gas hi performance or premium?

[thatguy]

So my question is i have a carb sled but does it make a difference if i were to use a 110 octane gas run it straight or mix it with premium or just run straight premium. And whats the disadvantage and advantages of either way

 

[markoo]

If your sled is stock you should run what the manufacturer recommends. any higher will lose power. if you have mods like a higher compression head or some aftermarket pipes you may need more octane. the trick is to run the lowest octane without having detonation. some sleds like the m1000 run on 87 and will run crappy with 91.

 

[Iron Horse Racing]

If your sled is stock you should run what the manufacturer recommends. any higher will lose power. if you have mods like a higher compression head or some aftermarket pipes you may need more octane. the trick is to run the lowest octane without having detonation. some sleds like the m1000 run on 87 and will run crappy with 91.

X2....high octane fuel dose not make power without higher compression, you can buy low octane race fuel that is oxygenated, but I dont believe the small gain is worth the money over pump gas....

 

[barleyfarmer]

When I buy fuel in town I'll go with regular and some good octane boost.Small town with only 3 gas stations that usually only fill their premium tanks in late Jan or early Feb!Hardly anyone uses premium fuel all summer so you have no idea what kind of octane the premium has by fall!Fresh regular is still better than old premium!Just my two cents!

 

[knee deep in it]

X2....high octane fuel dose not make power without higher compression, you can buy low octane race fuel that is oxygenated, but I dont believe the small gain is worth the money over pump gas....

you are correct. This is a common misunderstanding. Octane is a measure of the fuels predictability, not power. Higher octane fuels are more predicatble because the traces of highly explosive components are removed. Because it is more predictable, you can use higher compression heads to make more power.

Running high octane fuel than what is needed actually reduces the hp of the snowmobile.

 

[moyiesledhead]

Not exactly. Octane is a measure of a fuels resistance to detonation. To make fuel resist detonation they actually make it burn slower.

Edit: Actually let me clarify...they make it harder to ignite.

Here's a reasonably simple explanation I found:

"Higher octane ratings correlate to higher : This being the amount of applied energy required to initiate combustion. Since higher octane fuels have higher activation energy requirements, it is less likely that a given compression will cause uncontrolled ignition, otherwise known as autoignition or detonation.
It might seem odd that fuels with higher octane ratings are used in more powerful engines, since such fuels ignite less easily. However, detonation is undesirable in a spark ignition engine, and is signified by audible "pinging" or in more extreme cases "knock"."

Ya, I know...clear as mud! The difference between "detonation" and "preignition" is just as misundertood!