Why 2 Strokes Don't Like Ethanol

How long had that gas or gas mix been sitting in your can? Was it open to the air or sealed?

Alcohol can dissolve in water and it can dissolve in petroleum, but wet alcohol tends to separate from petroleum.

Try it again with fresh gas right from the pump and make sure there is no water in your alcohol. (and use a different glass!)

Drew K

The gas was fairly fresh and in a sealed container.

Mixed the 2 stroke oil in right away...followed with the denatured alcohol from a sealed can, that I use for stove fuel.

I did a quick search but couldn't find a composition of stove fuel, there could be water in that.

Drew K

It's just denatured alcohol. Stove fuel was the wrong term...I use it with a fondue pot.

All it is, is pure alcohol with poison added to it to make sure that I don't drink it without paying taxes on it. I have to go to the liquor store to get the non-poisonous stuff.

And you said the government has no place in private enterprise.

We call that Metho in Oz. Short for methylated spirits.

A bit of methanol is what's added to make it toxic for the same tax reasons.

Apparently if it is mixed with boot polish or beetroot juice it's good to drink. The tipple of choice for park dwellers there.

Add a single drop of washing up liquid, stir it, and see what happens...

I did it.

The separation happened faster; the alcohol is cleaner, and the gas/oil mix is beginning to take on the characteristics of a lava lamp, but not as pronounced.

Welcome to Two Phase Flow 101!

Is either phase combustible, BTW?

The local hardware store has a repair department for lawn and garden equipment, and it is piled with work.

Yes. Both phases burned nicely.

I think the problems come when the mix is run through tiny carburetors.

So that's where tcmtech has gone!

In the circumstances it does seem inappropriate to mix ethanol, gasoline and 2-stroke oil.

Where is PlbMak when advice is needed?

I used up the last of my ethanol 2 stroke mix, in the chainsaw, which it didn't like...and switched to non-ethanol gas. It's a much happier little machine; as am I.

How were you able to find non-ethanol gas? To the best of my knowledge, in California the "summer blend" all contain 10% ethanol. I don't remember ever seeing a station that sold anything but that mixture. (possibly due to the CARB~~California Air Resources Board. Then again, the California legislature, representing the fruits and nuts, has already passed a carbon tax law)

We do have numerous small airports where 115 octane Aviation gasoline could possibly be purchased, although I suspect that would burn a little hotter than 87 and 92 octane and might require adjusting the timing or jetting a bit. Also more expensive!!

Being in CA, I'm surprised they haven't outlawed gasoline altogether.

Non-ethanol is becoming pretty common around here, although it's kept expensive enough to prevent people from using it in their cars.

You can check these sites:

http://www.fuel-testers.com/find_ethanol_free_gasoline.html

I only see 5 in CA, but you may consider looking at boat marinas; they should have ethanol free gas, but won't be listed as stations.

I think we need a chemist in this discussion. I only know the littlest bit in how water, alcohol and fuels mix.

It is my suspicion that the soap is trying to break down or combine the long chain hydrocarbons in the fuel causing heavier waxes to develop.

Drew K

My lawnmower is 4 stroke, and has no problem with ethanol gas...even if it's been sitting for a few weeks.

ethanol is great at sucking up any available(including through the air) water if you give it a chance, need I say more? those clouds in your mix aren't a fluke

I don't think the cloudiness is from water, but I could be wrong. The denatured alcohol came from a tightly sealed can, and I get a nice blue flame from it when I use it as stove fuel...no orange flame or popping sounds from water content.

The alcohol seems to change the viscosity of the gas/oil mix, making it "thicker". Between that and the separation, it's no wonder that the little air driven diaphragm fuel pumps have a hard time with it...not to mention the tiny ports that it has to move through.

In my chainsaw, the mix has to go through this, before it even makes it to the carb.

Might explain why the fuel lines tend to collapse.

The ethanol mixed in gas makes the two stroke run leaner. Today's cars have a computer to make correction. These small engines don't. You can adjust the mixture to get it to run better to normal. Most people don't. The consequences is a lean engine runs hotter. And the cooling fins on the engine were design to dissipate the heat from running gasoline. The extra heat is what is detrimental to the engine.

Buy your gas mid summer and put Store & Start in it.

I'm going to stick with small batches of non-ethanol gas.

Using the ethanol stuff in two strokes, it's not a problem of them getting too hot...it's about keeping them running period.

