[Rog02]

How To Test For Alcohol Content In Gasoline

I have read several posts in this forum about alcohol content or lack there of in gasoline around the country. There appears to be quite a few misconceptions about whether fuel does or does not contain alcohol.

First off, it depends on where you live. Alcohol content labeling is regulated by the states not the federal government. I live in Missouri and gasoline can contain up to 10% alcohol (the current Federal mandated limit) without being labeled on the pump as to content. Other state will vary (I know IOWA goes as far as to subsidize "gasahol" and it sells for less than gasoline that contains no alcohol).

Octane rating is no assurance of alcohol content or lack thereof. 89 and 92 octane may contain alcohol as easily as 87 octane fuel as long as it does not exceed the 10% limitation. Most of the suppliers around here do not formulate the higher octanes with alcohol unless the price of fuel goes up to a point where it is financially feasible (again, the states have regs on when alcohol must be blended).

The list goes on and on, with seasonal conditions locality and several other factors playing a role in fuel formulation. It gets rather annoying for those of us that have to make this stuff run when the fuel is a constantly moving target.

OK, having said all that, let me show you how to test for basic alcohol in gasoline. Remember I have been testing for this stuff for 30 years so I have the high dollar stuff, but you can do it with nothing more than an empty 16 oz. pop bottle and some simple measuring devices.

The basic tools for testing specific gravity and alcohol. Since we a basically concerned with alcohol content the thermometer and float will not be used. The 100 ml graduated made be replaced with a graduated pop bottle or any type of clear container that can hold gasoline and is sufficient size to contain 10 equal measures of known quantity. More on that later.

Since we will be testing for alcohol content in percentage the quickest and easiest way is to measure 90 ml of fuel into the column. Sampling into a clean small container and then filling the column will make getting accurate amounts much easier. DAMHIKT

Into the column we add 10 ml of water. The water will go to the bottom of the column latching onto any alcohol it come into contact with, so I use the 10 ml (a cc is equal to a ml in volume). By measuring the water before adding, the error factor of initial alcohol contact is minimized/eliminated in the final results. The addition of 10 ml of water actually measured 11 ml in the column, so there was an immediate net gain of 1% just as the water fell to the bottom.

Once the water is added, the column is agitated ( I just cap the top of the column with my hand and shake it up and down with my left hand) so the water and fuel try to emulsify, then set aside to separate for a few minutes. After 10 minutes of settling, the separation line measured 18 ml. This fuel sample is regular 87 octane so it contained the legal amounts of alcohol as expected.

Now, how does one that does not possess a 100ml graduated column perform this test? Find a bottle or jar with straight sides. Use your wife's teaspoon measure and add 2 tablespoons of water to the jar and mark the level using a permanent marker (Sharpy or equivalent) and repeat this until you have 10 equal graduations. Empty the water and dry the inside of the container. Perform the test as outlined above. You might not get the exact percent readings but it will be close enough to know what you are buying for fuel.

Oh yeah, and for those guys that insist on putting "dry gas" in the tank for winter storage, it is methyl alcohol. Over dosing the fuel with "dry gas" will cause problems as well.

Roger
Old, Tired, and Grumpy

 

[Tencubed]

Interesting stuff Roger. Thanks for posting this. Sounds like having a good sediment bowl in a fuel system and using the alcohol laced fuel would do the job to get rid of water in a fuel system.

Is this the reason the fuel filter sediment bowls that are part of the filters on the gas farm equipment seem to collect a cloudy looking liquid rather than the clear water of years past? I've been wondering about the change and suspected it had something to do with the skunk gas we get now.

Mike

 

[Rog02]

Besides alcohol the current fuel contains many "emission modifiers" which may be a contributing factor to the milky fluid in the sediment bowls.

If you look closely at the 4th. pic you will see the water at the base of the column has a milky appearance as well.

Roger
Old, Tired, and Grumpy

 

[dontworrybehappy]

Whats frustrating is that this thread shows why tanks on cars, lawn equipment, everything, need to have fuel drain pitcocks like planes do, at the lowest point in the tank. You'd then be able to drain all that crap out. But they dont.....and we continue to have issues with water and other contaminants in our tanks.

 

[roughrider]

Whats frustrating is that this thread shows why tanks on cars, lawn equipment, everything, need to have fuel drain pitcocks like planes do, at the lowest point in the tank. You'd then be able to drain all that crap out. But they dont.....and we continue to have issues with water and other contaminants in our tanks.

i have installed petcocks on some of my tanks for this it helps keep water out of the carb ...Havent put one on a carb yet tho

 

[Tencubed]

I've been adding Racor brand fuel filters to our equipment for a number of years. The base gives you a lot of options as to what kind of filter and/or water separator you use. I use the fine micron filter with a sediment bowl and drain on the bottom. There are other brands around that work just as well but we keep things as standard as possible and Racor has given us good results.

