What octane is best, and why

[davidwyby]

You shouldn't notice anything for dozens of tanks, later on down the road the exhaust port "not" carboned up or the plug "not" being black with particulates and fouled. The canned gas should be categorized as what it doesn't have in it.
I don't use canned gas unless I find it on sale .

I was curious as to starting, throttle response, and power since my can of pump gas has evaporated a lot.

 

[huskihl]

I was curious as to starting, throttle response, and power since my can of pump gas has evaporated a lot.

If it’s got ethanol in it, I’d dump it into something else after a month

 

[pbillyi69]

$5 and $5.50 per gallon!!!!! Seriously??? That is nuts imo.

yep its super stupid its cheaper to make ethanol free gas and its better gas but all of the corn farmers have really good lobbyists and have made it into the oil business. which has other negative consiquences in the form of not enough feed corn for the cattle growers so it has driven the price of corn way up. they are pretty smart for them but for the rest of the world we just get the shaft again

 

[davidwyby]

If it’s got ethanol in it, I’d dump it into something else after a month

Yeah. Up there I think the issue you guys have is that the ethanol absorbs moisture from the air. Down here we don’t really have that so it’s more the good stuff evaporating. Maybe less of an issue. I have taken apart old saws from San diego where they do have moisture and found the white crusties in them. I’m down to the last bit of these two gallons and then I’ll probably go 1 gallon at a time fresh unless I’m doing a lot of firewood or milling. And of course anything that is going to sit like my 49sp (had it a couple few years now) or stock 3120 will get canned fuel and started occasionally.

 

[LoneOak]

yep its super stupid its cheaper to make ethanol free gas and its better gas but all of the corn farmers have really good lobbyists and have made it into the oil business. which has other negative consiquences in the form of not enough feed corn for the cattle growers so it has driven the price of corn way up. they are pretty smart for them but for the rest of the world we just get the shaft again

You have been lied too, have you ever heard of "Distillers Grains"? Please spend a few moments and read through these two Websites to better understand the lies you have been told.
https://www.iowacorn.org/corn-uses/livestock/distillers-grains
https://distillersgrains.org

 

[Wolverine]

I enjoy these types of thread because I take a lot from them.

@Bull Mountains We have a large distribution place near my work. I see trucks of all local gas stations filling up there. Are each adding their own special blend of detergents etc? I know multiple people that justify spending more on the premium on the fact that they believe it's keeping their engine cleaner because there is “more” in the premium.

 

[Kiwioilboiler]

I enjoy these types of thread because I take a lot from them.

@Bull Mountains We have a large distribution place near my work. I see trucks of all local gas stations filling up there. Are each adding their own special blend of detergents etc? I know multiple people that justify spending more on the premium on the fact that they believe it's keeping their engine cleaner because of this.

View attachment 310143

NZ has only one refinery mate, and I work there. The Truck Loading Facility is just outside the work fence. All the brand's collect diesel and mogas (gas or petrol) there. Same base product. Two octanes of mogas, just one diesel. The truck driver pipes his load in, adds the brand additive and off they go.
Premium refers to an octane rating here, 95 RON, so I can't speak to that sorry. What I can say is the octane can't be changed by an additive at the truck, it's blended that way Inside the Fence.

 

[pbillyi69]

You have been lied too, have you ever heard of "Distillers Grains"? Please spend a few moments and read through these two Websites to better understand the lies you have been told.
https://www.iowacorn.org/corn-uses/livestock/distillers-grains
https://distillersgrains.org

you're right i have been lied too. thank you for correcting my misinformation

 

[Nutball]

A friend gave me a saw that he said wouldn't start, it had been sitting outside all winter. I didn't even try to start it, I just checked the carb: clean. Checked the gas, it didn't look right, so I dumped it, put fresh gas in, and it started. Having not tried starting it on the old gas myself, I don't know if stale gas was the problem, but it seems to have been.

Pretty much D Wayne. We just call them 'the light ends'.
If the container is sealed the expansion of gases should mostly remain in the container.

https://www.garden-kit.co.uk/products/aspen-fuel/why-petrol-goes-stale

I know very little about gas, but I don't like a lot of what I see in that web page. I think too much bias and overselling was involved in writing it.

