Octane question

[sean donato]

What about PRI-G? I've heard a lot of good things about it, enough to where I am using it to stabilize 165 gallons of E-free gas for long term storage. I've even heard people have used it to freshen many-years-old gas to get it usable again.

Edit to add: I will say: I'm storing it in steel 55 gallon drums in a dark, cool-ish area, so that probably will be the main reason it stays fresh.

Few months ago I grabbed a bottle of pri-d and pri-g. Some time this spring I'll pop open the can I treated with the pir-g and see how it does. Only reason I switched from stabil is a friend recommended it, and it's price per ounce treated is about 1/3 of stabil cost.

 

[scut207]

I've never heard of it.
Nothing and I mean nothing will make stale gas fresh. Once the light ends boil off and the rest oxidizes you can't make it better.
Fuel stored in well sealed steel containers does last longer. Any particular reason for having that much gas on hand

So I live in WNY which has all 4 seasons, each sometimes multiple times per year (if you lived here you would get it).

I have some ?s:

1. in a perfect world (continuous temp, relatively low humidity) what is the shelf life of e-free gas stored in a perfect container?
2. approximatly, What is the shelf life in a normal container say during the summer vs winter?
3. is one freeze-frost cycle enough to doom e-free gas in a normal container without stabil?
4. is a normal container of e-free gas with stabil usable if stored from fall to spring?
5. my Gas station has e-free (lucky me) gas but its higher octane (I think 92 or 94) I dont think that negatively affects anything, but do fuel additives increase or decrease shelf life?
6. I'm still somewhat ignorant about the effect of ethanol in gas, other than it destroys rubber components and it seems to attract water, doesn't normal gas also attract water?
7. Should I use e-free gas in my 4-stroke 17hp Kawasaki ride on John Deere lawnmower?

Thanks ahead.

 

[Ted Jenkins]

So I live in WNY which has all 4 seasons, each sometimes multiple times per year (if you lived here you would get it).

I have some ?s:

1. in a perfect world (continuous temp, relatively low humidity) what is the shelf life of e-free gas stored in a perfect container?
2. approximatly, What is the shelf life in a normal container say during the summer vs winter?
3. is one freeze-frost cycle enough to doom e-free gas in a normal container without stabil?
4. is a normal container of e-free gas with stabil usable if stored from fall to spring?
5. my Gas station has e-free (lucky me) gas but its higher octane (I think 92 or 94) I dont think that negatively affects anything, but do fuel additives increase or decrease shelf life?
6. I'm still somewhat ignorant about the effect of ethanol in gas, other than it destroys rubber components and it seems to attract water, doesn't normal gas also attract water?
7. Should I use e-free gas in my 4-stroke 17hp Kawasaki ride on John Deere lawnmower?

Thanks ahead.

As I said earlier there is plenty of misinformation going on here. E free gas has its problems also which can leave a varnish that can cause so much damage. In a perfect world do not store any type of fuel and you will have no problems. Run your chains saws dry then put some stabilizer in them and no more problems. I use half gallon juice bottles which has pretty thick plastic. Even though I go through several gallons a day some times. I can clearly see that the premix is mixed and use all the fuel then grab another. I run all my saws with E gasoline with out any problems going back from when E was introduced. Nobody will have problems from E in their gasoline unless maybe fuel lines start cracking which is an easy fix. Thanks

 

[ZeroJunk]

My neighbor has 50 gallons of gasoline with maybe 15% diesel mixed. Don't ask me how.
We are putting it in our old carburetor pickup trucks maybe 5 gallons to a tank full.
Waste not want not.

 

[bwalker]

What about PRI-G? I've heard a lot of good things about it, enough to where I am using it to stabilize 165 gallons of E-free gas for long term storage. I've even heard people have used it to freshen many-years-old gas to get it usable again.







Edit to add: I will say: I'm storing it in steel 55 gallon drums in a dark, cool-ish area, so that probably will be the main reason it stays fresh.

So I live in WNY which has all 4 seasons, each sometimes multiple times per year (if you lived here you would get it).

