Octane question

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He posted this as it's own thread, and I explained if the person pumping the fuel is too stupid to dump a few gallons in their truck/car before filling a can up, deserve whatever they get in the can.
Ever since they came up with the "3 grades of fuel, 1 hose" dispensers, I always wondered what I was getting in that first gallon, LOL
 
No, asphalt is not part of the gasoline blending pool...

If you consider that it often comes out of the same oil well it does. Since I'm not remotely connected to the oil refining business, you'll need to explain what you mean by "blending pool".

For the purposes of this conversation, I was using bitumen as an example of a much heavier molecular weight hydrocarbon with which to compare the flame speed with high octane fuel. In general, it is pretty easy to see that the smaller the molecule the faster it burns. Similarly, we can also see that the heavier the molecule, the more energy it releases when burned completely.
 
@bwalker

I was unaware that you work in the oil refining industry. I know very little about it all, but find everything quite fascinating. I don't typically expose myself to cancer causing substances. Although sometimes there is no way around it when the task at hand is in need of completion. I have a friend who owns/operates a hand full of leases in the Bend Arch Forth Worth basin who I've learned a lot from. How far from 87 octane gasoline are the intermediate to higher molecular density gasses that come out of a well bore, or annulus? Naphtha, hexane, pentane heptane, butane, propane, octane, to name the only ones I can think of... I know, I need to read, but so far it's reading something about what I just read to understand what I'm reading. My pal tells me that the high API crude he pumps is quite refined straight out of the ground. It's all very interesting(& confusing).
 
It shows the velocity of the combustion of various fuels across a range of air mixtures. The maximum speed of each fuel's combustion occurs at different air mixtures, and it also shows which is fastest according to the maximum velocity reached.



Notice that iso-octane is the lowest curve, exceeded only a small distance by "gasoline". So we know that the emperical standard for a grade 100 octane burns a bit slower than gasoline.



I

would have liked to have seen the chart plotted against the flame velocity under variable pressures. I suspect, however, that might be a really hard thing to measure, as each fuel will produce different volumes of combustion gases.
Iso octane is a high quality stream that is blended into finished product in small amounts. Depending on the refinery maybe not at all.
Extrapolating that premium burns slower slower than " regular gasoline" based on what iso octanes flame speed doesn't tell you much at all.
Also consider the air fuel ratios commonly user in a motor are outside the range for your chart.
Also realise that the fastest burning fuels, IE pro stock drag fuels also have very high octane numbers.
Octane is a measure of a fuels stability under pressure and heat and really doesn't have much to do with flame speed. However a faster burning fuel will tend to have a higher octane number. If you truly understand what detonation is this last point makes complete sense.
 
@bwalker

I was unaware that you work in the oil refining industry. I know very little about it all, but find everything quite fascinating. I don't typically expose myself to cancer causing substances. Although sometimes there is no way around it when the task at hand is in need of completion. I have a friend who owns/operates a hand full of leases in the Bend Arch Forth Worth basin who I've learned a lot from. How far from 87 octane gasoline are the intermediate to higher molecular density gasses that come out of a well bore, or annulus? Naphtha, hexane, pentane heptane, butane, propane, octane, to name the only ones I can think of... I know, I need to read, but so far it's reading something about what I just read to understand what I'm reading. My pal tells me that the high API crude he pumps is quite refined straight out of the ground. It's all very interesting(& confusing).
It's an interesting and challenging industry to work in. Never a dull moment and the pay can't be beat.
The down side is your exposed to all kinds of toxic crap. Which is why in my free time I try not to stack more toxic stuff on top of it.
Bakken crude from North Dakota is very light. It would no doubt run in a older diesel engine right out of the ground.
The stuff we refine is Canadian heavybtar sands oil, which is full of nasty stuff like H2S etc.
 
