Octane question

[bwalker]

Similar, yes. Identical... No.

Read my graph. That is a chart of the scientifically measured speeds.
Now a crafty argument would be that iso-octane might very well have a slower flame front, as it is not exactly "higher octane premium gasoline". This would be a valid argument, except that iso-octane is the fuel used as the standard for establishing octane levels.

Given that we can see different chemical fuels burning at different rates, it is somewhat ridiculous to assert that different chemicals will have an identical burn rate. The trick comes in how closely you measure, how exacting your science. Your "expert" was a retired master mechanic, that probably never had any possible way to measure the speed of a flame front. My cited article was from a Master's degree thesis at a university. Science vs anecdotal evidence.

I know which side of that argument you will choose to believe, and I won't hold it against you. But you still need to study up a bit more.

BTW: here is how "Octane" is measured: https://pei.org/wiki_pei/octane-number/
Be careful! You may yet change your mind as to whether higher octanes burn slower than lower octane fuels.

I work in refining, buddy. The components for regular and premium come from the same pool. ISO octane or alkylate is present in both regular and premium gas in varying amounts depending on the day or hour.

Regardless the fastest burning fuels you will find are pro stock drag fuels, which are also very high octane. VP has this info on their website.
I realise what I am saying challenges the orthodoxy of many, but that's only because guys over the years have taken old wives tails as fact and passed this non sense down.

 

[ZeroJunk]

So we've determined you don't know what detonation is...

Babble Babble Babble

 

[Seachaser]

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.

Shelf life is pretty long if the container is filled to the top so not much air can get in. I have used it two plus years old.
I use e free in every engine except vehicles. Diesel in my three tractors. E free in zero turns, boat, chainsaws, weed eaters, blowers, etc.
Normal gas will attract water, the reason I’ve always been told to leave as full as possible.

 

[pdqdl]

The components for regular and premium come from the same pool.

So does the bitumen they put in the asphalt they make roads with. That doesn't mean that it will work well in your gas tank. I'll bet it burns considerably slower, too.

Each chemical has it's own properties, regardless of the pool it comes from. Most alkanes of similar molecular size will have similar properties. If they weren't just a bit different, there wouldn't be all those chemical engineers working at the distilleries, would there?

 

[pdqdl]

That has nothing to do with premium burning faster or slower than regular..

Ok. We have established that you cannot read a graph. I'll not trouble you with any more sciency stuff.

 

[056kid]

Somewhat askew to the topic, but I once tried to run a Stihl 064 as well as a 660 on diesel fuel! They both ran with throttle! However they didn't want to idle.
This was during a period of Stihl coloring their 2 stroke oil red. I grabbed an oil jug full of what I thought was mixed gas due to it's location (in my saw stuff cabinet) & proceeded up to the fall & buck. Filled up with what was actually offroad diesel after burning my 1st tank of the morning. Saw wouldn't run right all of the sudden. Not like water in the gas which happens, but something different. Didn't bother thinking & grabbed a different saw. Cut the tank of fuel poured from the 5 gal jug at the crummy, then refueled with my jug of red gas, and same thing lol. Then like a light switch, it occurred to me. Actually I just sniffed my "saw gas".
As stated, both saws ran with throttle, revved fine and all, they just wouldn't idle. I didn't try to cut anything. Neither saw sustained any damage. Had you asked me to bet on whether or not a chainsaw would burn diesel, I would've lost.

 

[Bill G]

I see the peeing match is still going on.

 

[HarleyT]

I see the peeing match is still going on.

As we get older, our prostates give us trouble,
coupled with the diuretics.

 

[sean donato]

Somewhat askew to the topic, but I once tried to run a Stihl 064 as well as a 660 on diesel fuel! They both ran with throttle! However they didn't want to idle.
This was during a period of Stihl coloring their 2 stroke oil red. I grabbed an oil jug full of what I thought was mixed gas due to it's location (in my saw stuff cabinet) & proceeded up to the fall & buck. Filled up with what was actually offroad diesel after burning my 1st tank of the morning. Saw wouldn't run right all of the sudden. Not like water in the gas which happens, but something different. Didn't bother thinking & grabbed a different saw. Cut the tank of fuel poured from the 5 gal jug at the crummy, then refueled with my jug of red gas, and same thing lol. Then like a light switch, it occurred to me. Actually I just sniffed my "saw gas".
As stated, both saws ran with throttle, revved fine and all, they just wouldn't idle. I didn't try to cut anything. Neither saw sustained any damage. Had you asked me to bet on whether or not a chainsaw would burn diesel, I would've lost.

Depends on how much gas was in the tank yet. Did this same thing to a Cushman in my youth. Had about a 1/4 tank of gas and like an idiot I topped it off with diesel. In my defense we stored all fuel in the same color cans, just had to drip a bit out and look at it. I didn't as I was in a hurry. Got halfway out the field and se started to slow down and smoke pretty good. Kept moving. My pops knew just what I had done. Told me to keep it moving and getback to the shop. So long ad it was flat to tithe floor it ran decent. Wouldn't idle. Oops. We all screw up from time to time.

