Are you really buying 93Octane?

[CROSSBOLT]

Way to go, Tromper! Great info!

Karl

[ole two wheels]

I know we're not talking cars here, b u t, The modern high performance auto engines, especially the 4 valves per and double overhead cams all have VVT now that is computer controlled. That's why they all have , "premium fuels only" or, "for optimal performance use premium fuels" in their owners manuals. Lower octane gasoline cannot handle the variances in the valve timing that these engines produce. As far as I can tell, my DT300 is just as happy with regular or Premium gas. If I'm going on a longer, high speed jaunt, such as express way travel, I give her a shot of the high stuff. My 1100 Honda Shadow has after burn in the exhaust if I use premium. Even though it sounds cool, the pipes have turned a pretty blue and gold and the section that's right under my right thigh required two heat shields. One regular gas it is much more user friendly. None of this probably has very little to do with this thread, but I just felt like writing. My main concern with U.S. gas is not so much the octane, but the fact that they are no longer required to post the percentage of ethanol you are getting.

[Tromper]

Not sure if the premium really will help anymore on long runs for a liquid cooled vehicle, where I had issues was with air cooled on long WOT jaunts, both my old bug & bus and my air-cooled scooters.

Far as discoloration on stainless pipes, I think that's more the heat than anything else.  Modern exhausts tend to run hotter than former days by intent since the O2 sensor need to be extremely hot to work correctly.  If ya like it cool, if not any good metal polish will take off the discoloration for a while.  Did that on my lamented lost NT.  Thought it looked spiffy, but am glad O bought a couple drill attachments to do it...hand rubbing it was taking a long time.

[Forbes1964]

I can’t see why we complicate matters. This question is relevant ONLY for vehicles who’s MANUFACTURERS recommend or require high octane fuels. A company is NOT interested in having their product self destruct with the resulting increased warranty claims. Therefore, we can trust their fuel recommendations. If they say 87 octane (check their method of measurement) then 87 should be fine if it’s running right. If the compression is 11 :1 , and they recommend regular, they have determined that REGULAR is sufficient.  Advanced designs with better air fuel mixtures, improved combustion chamber design, and precise computer controls have made it possible to run significantly higher compression ratios on regular fuels. The same is true for cars too.

Now if your Scooter sits long enough for the fuel to degrade, then higher octane may be beneficial simply because the DEGRADED fuel loses octane. But if you ride regularly, just use a quality fuel from a station that sells a lot of fuel. Anything else just makes YOU feel better.

If the Scooter won’t run right on the recommend fuel, something is wrong with it. And the higher octane fuel is simply masking a problem. It’s true for cars, true for scooters.


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[Tromper]

Fair point.
Most folks are mystified by the whole octane thing, & really many don't even know the relationship to tuning, so just assume the "good stuff" is better to the point where the myth perpetuates itself.
That sort of thing is a lot of what creates this sort of thread.  The modern injection system and several other factors surrounding modern computers controls do add some interesting questions in that regard; however I will note that I rarely get any bump from using high octane in my fully computer controlled Burgman 650.   Usually only when the winter blend is particularly bad for a week or so.

[Stig / Major Tom]

Always gave my kids skim milk.
My mother in law said they'd have been smarter on whole milk.
Too late now.
Dang....
Shoulda used the hightest.
(Mr. Forbes makes good sense. As usual.)
Stig

[CROSSBOLT]

Ah, yes! There are at least three souls who get this octane thing. I would like to say that my job, therefore, is finished, you have done well but that would be presumtuous beyond fantasy! It is so satisfying to see that most of this bunch are not swayed by the urban assumptions!

Karl

[Mr. Paul]

Ah, yes! There are at least three souls who get this octane thing. I would like to say that my job, therefore, is finished, you have done well but that would be presumptuous beyond fantasy! It is so satisfying to see that most of this bunch are not swayed by the urban assumptions!

Karl

Make that four Karl! The most expensive, newest, or most popular is not always the best.

[CROSSBOLT]

Yes, indeed, Mr. Paul! Make it four! If Zombie, Vivo and Bettin' and Losing were here would make....ah....SEVEN! At least!

Karl

[Forbes1964]

Always gave my kids skim milk.
My mother in law said they'd have been smarter on whole milk.
Too late now.
Dang....
Shoulda used the hightest.
(Mr. Forbes makes good sense. As usual.)
Stig

Thanks Stig. But You just don’t know me. If you did, instead of saying “as usual “ , you’d be saying “for a change” . [emoji23]


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