Non ethanol fuel question

[Gebo]

Just make sure you are getting your non-ethanol gas from a dedicated non-ethanol pump. Otherwise, you will getting some ethanol in your gas. Assuming the last
person that pumped got ethanol gas.

 

[GrumpyCat]

Just buy E10 from a high volume gas station. Only buy a month or two’s supply at a time. Don't store the can on cold concrete because cold fuel with warm moist air condenses moisture from the air no matter ethanol or not.

90 octane (sic) won’t hurt anything, won’t help. When engine is designed for 87 AKI then 87 is optimal. combustion pressures, flame rate, etc.

 

[TonyPrin]

Looks like consensus is that 90 (or may be higher) octane gas doesn't harm small engines despite my posts to the contrary. And that's OK. Several noted that the impact of 90 octane gas versus 87 octane is negligible at most so the benefit isn't worth the incremental cost. Beyond that, ethanol free fuel is less harmful to small engines than E10, but any potential harm can be mitigated by limiting storage to less than 2 months.

 

[GrumpyCat]

The only harm ”from” ethanol is that it carries water in solution, then carries that water into the carburetor. If allowed to sit it will do nasty things. No additive or treatment does any good.

Small engines have ventilated gas tanks, open to the atmosphere, open to collecting moisture. Automobiles have sealed gas tanks with very little outside air axchange.

 

[SamB]

I’m smarter than you. My theory’s are facts, your theory’s are just what you want to believe. Remember, everything you read on the World Wide Web is the absolute truth and based on time honored facts, so what ever you say won’t change my mind.

Seen on the internet...."He's a French Model"

 

[TonyPrin]

The only harm ”from” ethanol is that it carries water in solution, then carries that water into the carburetor. If allowed to sit it will do nasty things. No additive or treatment does any good.

Small engines have ventilated gas tanks, open to the atmosphere, open to collecting moisture. Automobiles have sealed gas tanks with very little outside air axchange.

My understanding is slightly different. Ethanol doesn't create water; it must enter the gas tank at time of purchase or through vents. Ethanol attracts water in the tank which readily attaches to the ethanol. Water in ethanol does inconsequential harm to the engine, no more than water in pure gasoline.

However, ethanol can only absorb a finite amount of water at any given temperature before it becomes oversaturated, causing phase separation. When phase separation occurs, the water separates from the ethanol. At 60F, ethanol can absorb .5% water or approx. 1 1/4 tablespoons of water per gallon prior to phase separation. It is this unattached water that causes damage.

 

[7394]

I test my 100% gas from my same gas station once once or twice a year. Just for my peace of mind.. It's extremely simple to test it.

 

[Skippydiesel]

Just buy E10 from a high volume gas station. Only buy a month or two’s supply at a time. Don't store the can on cold concrete because cold fuel with warm moist air condenses moisture from the air no matter ethanol or not.

90 octane (sic) won’t hurt anything, won’t help. When engine is designed for 87 AKI then 87 is optimal. combustion pressures, flame rate, etc.

I have never used ethanol blended fuel, so some of my commentary is speculative.

• Agree with purchasing any fuel from a high volume/turn over supplier.
• Also only purchasing sufficient fuel for your relativly short term needs (whatever they may be)

Storage of petrol:

Most, if not all, petrol will store for at least 6 months plus, with negligible deterioration. To achieve this, the container must be gas/air tight and filled to 75% capacity or more. If these two factors are met, then the storage temperature has little bearing on its keeping quality.

As has been pointed out by others - Most fuel tanks are open to atmosphere:

• This means that air can enter/exit. Air contains moisture (% will vary according to prevailing condition). Warm air contains more moisture than cold. When warm moist air enters the tank, the moisture will condense, on cold inner walls of the tank, forming free water (droplets), . These droplets will fall to & collect at the bottom of the tank. Petrol with ethanol may absorb some of this water - this is okay as it will have little effect on the combustion process. However the free water at the bottom of the tank may may # rust the tank bottom or # enter the fuel delivery/metering system and cause engine running issues. The solution is to regularly drain the tank sump (if fitted) any water traps and the carburettor float bowl thus removing free water.
• Also means any tendency of the fuel (petrol) to loose volatile components, causing a reduction in fuel quality. Filling the tank (minimising air space) will slow the process, as will mixing in fuel "inhibitors" however for long term storage it may be best to empty the whole fuel system. NOTE: In most short term storage situations, adding fresh fuel to old, will restore most of the fuels performance.

 

[TobyU]

The reason for my question was because when reading up on using a higher octane in small engines, one article said it can cause small engines to run hotter and possibly cause damage to the valves.

They are wrong.
I would venture to say that even an extreme cases they are still wrong!
There's a lot of crap on the internet and a lot of people that think things are true and then they say it and other people believe them.
I'm not going to claim this next statement is absolute fact but I think you take some 108 to 110 octane racing fuel and put it in your lawn mower and it wouldn't get your egts or valves a bit hotter to worry about.
Do you need this much in a lawn mower with approximately 7 to 1 compression ratio?
You certainly do not.
These things are "Low performance little turds". #tm.
That's my little trademark seal because I'm claiming that expression has my own but you're free to use it just know that I invented it.

I tell at least three or four customers weekly that these lawn mower engines are low performance little turds.
They are still far better than anything battery powered though!!

Low performance makes them more forgiving and if they were high performance finally tuned machines squeezing out every last drop of power per cubic inch or do I have to say CC now?

Back to octane, putting 87 versus 91 or 93 in an engine will make no difference and will in no way harm a small lawn mower engine.
Personally, I'm not a fan paying 50 or 60 cents more or sometimes almost a dollar for ethanol free fuel or higher octane.
We've already established you don't need the higher octane and all fuel will still mess up if it sits long enough and I have had things sit over 3 years with simply 1 oz of sta-bil in each gallon of fuel and start right up in about three pulls.
This makes it pointless and a waste of money to buy ethanol free fuel.

Just make sure you never buy their 88 stuff because that has at least 15% ethanol and even the gas cap on the newer mowers tells you never to use that.

 

[TobyU]

All of the premium small 2 stroke manufacturers, aka Stihl Husqvarna, Makita/Dolmar require a minimum of 90+ in their products to prevent pre-ignition which will cause engine damage. But premium fuel doesn't burn any hotter than non-premium fuel because it has the same btu rating. The only disadvantage is the higher cost to operate because in most cases will not change your fuel usage.

And my personal opinion is premium stores better, but that may just be my opinion and could be incorrect.

I haven't found any of the premium fuels to store any better than the standard 87.
I think most feelings that it is is just confirmational bias or some type of bias or wishful thinking.
While some of those fuels, especially shell v power are probably excellent at keeping things clean when they're actually running and preventing detonation and a few other things, none of these companies are refining gas to sit for six or eight months and not congeal or to leave fewer deposits and crud once they do evaporate.