 

[KASH]

For 49 years my family ran a remote water acsess only fishing resort.It was located about a half a mile from the goverment landing where the guests would park their vehicles.
We had a great group of 8 or 10 guys from Trevour Wis who would come up every year for the Memorial week of fishing they had their own motors Johnson 9.5 hp and would rent boats from us they also had their own mix oil. They would all share the chores ie cooking fish cleaning gas guy etc but this year a new guy was the gas guy.I was away rooming and boarding to attend high school in ThunderBay my younger brother was still at home and was completing grade eight at the one room school grades one threw eight located on the other side of the lake.
We had twelve 45 gallon gas barrels and two fuel oil barrels the gas barrels had a red painted band on the center and the fuel oil a black band.The two fuel oil barrels were newer and less faded .
We would load the empty barrels into a boat and drop them off at the landing and the Texaco bulk dealer located 30 miles east would fill them when he had time.Gasoline and fuel oil are lighter than water so the barrels would float we would tie ropes around the center of the barrels and roll them in the lake six at a time and tow them home three on each side.This was a slow and often difficult task if it was windy.On this day there were 12 gas and two fuel barrels on our beach the two fuel barrels were 10 feet from the gas barrels. This party was great as we gave them a barrel pump and a 45 gallon barrel and they mixed their own gas.The new gas guy asked my brother Eddy which one was their barrel and he pointed and said right over there pick one.Later in the day the new gas guy picked the nicest drum put the pump in and with his special stick which told him how much mix oil was needed in each tank he filled the four boat tanks one tank only needed a small amount.
Later that day the four boats left to go up the lake to fish. Around seven that evening I got home haveing hitch hiked the seventy miles home I was home a short time and Eddy and I were talking and he was telling me that it really bugged him that these guys were calling him ABC I told him dont sweat it its all in fun about five minutes later one boat towing three others pulled in and the outboard on the tow boat is running pretty rough.I checked things out and figure out they filled the tanks with fuel oil then they started to tease the new gas guy and my brother said loud and clear now who is the ABC.They never called him ABC again.
All the motors ran till they tried to idle.
Kash

 

[Bill G]

As we get older, our prostates give us trouble,
coupled with the diuretics.

I am already there. Lots of Tamsulosin (Flo-Max) Now back to the show.

 

[056kid]

Depends on how much gas was in the tank yet. Did this same thing to a Cushman in my youth. Had about a 1/4 tank of gas and like an idiot I topped it off with diesel. In my defense we stored all fuel in the same color cans, just had to drip a bit out and look at it. I didn't as I was in a hurry. Got halfway out the field and se started to slow down and smoke pretty good. Kept moving. My pops knew just what I had done. Told me to keep it moving and getback to the shop. So long ad it was flat to tithe floor it ran decent. Wouldn't idle. Oops. We all screw up from time to time.

Well, given that the saws ceased to run, I'd venture to say that no gas was left. I imagine the engine temp was of some contribution to them actually running.

 

[Husky77]

Boy, this went on a bit
Ignorance is bliss so they say.
Petrol goes in can, add oil and mix. Pour into chainsaw and cut wood........ I could go on but cant waste time today, loads to do.

 

[bwalker]

So does the bitumen they put in the asphalt they make roads with. That doesn't mean that it will work well in your gas tank. I'll bet it burns considerably slower, too.

Each chemical has it's own properties, regardless of the pool it comes from. Most alkanes of similar molecular size will have similar properties. If they weren't just a bit different, there wouldn't be all those chemical engineers working at the distilleries, would there

No, asphalt is not part of the gasoline blending pool...

 

[bwalker]

Ok. We have established that you cannot read a graph. I'll not trouble you with any more sciency stuff.

I'll humor you. What does the graph tell you?

 

[ZeroJunk]

Personally, I think you can get 27 angels on the head of a pin.

 

[ryan1025]

Haven’t read this thread and not looking to go anywhere near the banter above but I saw a YouTube recently that was an ah ha moment. Regarding filling up at a fuel station with ethanol free fuel. If you’ve noticed some stations have a shared hose/nozzle for all fuel ranges, while some have a dedicated hose for ethanol free. If the person before you pumped 87, there’s about a third of a gallon in that hose until your ethanol free comes through. So if you’re only filling 1 gallon…you’re ethanol free fuel is 1/3 leftover from whatever was pumped prior. Makes sense when I thought about it. Probably not an impact to guys buying large volumes but for a homeowner like myself…something to keep in mind. Link below.

 

[Ol' Brian]

Haven’t read this thread and not looking to go anywhere near the banter above but I saw a YouTube recently that was an ah ha moment. Regarding filling up at a fuel station with ethanol free fuel. If you’ve noticed some stations have a shared hose/nozzle for all fuel ranges, while some have a dedicated hose for ethanol free. If the person before you pumped 87, there’s about a third of a gallon in that hose until your ethanol free comes through. So if you’re only filling 1 gallon…you’re ethanol free fuel is 1/3 leftover from whatever was pumped prior. Makes sense when I thought about it. Probably not an impact to guys buying large volumes but for a homeowner like myself…something to keep in mind. Link below.

I'm surprised people are just now figuring this out...

 

[pdqdl]

I'll humor you. What does the graph tell you?

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.

 

[sean donato]

I'm surprised people are just now figuring this out...

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.