Wish they made a small version that would fit little equipment.

Mike

 

[Rog02]

Whats frustrating is that this thread shows why tanks on cars, lawn equipment, everything, need to have fuel drain pitcocks like planes do, at the lowest point in the tank. You'd then be able to drain all that crap out. But they dont.....and we continue to have issues with water and other contaminants in our tanks.

I think you guys are missing the point of this test altogether. I added the water! That fuel sample came from one of my fuel jugs ( I used 5 gallon superjugs just like the ones I carry racecar fuel in). The fuel sample was clean and showed no signs of contamination.

The water is added as a re-agent to drag the alcohol back out of the fuel blend.

If you are having problems with water contamination in your vehicle then you need to source your fuel from a different supplier. This is unlikely in this day and age as ALL fuel retailers are required by federal law to have a monitoring system in place. The Veeder-Root systems monitor tank levels and fuel throughflow which must match. In ground steel tanks are pretty much a thing of the past as they are illegal for new installation and the old ones have pretty much been replaced by fiberglass tank which also require the replacement of the plumbing to the dispenser canisters (pump islands). Any steel tank still in the ground is required to have an even more stringent monitoring system due to the corrosion factor which is the leading cause of ground water infiltration and more likely ground water contamination (fuel from the tank seeping into the soil). Above ground tanks have similar monitoring requirements as well as a containment system to contain any leakage. That is federal law!

I can tell you from first hand experience what a PIA the natural resource people can be when they find fuel contamination in the ground water surrounding an underground storage tank. I operated a small municipal airport for a few years and yes it was 100 octane Low Lead. None of the aircraft owners ever reported any trouble with water in the sumps. I never detected any appreciable amounts of water in the dispenser sumps either but the tanks failed the pressure test and had to be removed and replaced as did several hundred yards of soil that surrounded the tank as it was contaminated from decades of fuel leaking. Fortunately the city had to foot the bill for the tank replacement. Ever wonder why the filling stations in town just seemed to all close about the same time? It was because the tanks had to be replaced by a certain date. Many operators just closed the place down and retired rather than invest in new tanks and retrofit the new monitoring systems and tanks.

The fuel quality today is better than it has ever been as for the debris and water but the addition of alcohol and several of the other emission additives has brought about its own set of headaches. Why these additives are in our fuel is a political discussion and I will not even go into it. The fact is they are there and the engine manufacturers know it and make their fuel recommendations taking these thing into consideration.

BTW, the term is petcock not "pitcock" Look it up in FAR Part 1 "Accepted Nomenclature". Actual to drains used on aircraft are called "sump drains". I prefer the Cessna style drains wherever I can legally install them as they are about flush mounts without the tendency of "butterfly drains" to catch weeds and other debris when taxi-ing through tall grass and weeds.

Roger
Old, Tired and Grumpy
Holder of FAA A&P, IA, and ASE Master Tech auto and truck as well as too many other certifications to list here.

 

[dontworrybehappy]

Well, if you google "pitcock" it does come up with quite a few threads. I can't believe the grammar police are out this early in the morning. :fing20:

That being said, mr know it all, you should know that there is more than one source of water for a fuel tank. I would HIGHLY doubt you would get any water through the pump at your local gas station. However, it is VERY likely for you to get water through condensation. That is how most water ends up in fuel tanks. All tanks are vented to atmosphere and that is the main source of contamination in gas.

I stick by what I said earlier. I know you were testing for ethanol but still, it frustrates me how fuel tanks in cars, etc don't come with a sump drain like a Cessna or piper or any plane has. You cannot stop condensation from accumulating water in a tank, you can slow it by always keeping the tank full, but you will never eliminate it.

I didn't miss the point of the thread, I just made a "side" observation and it's ok.

 

[roughrider]

i didnt miss the point i think its a good test myself

 

[roughrider]

Well, if you google "pitcock" it does come up with quite a few threads. I can't believe the grammar police are out this early in the morning. :fing20:

That being said, mr know it all, you should know that there is more than one source of water for a fuel tank. I would HIGHLY doubt you would get any water through the pump at your local gas station. However, it is VERY likely for you to get water through condensation. That is how most water ends up in fuel tanks. All tanks are vented to atmosphere and that is the main source of contamination in gas.

I stick by what I said earlier. I know you were testing for ethanol but still, it frustrates me how fuel tanks in cars, etc don't come with a sump drain like a Cessna or piper or any plane has. You cannot stop condensation from accumulating water in a tank, you can slow it by always keeping the tank full, but you will never eliminate it.

I didn't miss the point of the thread, I just made a "side" observation and it's ok.

