I have always ran premium in my XRS but i have some buddies and family that say have alway ran regular and say that premium is a waste of money...they say you get better performance outta regular???? sounds nutty to me?
Sled Gas Question???
- Thread starter SHEFFY40
- Start date
nutty indeed, it actually makes no sense. the higher the octane the better it burns and runs, like all other machines on earth...
T
Turbo Monster
Member
I know my 03 800 ho had to run premium only.I would not run regular unless you want to be build it
normally, you can get away with lower octane unless otherwise specified. my yam says premium fuel only, min octane 91. i personally run 92 in all but the race sled. 5-8 gal on the avg @ .10 per gal is cheap insurance verses poor quality low octane. couple extra bucks at the pump verses cost of a rebuild is a no brainer in my opinion. safety first. just my .02 worth.
I have always put 91 in my sleds, which they call for. I cannot justify being on the cheap end to save a couple dimes every time I fill up, which might possibly require me to rebuild an engine later on. Unlike cars, sleds have a more difficult time (if impossible) adjusting to poor/cheap/lower octane gas and do cars. Cars can adjust to these differences (probably not years worth), but with the simpler engine of a 2 stroke it is best to run what the manufacture recommends, in my opinion.
I will always run premium (91) in my sleds. Like stated b4, they are much smaller engines and are much less tolerant to the crappy gas we are sold these days. Don't get me wrong, I always run regular in my truck, and the owners manual says it is ok to use in the sled, but I figure for a couple dollars extra, it is better performance to give the extra few pennies
I only run regular if I can't get premium, and I run the key in the regular setting too. I have never been able to tell a difference in power or running on prem vs. regular, but I figure the prem is cheap insurance.
It's true. IF you don't need the octane, performance is better on the lower grades. Don't mistake octane with energy content. However, higher octane lets you do things to your engine that really increase power (higher compression, advanced timing, boost, etc) and gives some peace of mind.
Were talking pump fuels here. Always buy your fuel from a high volume station.
Were talking pump fuels here. Always buy your fuel from a high volume station.
regular
higher octane explodes at a slower rate than lower octane....so it prevents denotation on really high compression engines because high compression creates more heat...there is no advantage to using more octane than required and an engine will run best on the lowest octane that it can properly run on....87 in my M7 just like the guys that built the thing recommend
higher octane explodes at a slower rate than lower octane....so it prevents denotation on really high compression engines because high compression creates more heat...there is no advantage to using more octane than required and an engine will run best on the lowest octane that it can properly run on....87 in my M7 just like the guys that built the thing recommend
S
snoboy
Active member
NOPE
higher octane explodes at a slower rate than lower octane....so it prevents denotation on really high compression engines because high compression creates more heat...there is no advantage to using more octane than required and an engine will run best on the lowest octane that it can properly run on....87 in my M7 just like the guys that built the thing recommend
YEP
Last edited:
I've been trying to read on this some and my take is that detonation is basically when the fuel explodes without using the spark from the spark plug. The compression alone causes it to fire, similar to how a diesel engine works. Problem is if it fires before the spark the timing is off and it pushes the piston before it's ready. Higher octane is less likely to detonate in some engines, thus allowing higher compression. Once you get past the detonation issue, all fuel gives similar power on one given engine. I've heard different stories on whether or not higher octane will actual hurt performance or the engine seals, etc. I don't think there is any real evidence either way.
Todays cars can adjust the timing and retard it if detonation is occuring so there is no gain in using higher octane than the owners manual states. My question is are there any sleds with knock sensors?
My manual states 87 minimum. I usually put in 89 just to be safe if I get a batch of bad gas or if it sits for a while. I'm also confused about how the whole 10% ethanol used around here affects sleds.
Experts please feel free to correct me if any info is wrong.
Todays cars can adjust the timing and retard it if detonation is occuring so there is no gain in using higher octane than the owners manual states. My question is are there any sleds with knock sensors?
My manual states 87 minimum. I usually put in 89 just to be safe if I get a batch of bad gas or if it sits for a while. I'm also confused about how the whole 10% ethanol used around here affects sleds.
Experts please feel free to correct me if any info is wrong.
i learned alot on this post...
S
skidoo_guy
Well-known member
My real question is my summit says use 91 octane, but what I suspect is that they put that on there so you use 91 at sea level but it probably isn't needed at elevation because there the high compression domes become regular compression domes and this would allow me to use regular 87 at elevation. Let me know if this sounds right to everyone. Lots of times prem is about .20 a gallon more at Cooke City, MT.
Do you really want to risk it for $2 a tank? If my manual said 91, I'd put it in and skip the pop and candy everyone picks up from the gas station. It sure beats risking a new engine.
I believe the octane requirement is also relative to altitude. I've noticed many fuel stations in the mtns which sell 85 octane at the pump and at lower altitudes the lowest common fuel is 87. Gotta believe there is a reason for this.
My Doo Summit states 91 octane and includes clutch setting charts beginning at sea level. I've never heard or seen anything in writing that says I would need to run higher than 91 at sea level. Therefore - at 10,000' where the air is much thinner and compression is much less, the octane requirement would be less.
I still run 91 most of the time to be safe, but I have run 87 without problem too. My Cat 900 requires 87 so when at the pump it is more convenient to use one grade in all. I've also put 91 in all too at times.
Jim
My Doo Summit states 91 octane and includes clutch setting charts beginning at sea level. I've never heard or seen anything in writing that says I would need to run higher than 91 at sea level. Therefore - at 10,000' where the air is much thinner and compression is much less, the octane requirement would be less.
I still run 91 most of the time to be safe, but I have run 87 without problem too. My Cat 900 requires 87 so when at the pump it is more convenient to use one grade in all. I've also put 91 in all too at times.
Jim