I have some ?s:

1. in a perfect world (continuous temp, relatively low humidity) what is the shelf life of e-free gas stored in a perfect container?
2. approximatly, What is the shelf life in a normal container say during the summer vs winter?
3. is one freeze-frost cycle enough to doom e-free gas in a normal container without stabil?
4. is a normal container of e-free gas with stabil usable if stored from fall to spring?
5. my Gas station has e-free (lucky me) gas but its higher octane (I think 92 or 94) I dont think that negatively affects anything, but do fuel additives increase or decrease shelf life?
6. I'm still somewhat ignorant about the effect of ethanol in gas, other than it destroys rubber components and it seems to attract water, doesn't normal gas also attract water?
7. Should I use e-free gas in my 4-stroke 17hp Kawasaki ride on John Deere lawnmower?

Thanks ahead.

In regards to #1 and #2 the answer is it depends. Gasoline is a chemical soup whose makeup changes by the hour. As such its not possible to say.
In regards to #3 freezing doesn't effect gasoline.
In regards to #4 it should and it's been my expiereance that it does, although I wouldn't use it in a two cycle after sitting that long.
In regards to #5 additives have nonmetallic effect on shelf life.
In regards to #6 normal gas does not attract water like ethanol, although it often contains some water from the refining process.
In regards to #7 I use Efree in everything with a carb or anything that isn't used daily.

 

[pistolpeta]

I dont know what you guys are talking bout', Im still using up some Trump era 82 octane I had in a plastic gas can in my little
V-twin motorcycle without a hiccup.
I know its a whole different animal than a small two stroke but made me giggle when It started up with no problem and ran fine (if not a little more throttle response, but that may had just be weather related).

 

[bwalker]

I dont know what you guys are talking bout', Im still using up some Trump era 82 octane I had in a plastic gas can in my little
V-twin motorcycle without a hiccup.
I know its a whole different animal than a small two stroke but made me giggle when It started up with no problem and ran fine (if not a little more throttle response, but that may had just be weather related).

I dispose of all my old premix and skanky gas in the tank of my Tacoma. Doesn't bother it at all.

 

[bwalker]

As I said earlier there is plenty of misinformation going on here. E free gas has its problems also which can leave a varnish that can cause so much damage. In a perfect world do not store any type of fuel and you will have no problems. Run your chains saws dry then put some stabilizer in them and no more problems. I use half gallon juice bottles which has pretty thick plastic. Even though I go through several gallons a day some times. I can clearly see that the premix is mixed and use all the fuel then grab another. I run all my saws with E gasoline with out any problems going back from when E was introduced. Nobody will have problems from E in their gasoline unless maybe fuel lines start cracking which is an easy fix. Thanks

I don't think anyone suggests that storing non ethanol fuel is without problem. It's just less so than ethanol fuel.
Pump gas just doesn't store well these days and hasn't for decades. Ethanol makes it worse because it allows for even poorer quality streams to be blended into the gasoline pool and because ethanol itself attracts water, is hard on rubber and plastics and it grows bugs.

 

[bwalker]

My neighbor has 50 gallons of gasoline with maybe 15% diesel mixed. Don't ask me how.
We are putting it in our old carburetor pickup trucks maybe 5 gallons to a tank full.
Waste not want not.

Diesel fuel and gasoline are pumped through the same pipelines.
When we startup a unit there will often be diesel range components carried over into the gasoline stream. It all gets blended..

 

[ZeroJunk]

Diesel fuel and gasoline are pumped through the same pipelines.
When we startup a unit there will often be diesel range components carried over into the gasoline stream. It all gets blended..

Plantation , or at least before they changed the name for political correctness, runs through my property a couple of thousand feet. Any tips on how to steal some of it ?