You HIGHLY doubt that you would get water in your gas from a station ..Well i hate to brake it to you it is possible and more likely to happen in the winter months i have seen it many times ...It has even happened to me as stated above alot of the older stations where sold off before the tanks where changed ..I have seen the inside of some of these tanks and you would be shocked at what is at the bottom of them

 

[Ken in NJ]

Roger PM sent to you. Hopefully this thread will NOT get so far off track and closed like the "Which Oil" one just was. :thanku:

 

[Ingersoll444]

You HIGHLY doubt that you would get water in your gas from a station ..Well i hate to brake it to you it is possible and more likely to happen in the winter months i have seen it many times ...It has even happened to me as stated above alot of the older stations where sold off before the tanks where changed ..I have seen the inside of some of these tanks and you would be shocked at what is at the bottom of them

Feel free to start a thread about water in motor fuel. Thats not the topic of this thread.


rog02, Thanks for posting this. I have read this procedure before in the past, but Im sure a lot of us would realy like to know. As anyone that works with highly tuned engines know, it can be a BEAR getting it right when the fuel varys so much!

 

[roughrider]

Feel free to start a thread about water in motor fuel. Thats not the topic of this thread.


rog02, Thanks for posting this. I have read this procedure before in the past, but Im sure a lot of us would realy like to know. As anyone that works with highly tuned engines know, it can be a BEAR getting it right when the fuel varys so much!

i was following the posts that where made ..I understand his test and agree with him ...As i race pro street cars and fuel is very important ..Crap gas car dont work right .I dont agree with the other posters statements .... and was backing up the OPs statements sorry i got off topic with the others

 

[Jim_WV]

Very interesting Rog, thanks for taking the time to post your work here, much appreciated :fing32:.

 

[Brad]

Very good information, with clear instructions.

Here in IL they do label the pumps. Funny, some of the lower priced cut-rate stations sell gas that doesn't have alcohol.

 

[JRC0528]

Rog02

Reading back over your simple instructions for testing for the ethanol content got the wheels spinning in my mind (a dangerous thing at times!). For the test, you add water to blended (with ethanol) fuel to 'capture' the ethanol and settle it out in the bottom of the graduated cylinder.

Many here have reported problems from running blended fuel as many small engines don't seem to care for the stuff.
My thinking is one should be able to REMOVE the ethanol from the fuel fairly easily simply by adding water to the fuel.

I would think the process would work something like this:

1) add a few cups of water to several gallons of fuel (perhaps you could recommend how much water-to-fuel Roger?)

2) agitate well

3) allow to settle out

4) drain off water/ethanol from bottom of container

5) enjoy your ethanol-free fuel!


Let us know if you think this would work. If anyone else wants to test this theory let us all know the results (and take pics of your testing rig!).

 

[monteman_73]

I understand your logic JRC0528, (Not trying to attack you here.) but what will you do with the contaminated water? Here is another way of looking at it. Just to make it simple, let's say gas is $3 a gallon. If it contains 10% ethanol and you are going through the trouble of using water to eliminate the ethanol, now you have 9/10ths of a gallon of gas, right? Now this 9/10ths of a gallon of gas still cost $3. Now theoretically you need to buy another 10th of a gallon of gas which will cost you 30 cents. Now this gallon of gas costs you $3.30, plus the 10% ethanol in the 30 cents worth of gas. In the area I'm at, premium gas has no ethanol and is about 20 cents higher than ethanol gas. Just buy premium and save all the trouble. Even if premiun was 40 cents a gallon more. $3.40 a gallon compared to $3.30 the other way. If you did 10 gallons, is it worth all the hassle for a dollar? I understand if your area has premium with ethanol, then you wouldn't go the premium route. Hope I didn't confuse anyone. If so, let me know where you got lost and I will try to clear it up for you. I understand peoples frustrations and I'm not against anyone's idea of removing the ethanol for their small engines.

 

[JRC0528]

That's a good thought on the economics of it Monte... hadn't even considered it as I was one a one-track-mind thing there. Personally I've not had any trouble other than one old batch of 2-cycle mix that I attributed to ethanol, but many do seem to have trouble with it. As to disposing of the waste of the process, perhaps burn it off much as some used to do to get rid of used anti-freeze? Can't say it's environmentally friendly, but neither is dumping it!

 

[Reverend Blair]

Good test, Rog02. I now have an alternate use for that old beer-making equipment.

I've noticed a few 2 stroke manufacturers are having trouble because of the ethanol as well. Seems it keeps the oil in the mix from properly adhering to the metal parts so you lose lubrication and burn up the engine.

I know Makita was recommending using high octane fuel because it's less likely to contain alcohol, but as noted the octane rating is no guarantee.

 

[Torque454]

I always ask the clerk at the station if their premium fuel has ethanol or not. It isnt required in 91+ octane here in missouri, but some chains add it anyways. There is one station that specifically labels their pumps "contains no ethanol" on the 91 octane. That is the station I try to get fuel at as much as possible. Its a little inconvenient tho.