I just went with the 4 stroke....more torque, lower rev's, no mixing, 1 gas container...

I didn't even know they existed for lawn equipment.

http://www.amazon.com/Makita-BHX2500CA-Commercial-4-Stroke-Compliant/dp/B001ASHLSU/ref=sr_1_2?ie=UTF8&qid=1383150373&sr=8-2&keywords=4+stroke+chainsaw

Can't find a chainsaw though.

The're coming, Makita has one....

http://prolandscapermagazine.com/makita-showcase-4-stroke-outdoor-power-equipment-at-lamma-2013-show/

They've been flying for years:

4-Stroke Engines

I think it was a B 17 model that I saw, 10 years ago.

Use to work on equipment that had engines designed to run on gasoline. They were converted to LPG on the new equipment by the equipment manufacture. LPG would also like the ethanol blended gas cause the engine to run at elevated temperatures. There were frequent heat gasket failures in the engines. As the design didn't allow for addition thermal expansion between head bolt and head. Cause by the higher temperature the engine would run on LPG. The problem was so bad the engine manufacture pull out. This is after working with the OEM to design a emission control system. Emission standards opposed by many cities necessary to meet use for running the engine in relatively closed space indoors. At the time it was the only machine that would make the emission standards.

Not only are they running leaner, but in a 2 stroke engine, (even if the alcohol contains no water), if there is a phase separation between the gas/oil, and the alcohol, the engine will be running from primarily alcohol from the bottom of the tank...which would provide almost zero lubrication for the rings...which would make it run hotter and increase wear.

Interesting:

http://www.redlineoil.com/product.aspx?pid=91&pcid=16

Sounds like the right stuff.

From what I'm seeing on the internet, the cloudiness is caused by the alcohol reacting with the oil, and causing it to form into microscopic globules.

Based on this map, getting ethanol-free gas might be a challenge depending on where you live. Other sites with maps are linked at this web site. The maps don't always agree. And as the article at that link states, the only way to confirm for sure is to test it.

Being in Central Texas there aren't any. Actually, it is curios to ponder the maps. Why so much in the eastern half of the country and much fewer in the western half. Geographical reasons? There are "requirements" for gas in different regions (map). Who would have thought gas would be characterized as a "boutique" formulation. And overlaying the requirements map on the ethanol-free map is a bit confusing. If requirements are law how do ethanol-free stations exist in regions "requiring" ethanol blends? Even more confusing, it appears there are seasonal blends, too.

One explanation (and there may be more) for ethanol's detrimental effect on small engines is here, saying it is grit in ethanol-based fuels that is the culprit. And this video on YouTube demonstrates a fairly easy test. The guy also mentions the solvency issue.

I bought a new lawn mower about 5 years ago and right about that time saw a thread where you, kramarat, mentioned it's harmful effects you were seeing on your lawn equipment. I immediately switched to the in-between octane (3 grades, typically sold at pumps in Texas) and so far so good. But it probably also has some ethanol in it, just maybe not as much. After 5 years it's a bit late to test it, but I probably will now. I don't see that you really need a graduated cylinder to see the ethanol portion. I was just now looking for whether or not even the middle grade has ethanol in it and can't seem to find a link yet. I guess the "requirements" might dictate ethanol in all grades depending on where one lives.

Sheesh! I never thought about this much before.

My 4 stroke mower doesn't have much of a problem with ethanol.

Fortunately, I have a station right around the corner that sells ethanol free gas. I've also started using it in my boat, which is a four stroke, but the carb is a pretty precise unit with extremely tiny ports in it. It does not like ethanol.

You're probably wasting your money on the mid grade gas for the mower. The ethanol content is the same as the 87, so just use what it calls for...which is probably the regular.

I'm not sure if I buy the "grit" theory. Alcohol is distilled; where's the grit coming from?

Plus, the super fine filter on my chainsaw would stop any grit from getting to the engine.

You're probably right about the grit theory. Maybe more Internet babble. This short article, while not specific as to how the damage occurs, is at least from a national vendor (Tractor Supply). Also, here is a preliminary report from the DOE in 2009 about the problem. The upshot shows little forward thinking.

Forward thinking?

I'll try to constrain myself from flying into a full blown rant.

Thanks for the the link....and thank you US government and DOA. You've been a great help. A*&%oles!

