that hasn't been considered.

When I pulled my boat out at the end of the season I took it to the original dealer for "winterizing". The engine is a 70hp Evinrude 4stroke outboard. When I picked up the boat to put in storage everything seemed to be in good order. That evening I was looking at the bill to see what they did. There was this small ($2) charge for "Avgas". I was puzzled as this boat has had the same service done at the same place annually since new in 2000. I went to visit the service writer the next morning about this. The answer I got made sense. The Avgas is used for the engines final run to "rinse away" as much ethanol based fuel as possible. Ethanol may be a better fuel additive(oxygenator) than MBTE but it can trash gaskets and seals if left to sit for an extened period. I was told that Avgas doesn't have any ethanol in it. I'm really curious now, is this fact or fiction?

 

I'm 99.9% sure that is fact. The big thing with Avgas isit's purity. They useTEL (lead) for an octane boost (anti-knock), but mostly it's made up ofhighly refined petroleum products. Aircraft engines in general are WAY behind the engineering curve compared to automotive engines. So, care is taken to ensure a good clean fuel that won't harm the engines. The purity of the fuel is also one reason your engine oil becomes black sooner. It literally washes the carbon deposits off of the cylinder heads and valves in automotive engines.

BTW, I stand corrected. It looks like they are exploring the possibility of using 82UL as a 100LL substitute. Unleaded fuel, without the additives. That I believe is what Europe is already using.



Mike