@bwalker
Very cool!!
Your adamancy on the topic of tiny oil balls now makes slightly more sense. Ironic how I went to oil to compare the severity of these aerosolized used oil globes. Seeing the oil, gasses & aerosolized fluids blowing out of the top of a tank battery & shaking the pipes while Liquid propane & other hydrocarbons begin to boil as they rise! Thus causing more gas to boil! Next thing you know casing pressure is higher than in the well bore and a kick is in full swing as oil rushes in through the standing & traveling valves!!! Common in wells that have been down for a couple of months as I understand it.
That seemed like a great "calm down, there're worse situations out there" thing. But you've probably seen all that and much more, many times! Man I don't know why oil is so exciting, but it is!
 
I'm not sure what 2,2,4- trimethylpentane's claim to fame is other than setting the standard knock rating of 100. Had to use something.

Now, babblewalker can babble about that.
It's claim to fame is it allows a refinery to blend it with garbage to hit 87 octane.
Its expensive to make and the unit that makes it is very dangerous due to the use of HF acid.

FOAD BTW.
 
Why are you quoting him, thought he was on your side. Kind of like junior high .
Yeah I don’t think he meant to quote me.

In my experience, I have found Ben to be correct more often than not. Don’t agree with everything he says nor how he says it, but that’s what makes us individuals.

I’m not arguing one way or the other with octane levels burning good or bad or fast or slow since I can’t prove or disprove any of it. Too low octane = bad. Too high doesn’t hurt but doesn’t help
 
He posted this as it's own thread, and I explained if the person pumping the fuel is too stupid to dump a few gallons in their truck/car before filling a can up, deserve whatever they get in the can.
I’ve just been hosing the first half gallon on the ground… Makes way more sense to put it in my rig.
 
I’m not arguing one way or the other with octane levels burning good or bad or fast or slow since I can’t prove or disprove any of it. Too low octane = bad. Too high doesn’t hurt but doesn’t help

That's about all it amounts to. Use high octane non-ethanol if you can get it. Use a name brand oil, preferrably synthetic since they have it now. Run 40 to 1 , sort of splits the argument. If you can't get non-ethanol keep the container sealed and don't keep it over a couple of months. If you are a home owner and aren't going to use that much buy the canned pre mix.
 
That's about all it amounts to. Use high octane non-ethanol if you can get it. Use a name brand oil, preferrably synthetic since they have it now. Run 40 to 1 , sort of splits the argument. If you can't get non-ethanol keep the container sealed and don't keep it over a couple of months. If you are a home owner and aren't going to use that much buy the canned pre mix.
Around here, no one buys the premium fuel. So it just sits in the tank. I’m a firm believer that we should use whatever fuel is fresh, with a slight emphasis on higher octane if possible. And E-free when possible
 
He posted this as it's own thread, and I explained if the person pumping the fuel is too stupid to dump a few gallons in their truck/car before filling a can up, deserve whatever they get in the can.
That is fine unless you drive a diesel All joking aside you can offer to give someone on the other side of the pump a gallon or so but they might look at you funny.. :) I guess you could take a second can and give it to a neighbor who uses it.
 
The Echo manual says to use at least 89 octane gas, with a maximum of 10% ethanol.
I only have 87 octane e-free fuel around here (I'm not going to pay $11.25/gallon for 110 octane e-free fuel thats sold near me).

Should I just use 93 octane @ 10% ethanol and call it a day?
Or will adding something like (Lucas Oil octane booster) to my 87 octane, e-free fuel serve me better?

I already plan on draining the fuel tank and running dry for storing my Echo CS-620p any length greater than 3 days.
I know the optimal solution would be to just use 89+ octane, e-free but I just cant find any within 45 mins+ drive.


Thanks for your time fellas!

I used to use 89 octane ethanol in my my old Echo 450P chainsaw, trimmer, and hand-held blower until the local Echo dealer (same one I purchased from) said that my using the ethanol fuel is what ruined the carburetor in the hand-held blower and not covered under warranty. I was frustrated because the manuals said 89 octane and no more than 10% ethanol were fine.

Now I spend the money on 94 octane ethanol-free fuel. I go for a year at a time sometimes to go through 5 gallons. When I was helping friends clear their property of trees, I went through 5 5-gallon cans in a year. I get the VP 5-gallon cans from NAPA and/or the local Stihl dealer. NAPA sells them for cheaper.




That's what I use.
 
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