From the link:

In some situations, ethanol/gasoline blends might absorb water vapor from the atmosphere,

leading to phase separation. Such problems are of greater concern for engines with open-vented

fuel tanks that are operated in humid environments, such as marine engines.

.......

Additionally, more complex phenomena such as lubricating oil/fuel separation (in 2-stroke

engines) and temperature-induced phase separation of various fuel components have also been

noted.

I, too, have several thoughts about the preliminary comments by Dr. Ron Sahu, on the preliminary report by the DOE. Sorry. I incorrectly described the contents at the link. My comments, too, might be considered a rant. Later perhaps. Even so, would any change come from it? No.

I will go through that link in more detail, and post what's wrong with it.

They were obviously told to paint ethanol in the best light possible; and it fully illustrates how government is willing to manipulate science to fit an agenda.

Download the full white paper.

Wonderful. The first paragraph has me pissed off.

You did this on purpose.

Hey,

They at least told the truth.

You know what I'd really like to see?

Full financial disclosure statements, (including investment portfolios), for every Washington politician, (both parties), going back 40 years.

I don't think there would be any question about who screwed everything up.

...and a full of audit of any inherited wealth.

This is a generational problem....sleaze is a hereditary trait.

Good find!

I went through the entire thing, and can't find anything good about using ethanol.

Thanks Jimmy Carter.

I run my old tractors on E30 and I can assure you that once you go from the normal grades of gas to a higher ethanol content one for what ever reason it really does a good job of breaking up the old gasoline varnish and surface rust in the tanks.

I just picked out a old MF 202 industrial forklift that sat for a number of years and put its first full tank of E30 in a few days ago.

The first tank of fuel I ran through it was regular gasoline and I didn't have any trouble with much crud coming out of the tank however after the next fill up with all E30 that was a whole new issue.

I made it about 20 minutes of run time before the new fuel filter was full of rust, the sediment bowl had a half an inch of varnish and rust flakes in the bottom and the neck of the sediment bowl assy had plugged solid.

I ended up taking the whole tank off and flushing it with the diesel fuel I had used to flush the transmission out with last week. I dumped it through a old rag to catch the junk as it cam out of the fuel tank. I got about two full cups of rust and varnish grit out of the tank!

It's been running great the last few days but I am still seeing a slow build up of fine flakes in the sediment bowl and the fuel has a very slight rust orange tint to it now so I suspect more rust and varnish are dissolving again.

Yeah. My Craftsman mower has been running ethanol gas since I bought it used, 10 years ago. One thing I did this summer, that it seemed to like, was to change the oil to full synthetic.

I think there is a definite problem with using ethanol in the two stroke mixes. The cloudiness is something that I've noticed for a long time.

I used to work on a tank farm in Georgia. The gasoline that passed through my tanks had an octane rating in the 60's. Ethanol is added at the terminals as it is shipped out to the petrol stations bringing the octane rating up to the normal 80's we se at the pumps. Most petrol stations only have two tanks of gasoline, premium and low grade. The pumps mix the two with a blend ratio to make the mid-grade. All of them have ethanol unless you are at a petrol station that purchases ethanol free fuel.

The seasonal blends are an effort to limit evaporative emissions. If you consider the temperature of fuel in tanks that are free vented the warm summer temperatures cause more evaporation. Now consider all the petrol stations in a city, with all of them venting constantly...it ads up to significant pollution. So summer blends of fuel are designed to have a lower vapor pressure and vent off less.

There are geographic restrictions also, what they call non-attainment zones where year round they have to use the lower vapor pressure blends.

Funny thing I alwasy laughed at was at the tank farm, we didn't care who the fuel belonged to. While it was in our custody, we would mix batches of fuel from different companies in the same tank, or swap one batch for another if we wanted to let it sit to remove water.

It is quite the complex system.

Drew K

Interesting.

We have 8 weed eaters, 4 blowers, three chain saws and 3 lawn mowers where I work. I don't have to use any of them. The mowers are 4 stroke.

We have them serviced at a shop that does nothing else but sell and service landscaping equipment.

The old grizzled owner told us to use at least the intermediate grade of gas and nothing but Echo _{(usual disclaimer)} two stroke oil. I don't know where we could get alcohol free gas, even if we wanted it.

I'll take his word for it.

I think they might not have as much of a problem if they are in regular use. Echo's confidence in ethanol blends doesn't sound quite so confident. But they do add fuel stabilizers to the oil.

http://www.echo-usa.com/Warranty/Learn-About-Ethanol

All our power tools are Echo. (usual disclosure) We never keep more than a one week supply of gas on hand.