 

[Mad Professor]

100LL avgas is rated any the lean/rich scale that's aviation specific although it roughly corresponds with 100 octane R+M/2 that's used to rate pump fuel. One problem with blending premium with race gas or av gas is its not a mathematical scale that determines your end octane rating. In most cases this doesn't matter, but in some applications it does. If your motor requires it run straight race gas. It's a fools errand to guess with an expensive race motor.
Octane boosters like Klotz raise your octane less then 1 number. Unless the treat rates get ridiculous, which introduces all sorts of problems. Most boosters use aromatics like toluene and some use MMT. MMT has a ceiling where by its ineffective and it produces lots of rusty color deposits which can cause pre ignition. The aromatic based boosters cause throttle response issues and are very hard on rubber and plastic, plus they are nasty to inhale, which is why they were phased out from use in pump gas.

I've used xylenes as an octane booster, works good.

 

[thompsoncustom]

well it looks like this has been talked about before on here and some of the pro builders shared there experience.

https://www.arboristsite.com/threads/what-fuel-for-compression.213479/
looks like there's no need for me to do any testing as it's already been done and no stock saw ever requires anything higher than 87.

start to get above 200psi than it's time to think about 89

 

[sean donato]

well it looks like this has been talked about before on here and some of the pro builders shared there experience.

https://www.arboristsite.com/threads/what-fuel-for-compression.213479/
looks like there's no need for me to do any testing as it's already been done and no stock saw ever requires anything higher than 87.

start to get above 200psi than it's time to think about 89

There's no magical compression number thay requires higher octane, especially a static number. Too many other variables in the engine. Just suffice it to say 90% of saws or o. P. E. Don't need any mire then regular pump gas.

 

[ZeroJunk]

There's no magical compression number thay requires higher octane, especially a static number. Too many other variables in the engine. Just suffice it to say 90% of saws or o. P. E. Don't need any mire then regular pump gas.

The only thing I have noticed is on my 27 HP Kohler. It runs fine. No noticeable difference in power. You just have to wait a few minutes to shut it down using 87 or it diesels. With 93 you can turn it right off .
It does not have a fuel shut off solenoid in the carb like a lot of these engines

 

[bwalker]

.

I've used xylenes as an octane booster, works good.

Using aromatics does boost octane, but they are not without any downsides. Fornatarters there not good to breath at all, which is why the EPA severly limits them in the gas pool. They also are very hard on rubber and plastic parts, like crank seals, etc.

 

[bwalker]

The only thing I have noticed is on my 27 HP Kohler. It runs fine. No noticeable difference in power. You just have to wait a few minutes to shut it down using 87 or it diesels. With 93 you can turn it right off .
It does not have a fuel shut off solenoid in the carb like a lot of these engines

Octane is the ability of fuel to resist detonation. What you are seeing is pre ignition. The two phenomenon are totaly different. Higher octane in and of itself won't stop pre ignition.

 

[bwalker]

There's no magical compression number thay requires higher octane, especially a static number. Too many other variables in the engine. Just suffice it to say 90% of saws or o. P. E. Don't need any mire then regular pump gas.

Lots of factors at play. Bore size, rpm, head design,BMEP exhaust design, etc all are factors in a motors octane requirement.
And you are absolutely correct. Most saws have very low compression ratios, small bore sizes, low BMEP and the don't use tuned pipes, which causes them not to need higher octane fuel.

 

[ZeroJunk]

Octane is the ability of fuel to resist detonation. What you are seeing is pre ignition. The two phenomenon are totaly different. Higher octane in and of itself won't stop pre ignition.

Except, it does. As well as 104 octane booster. They both stop the dieseling phenomenon.
Over , and over, and over ....

 

[bwalker]

well it looks like this has been talked about before on here and some of the pro builders shared there experience.

https://www.arboristsite.com/threads/what-fuel-for-compression.213479/
looks like there's no need for me to do any testing as it's already been done and no stock saw ever requires anything higher than 87.

start to get above 200psi than it's time to think about 89

That thread is about worthless..lots of bad information.
For starters static compression isn't what matters. You need to know your compression ratio. Even at 200psi static a saw has a low compression ratio.

 

[bwalker]

Except, it does. As well as 104 octane booster. They both stop the dieseling phenomenon.
Over , and over, and over ....

They may be true in your case, but its not related to the octane.
It sounds to me like you have a carb tuning issue. I would also verify ignition timing.