What type of fuel to use

[bogeyman1]

Hey guys, Iv'e been out of snowmobiling for 20 years and just bought a 2002 polaris indy 500. Everyone I talk to has a different opinion on what type of gas to use.- 87 octane/ 89 octane/ 92 premium octane/ nonoxygenated/ etc. any opinions would be appreciated.

[MuleShack]

I put non oxygenated in mine. Use amsoil 2 stroke oil and put some fuel protector in the tank and it starts right up in the fall with no tune up or anything. (I dont even drain the carb).

[troutkingmaster]

I try to use Non-oxy whenever possible as well. Has nothing to do with the higher octane, just the lack of ethanol to dry out fuel lines, carb boots, etc.

[BoxMN]

Boogeyman, I also have a 2002 xc500. Works great fun sled. I also try to use non-oxy since it is so available up north. I also add a bit of seafoam to each tank. Haven't had them long, but three sleds for three years and no fuel issues. I even started them up a week or so ago just to hear them again

One thing I didn't do correctly with my 500 was to inspect the FULL length of the carbides on the skis. The skis are kinda banana shaped, and right in the middle the wear more than the ends - I just checked the ends, and after putting on new carbides holy cow is this sled even more fun!!! Handles like a dream - but I have not ridden the new ones, so can't compare, haha! It is my dream

[Esox_Magnum]

I run Non oxy Premium (91 down here) thats what mine seems to like.

[311Hemi]

Non-oxy will be the best, but not readily available at all stations. Otherwise, just regular 87. You will not see increased performance from higher octane, so no real reason to use it unless you know for sure it's non-oxy. Not all premium gas is non-oxy.

[pulleye16]

MSRA.com has a list of non-oxy...click on features.

[Esox_Magnum]

Non-oxy will be the best, but not readily available at all stations. Otherwise, just regular 87. You will not see increased performance from higher octane, so no real reason to use it unless you know for sure it's non-oxy. Not all premium gas is non-oxy.

I notice a difference between 91 and 87 performance and milage wise. Runs better but gets worse milage. Now n my truck I dont notice any different preformance but I get better milage on 91 but not enought to justify buying it.

[FasterThanYou23]

I always run 91 nonoxygenated

[311Hemi]

I notice a difference between 91 and 87 performance and milage wise. Runs better but gets worse milage. Now n my truck I dont notice any different preformance but I get better milage on 91 but not enought to justify buying it.

I would venture to guess it may be more temp related that octane related (or a problem with the engine - dirty)......or maybe just better (fresh) gas. Maybe you were getting some detonation with the lower octane gas because the jets in your carbs are dirty, or maybe it's a high mileage sled with significant carbon deposits in the combustion chamber?

I don't see how octane would give you any added HP on an stock engine unless the engine adjusts the timing on it's own. I know there are some newer DI/EFI sleds out that will adjust timing based using info from knock/02 sensors.

If your modding an engine then octane might be a little more important, especially in colder temp when jetting a sled really lean for a given temp. With a stock engine manufacturers jet them conservatively so running the recommended fuel even at low temps should be relatively safe....assuming were not talking a WOT run across a lake at -30* (might be safer to run a higher octane for that!).

I believe vehicles like cars have more sophisticated computers that can actually advance timing parameters forward based on a number of things that the engine is sensing. They can advance to the point of knock and then back off a bit. I don't know much about cars computers though to know exactly how it works.

I know that the 06' Skidoo Rev 600 SDI I had would start out at a setting for higher octane setting (I think for 89 octane) and if it detected any knock it would retard the timing to that would be good for 87 octane, which was the minimum recommended octane for that sled and all I ran in it.

[hydro]

311,

Nicely put. There is so much superstitious chatter here on the supposed benefits of the "non-oxy premium" topic that at times it seems like the holy grail of fuels. Thanks for the explanation, I hope people read it and increase their understanding of what fuel is correct for the application.

[troutkingmaster]

311 and hydro, I agree 100% that many people have limited understanding of what the octane #s mean. The thought being "the number is higher and it costs more so it must make my sled run better". Unless you bump compression or have a knock issue, there is no reason to use higher octane and you will most likely not see any performance gains if not lose performance if the engine is made to run 87. As I stated above, the only reason I use 91 non-oxy when available is to limit the amount ethanol the fuel system sees. I went to school for Automotive Engineering and it is a proven fact that ethanol dries out rubber at a much higher rate than regular gas. On the new sleds, it is probably not an issue as pretty much all new rubber/plastic is not as affected by it but I am a firm believer in non-oxy for older applications. If you could find non-oxy 87 octane, I would run that all day long.

[Rick Reisewitz]

I started to run 87 three winters ago in my first efi sled and i will not go back to 91 you could tell the differents in performance on 87 to 91 on my cat and on my yamaha it has never seen anything other then 87 since i have owned it.

[Bandit155]

One big reason to use non-oxy is that the ethanol will dry out the rubber parts in the carb and corrode the aluminum. Learned this the $300 hard way when I had to replace a carb on my wheeler that I only ran 87/89oxy in. It corroded the carb after sitting for the winter.

[Bandit155]

I used to live in ND and used 87 non-oxy in all my vehicles. Got better mileage in my truck and never had problems with my toys even if they were stored for the season. I don't know how far you live from ND but if you're close they have it. Maybe SD too. I use some Mercury outboard Quickleener additive (12oz. to 72 gals.) pretty often and it sure keeps things running smooth. The Polaris/Mercury dealer in Fergus Falls sold me on the stuff. Works great.