I have the luxury of buying new equpiment when I think we need it. Our golf carts (5) and pickups (3) are on a mostly regular replacement schedule.

You also live in a much drier climate than I do, which may help prevent fouling. Our summer humidity can get very swampy. 70-80%.

Does it say ethanol, ethyl alcohol or methanol on the bottle. In Frankfurt they use mostly methanol for fondue sets. Methanol doesn't mix to well. Ethanol does and so does isoprophyl alcohol (Propanol)

According to wiki, denatured alcohol is ethanol with a dash of methanol and some other things.

https://en.wikipedia.org/wiki/Denatured_alcohol

Here where it's pretty dry, I use reg unleaded with ethanol in my 2 stroke string trimmer. I'm pretty bad about mixing oil and gas - I let it sit for months or in this case, a year and a half. When I pour the gas into the trimmer fuel tank, it looks pretty good. No gunky or cloudy stuff.

I think climate has a lot to do with it. Today, we're at 51% humidity (humid for this time of year). Normally during the summer, a humid day is about the same as today's and a normal day is around 30%. Maybe this is why we don't have problems with our ethanol gas. Also, I haven't seen non-ethanol gas at any stations, so I don't think it's available here.

Here in Indiana we try to find a fueling station near an airport there is usually one or two that sell non alcohol fuels for airport equipment. Or I purchase all of my chainsaw fuel from tractor Supply or Rural King in 1 gal or 5 gal cans sealed with no ethanol as my Stiel chainsaws hate alcohol with a passion. The grit you are probably finding is possibly casting material from the magnesium cases seeing as magnesium does not like alcohol at all. I did find signs of surface degradation in the ports of the carb. As all 5 of my saws did not want to start this fall I had to replace two carbs all together and rebuild the rest I will not use ethanol ever again. Only stiel gas premixed or Tru- fuel from TSC from here on out . Duke

As I understand it, alcohol absorbs water of of the air quite readily. This is why you'll have trouble finding pure alcohol that is higher than 90-95%. Even straight grain never gets better than 190 proof.

To get higher alcohol concentrations one needs to add other organic compounds to reduce the propensity for the combination to absorb water. I'm told that benzene and toluene are used for that purpose. It's not likely that either is used in readily available commercial gasoline blends and I couldn't tell you what's in there. I'm neither a chemist nor do I work at a refinery.

No, you won't be able to mix denatured alcohol with gasoline. It's already absorbed too much water. The mix in commercial fuel is probably done with alcohol that is 'dried', as noted above, with other chemicals. The process would avoid water intrusion into the mix and make the alcohol blend more easily.

Dry-Gas is a mix of alcohol and something else (other organic compound) to help disperse the water. Try your experiment using a bottle of Dry-Gas and see what happens.

I suspect that the Dry-Gas, (being alcohol), would have the same reaction with the oil in the 2 stroke mix. From what I've read, there is just an inherent, (chemical), compatibility problem between oil and alcohol.

PROOF!!!!

I know...I boosted the alcohol content, but I think I've just accelerated the process that takes place anyway, and fouls 2 stroke engines...

I took regular 10% ethanol gas and added some of the same denatured alcohol:

It looks slightly separated, but it's not. It's a uniform amber color.

I added a drop of food coloring to show the even mix:

All is uniform. The lighter color on the bottom of the glass is due to reflected light.

I then added just a dash of 2 stroke engine oil, gave it a good stir to get an even mix...and here's what I had less than a minute later:

No more ethanol in my small engines or boat...not as long as I have a choice.

Update:

I posted the picture of the phase separation, this morning at 8:40 AM. It is now about 3:40 PM. I just got back from cutting wood, and the clear blue alcohol in the bottom of the glass is almost gone.

I think the reason for eliminating the vents on gas cans, was not because of water intrusion, but because the alcohol evaporates off, leaving gasoline with an octane rating in the 60s.

I also think this is the reason behind the boat problems; the tanks are open vented.

For anyone that's interested in the molecular chemical explanation for the phase separation:

The structure of an alcohol resembles that of water. With both alcohol and water, the bond angles reflect the effect of electron repulsion and increasing steric bulk of the substituents on the central oxygen.

http://chemwiki.ucdavis.edu/Organic_Chemistry/Alcohols/Properties_of_Alcohols

Neither mixes well with oil.