I completely agree on the "how to recognize stale petrol" part. That's what was in that saw.

so of the choices why or why not the 100ll avgas its the cheapest e/free gas of them all

It contains lead, but that's your choice if you want to breathe the exhaust.

 

[Michpatriot]

As little octane as needed to stave off pre ignition or detonation.. Any more than needed is counterproductive in my experience. But more octane will allow more ignition advance, and lower EGTs sometimes, if you are looking for less popcorn after filing your key on the flywheel ..you can try more octane..and maybe find more grunt. But if you get an engine balanced on the edge using octane as the hedge..you might not like the expensive results from grabbing some mystery fuel from a can on the jobsite. When I was young and into fast two strokes but still very green I had a Yamaha yz80 that ate two Wiseco pistons, about 15min a piece, years later I spoke with a guy who knew the builder of that exact bike..he knew it was bored .050 over and then told me it had a advanced stator or ignition and had been tuned on 110 octane.. 12 yrs old and paper route money bought 87 octane..that one stuck with me. Brian Swinks old bike I was told..Ill say this it went like a scalded dog on 87..they run great on aluminum..right before they blow.

 

[whitesnake]

People hate on 100ll...just curious...I'm pretty sure all gas had lead in it back in the day. Many of those people are still alive and well. Now I'm not promoting lead I understand in general it's dangerous. But is running 100ll in your saw a death sentence?

 

[pbillyi69]

i personally wouldnt be worried about the exhaust from running it. i work at a railroad and am exposed to so much more toxic crap on a daily basis than there would be in the exhaust. not to mention all of the things i have purposly ingested in my younger days

 

[pbillyi69]

with all of the information that has been posted here about running the lowest octain that you can and lots of people swearing by 87 why does all of the recomendations from the saw mfgs say use efree with minium of 89 and the gas that has there stamp of approval is 94? 94 isnt in the pumps here 92 is as high as it goes unless you by racing gas or avgas

 

[pbillyi69]

then there is also stihl motomix at 35 a gallon its 92 octain and trufuel that is 22 a gal

 

[Egg Shooter]

with all of the information that has been posted here about running the lowest octain that you can and lots of people swearing by 87 why does all of the recomendations from the saw mfgs say use efree with minium of 89 and the gas that has there stamp of approval is 94? 94 isnt in the pumps here 92 is as high as it goes unless you by racing gas or avgas

Just guessing here but it might be two reasons mainly I think. One, oil mixed in the gas lowers octane. How much? No idea. The more oil the lower the octane of the mix. The other, often ope sets. A higher starting octane would help still have enough "pop" in the fuel after setting. Just me thinkin on this.

 

[cus_deluxe]

People hate on 100ll...just curious...I'm pretty sure all gas had lead in it back in the day. Many of those people are still alive and well. Now I'm not promoting lead I understand in general it's dangerous. But is running 100ll in your saw a death sentence?

people also used to burn witches "back in the day"...yes gas had tetraethyl lead. turns out its super *f-wording toxic. so now its not in gas anymore.

 

[FergusonTO35]

Could be as simple as the OEM's not trusting that 87 is always up to standard.

 

[huskihl]

Could be as simple as the OEM's not trusting that 87 is always up to standard.

I always looked at it like how good is 87 with ethanol after it sat in a can for a year. If it loses octane overtime, maybe that puts it down around 83 or 84 which will pre-ignite in most saws. But 91 might only drop to 87 in that same amount of time, which is still good enough. I honestly have no idea though, just theorizing

 

[5155]

Yesterday I drained half tank from saw into glass.
Today there is a liquid quarter sized slug in bottom.
Not looking like water. Who knows?

As careful as I am I have no control over what is coming out of that pump nozzle.

I see big franchise station get supplied by small name trucks. Maybe it's "meets or accedes" or, who knows.

 

[Rogee]

What do you put 100 RON in mate?

I generally run my Mazda turbo on it because it seems to like it and just get the same for all my saws woodspltter etc