If you're using gasoline with any level of Ethanol in it for your 2-cycle and 4-cycle equipment, then you should be using the MARINE grade Sta-Bil fuel treatment. It prevents the Ethanol from dissolving the internal plastic parts in the fuel system and carb. Ethanol acts as a SOLVENT!!!!!!

DO NOT USE THE OLD REGULAR STA-BIL; IT WILL NOT PREVENT THE ETHANOL FROM ATTACKING THE PLASTIC PARTS! I found this out talking to my local power equipment distributor friend a few months ago. Using this additive will eliminate very cost repairs and equipment replacement. This info have been verified by my kid brother, who is a Chief Chemical Engineer working Castrol BP.

http://petelandrysrealgas.com/2013/02/why-marine-formula-sta-bil-should-be-your-fuel-additive-of-choice/

Would post mix 2stroke engines take to ethanol more favorably.

I can see how separation of premix in the fuel tank could lead to no lubrication.

Post mix systems will still get the oil into the engine.

Any opinions?

I would think so.

I haven't looked closely at these systems, but if the oil and gas are atomized separately, and injected into the firing chamber, I think it would provide adequate lubrication.

On a side note...I think there have been a lot of problems with boat engines. When we were vacationing at the beach this year, I noticed that every station had a dedicated ethanol-free pump, right alongside the others at each pump island.

Into the firing chamber?

Not a two stoke diesel. That's another animal altogether.

I think we're talking about two stroke, "gasoline" fueled, fuel mist lubricated, spark ignition engines. (Right? I sometimes forget what I'm ranting about) The fuel/air/oil mix is drawn into the crankcase and then ported up into the combustion chamber as the piston comes down and opens a port.

Common on 2 stroke motor bikes. Especially motorcross bikes.

You have to watch the oil level in the reservoir as well as what you have in the fuel tank. Running out of fuel makes for a long walk, running out of oil is terminal. A bit of 2 stroke oil in the fuel tank as well provides a bit of insurance, hopefully the engine will start to pinch giving you time to stop before it totally fuses.

(Except for just one outlet in front of a new ethanol distillery here) The gasoline at all other fuel retailers/wholesalers here does not contain any ethanol. I figure it won't be long before it does start appearing at their pumps as well though. Common in Thailand now. ( They have "lotus flower scented smoke" 2stroke oil too. Nice)

One more potential disaster to look out for coming my way I guess. Life was once so simple...

No, not a diesel. The extent of my knowledge, is that I know they exist. I saw an ad for the new 2 stroke Mercury outboard motors, that keep the gas and oil separate until combustion.

It saves the trouble of mixing, but I still don't think ethanol fuel belongs anywhere near a boat.

After reading the links that lyn and passerby put up, I can't see any reason for us to be using ethanol at all. It looks like a net loss, and nothing but political BS.

Not only might it be causing more pollution that causes respiratory problems, but I came across a link yesterday that dealt with the danger to emergency responders, when they come across fire that involves ethanol. The gasoline burns off first, leaving the alcohol...which burns clear, is hard to see, and has burnt people responding to accidents.

I got one reason for ethanol. Fresh sunlight. Oil is fossilized sunlight that has been underground for a very long time and is now being extracted for the energy that the plants and organisms liberated from sunlight. Ethanol may not be as dense of an energy source but it is using fresh sunlight.

How much longer do you guess we can keep using the fossilized energy? Eventually what is left will become too expensive to extract. Working toward using different energy sources now is a good idea. Making new cars capable of running on ethanol is not a bad idea.

If we want the same power from a machine using a less dense energy source it will have to be more efficient or bigger. I would like to see people working on new types of engines, multi fuel turbines, internal or external combustion steam combinations, hybrid, electric and the like.

Drew K

I don't necessarily disagree, but I think you should look into the fossil fuels that are burned in the production and distribution of ethanol. It's not insubstantial, and it has to be included in the equation...if we're going to be honest.

True, but it will change as the fossiles get more expensive. I would love to see solar powered equipment harvesting, processing and disributing the ethanol.

Drew K

Don't get me wrong; I'd love to be able to completely eliminate fossil fuels...I just don't think that mixing ethanol with gasoline has any impact whatsoever, and if it does, it's a negative one.

every station had a dedicated ethanol-free pump, right alongside the others at each pump island.

Like this:

The ethanol is hydrophilic and separated from the other organic solvents in the gasoline/oil mixture which is hydrophobic. There is a limit to the alcohols allowed in gasoline as dispensed but I don't know if the limits were established with the oil blend considered. The alcohols do attack older vehicle fuel systems as the rubber compounds were not selected to resist alcohols. The alcohol and low boiling solvent components vary seasonally to maintain similar Reid vapor pressure for operating gasoline engines well.

I had noticed the cloudiness of the two stroke mix before, but I always attributed it to water intrusion that had been absorbed by the alcohol. Not any more.

I've been cutting a lot of wood lately, and there is a big difference in how my chainsaw runs with the non-ethanol gasoline.

Welcome to the forum.

There will be a difference because alchohol has alower energy density. I notice a 2 mpg difference in my truck when I fill with ethanol vs non ethanol. I have started calculating the $/mile of my truck with each fuel and choosing the best when filling up.

Drew K

True, but my four stroke lawnmower doesn't care. Other than getting less hours out of ethanol, it runs and idles fine. Not so with the two stroke stuff.

I think there is some separation due to the oil/alcohol combination; as well as the oil coming out of solution and forming tiny globules...which makes it cloudy.

Check out "white gas" in a Google search. It is an unleaded gasoline without any additives, and has a much better storage life than regular pump gasoline or ethanol added gasoline.

White gas, Coleman fuel and Unleaded Gasoline are all related in that all of them are of a similar boiling points and are distilled from petroleum from the same 'cut'. Gasoline is more broad in the 'cut' and has a wider range of materials in it. It also has additives that make it store less well.

This has been a very interesting thread!!!

Are you sure about additives in petrol that shorten the shelf life? Sounds kinda strange...I'll take your word for it though.

I have some old petrol stored at home that is so dead I can safely use it as fire starter. Burns about as fast as diesel so no singed eyebrows.

Dead petrol has a signature smell to it...or is it something missing that changes the signature?

Dead petrol is petrol that's lost its kick. It's impossible to start a motor bike with it. It doesn't have to be totally dead either to really ruin a day.

Agreed, I've learned a bit on this thread too.

I Googled Coleman Fuel/White Gas to get to the article. It references an article found at 'Frugals'

In paraphrasing the article "Gasoline is more broad in the 'cut' and has a wider range of materials in it. It also has additives that make it store less well."

"Gasoline more than a year old is marginal. Store it for a couple of years and it will smell of varnish and have odd deposits on the bottom of the can".

Whenever I finish using my 2 stroke weed eater, blower, or chainsaw, I empty the gas tank and restart the engine to run the gas out of the carb. When the engine dies, I use the choke to restart them to insure that all of the gas is out of the carb.

That method seems to work very well for preventing a buildup of varnish in the carb.

This interested me because I needed to buy some fuel for a Coleman stove and Lantern. An older gentleman suggested buying "white gas". I just couldn't find any and had to spring for the $10/gallon Coleman fuel. OUCH!!!

White gas, (Naptha), would probably work, although it would be pretty expensive. It's the basis for gasoline.

My next question would be...Why would the government force additives into gasoline that cause it to have a short shelf life...with ethanol making it shorter yet?

I might be mixing my memories here. I have worked with jet fuel (military and civilian) and ground fuels. I think some of the additives help conductivity so that static that builds up in the pipeline (it really does) can be released to the tank walls. Some of the additives are designed to help engines, some reduce evaporation and most importantly, they raise the octane rating of the gas so it will burn smoothly in your car.

Drew K

Drew do you know what the octane modifiers were/are. and can they be added to white gas to help with octane deficiencies to run in a chain saw or other equipment. Duke

Hold the train!

If this is accurate, white gas has far too low of an octane rating to replace gasoline.

http://en.wikipedia.org/wiki/Coleman_fuel

The gas in the pipeline ran at octane ratings in the 60's when ethanol is added at the terminal as the trucks are loaded it is raised to high grade and low grade, the pumps at the petrol stations mix the two grades to make a mid grade.

It would take someone with more experience than me to modify the blend ratios of a gasoline of known octane with an ethanol to raise it. I worked on the pipeline and not the terminal so I don't know what blend ratio they used.

Drew K

I was thinking along the lines of tetraethel lead , toluene, or xylene these have been several items that I have seen used for octane boosters in the past and there are others. Thanks, Duke