E 10 fuel...mixing with non ethanol

[SmokyMtnGrady]

Hey yall:
I have not followed the ethanol issue until I joined the forum here last year. I was reading on THT the issues of E 10 and separation. I also read never to mix the 2 fuels. I searched here and on THT. I read it is bad, but I honestly do not know why because folks just state it as a fact like gravity or the sky is blue.

I have a minor in chemistry and E 10 and unleaded are both hydrocarbons. They both burn. The old saying goes the solution to pollution is dilution. I am not a petroleum guru, so if anyone knows the real reason as to not mix the fuel types could you enlighten me? I am afraid I have mixed them without giving it any thought. Thanks.[/i]

 

[87offshore24]

There will be no problem with mixing the two.

 

[richie rich]

SMG...what fuels are you talking about...E-10 and ?

pretty much all fuels these days are E-10...that is 90% unleaded fuel with 10% ethanol.....your motor is most likely not rated for anything above 10% ethanol...it may run rough if you do so....what you don't want to mix with ethanol is old school MBTE oxygenated gas with E-10......those 2 don't like each other and will cause more than just phase seperation in the tank.....you'll get hard orange gels clogging up your fuel system big time....been there, done that......so other than those 2....just use good gas stabilizer like marine stabil and a quality Racor style filter and you should be good to go...if you have an old tank that used MBTE...I'd have it cleaned out before running E-10

 

[Doc Stressor]

You will be OK as long as there is little or no moisture in your fuel tank.

Water is not miscible with straight gasoline. So condensation from atmospheric water vapor can accumulate at the bottom of the tank. Adding E10 to a wet fuel tank can result in phase separation where the water phase will contain most of the ethanol. Since ethanol is used to increase the octane level of the fuel as well as an oxygenate, the octane level of the gasoline phase can drop below that which is required for proper engine operation. Pre-ignition can occur and damage the power head.

Phase separation can also occur when straight gas is added to a tank with wet E10. E10 can hold up to about 0.5% water without the phases separating. But the amount of water that can be held in solution is a function of the concentration of ethanol. So if you add half of a tank of straight gasoline to E10 that contains say 0.4% water, the ethanol concentration drops to 5% and phase separation will take place.

The bottom line is that if your fuel is dry, you shouldn't have problems. However, it is not a good idea to store mixed E10 and gasoline since the lowered ethanol concentration will make the tank more prone to separation. There is an internet rumor that ethanol and MTBE can react to form a precipitate if they are stored together. However, I don't know of a reason for a chemical reaction between these compounds.

 

[richie rich]

Doc.

it's not the mixing of the 2 per se, it's the cause and effect......when using the MBTE fuel for many years...it leaves a residue inside your tank....when you switch to E-10, the ethanol acts as a solvent and literally cleans your tank...when that happens, the residue breaks down into gels and clogs your fuel system...I have had that problem along with many other boaters.....so its not a chemical reaction....but more a cleansing reaction that causes trouble for older boats....

 

[Doc Stressor]

I agree with that completely.

I think the rumor that MBTE and ethanol interact likely comes from solvent related problems as you have described.

While ethanol will eventually dissolve varnish, it first causes it to flake off surfaces and become suspended in the fuel.

E10 problems usually go away over time with continued use of ethanol containing fuel. Varnish deposits eventually get dissolved or removed after changing the fuel filter a few times. Running more E10 is the best way to remove water from a tank as well. I'd be willing to bet that a lot of snake oil fuel additives have been given credit for solving ethanol problems that went away by themselves after continued use of fresh E10.

 

[richie rich]

Bingo. The snake oils made their rounds for sure. After 3 years of expensive filter changes every fill up and poor performance I eventually ended up getting new tanks. The cleansing effect became too much for my motors(maybe me actually) to handle. It was not a warm and fuzzy going out on the water with the system choking mid stream. When i cut up my tanks to recycle I found about half the varnish still lining the inside of the aluminum. Now its all fresh. Thank the big guy for sure.

 

[hotajax]

Mixing Fuels

No chemist here, that's for sure. But I was using the E-10 for several years, then my marina started selling ethanol-Free gas. The result? The boat runs way better than it did before. It is much much happier, and has had no problems with the mix initially.

 

[Doc Stressor]

My F150 picked up 300 rpm at top speed after my marina switched back to straight gas last fall. I haven't measured mid range full consumption yet, but I anticipate that has increased as well.

I had no problems when Florida first started selling E10 two years ago and no problems when I mixed the fuels after my marina switched back.

If you can get non-E10 fuel, use it. If not, just stick with E10, use a fuel stabilizer, and keep your tank close to full.

If you have been following the E10 vs boats stories on the web, you may have noticed that most of the problems occurred right after a particular area switched over. After a year or so, the reports of ethanol problems become much less frequent.

 

[richie rich]

Which brand is making/selling E-free gas? I have not seen that up in the Northeast......what's the octane rating?

 

[Parthery]

Only places around here that are selling non-E10 fuel are the marinas that sell Valvtect fuels.

Their website has a list of marinas which either sell non-E10 fuel, or sell E10 fuel that hast been treated with stabilizers.

A quick search of their website (http://www.valvtect.com/marina_search.asp) will tell you if there is a marina near you.

 

[Strikezone]

My marina sells non-ethanol fuel so I've not had any issues.

 

[Doc Stressor]

Here is some info on sources:

http://pure-gas.org/

http://www.buyrealgas.com/

It doesn't look good for Connecticut, Rich. New England states have higher anti-pollution standards than many other parts of the country. These require higher levels of oxygenates in the fuel and ethanol is the cheapest way to go now that MTBE has been phased out.

We have a number of stations in Florida that carry all grades of ethanol free fuel. My marina carries something labeled "Low Ethanol Fuel", which they insist is ethanol free. It has 88 octane posted on the pump. Most other marinas use either Marathon 90 or 91 octane fuel of the Valvetec stuff. A local station in Crystal River, which is located near the public ramps and marinas sells ethanol free gas that is supposedly provided by Shell.

Gasoline is not mixed with ethanol until it reaches a local distribution center. The gas out of the pipe or tanker is usually 84-85 octane. So ethanol or some other oxygenate/octane enhancer needs to be added. This is often done at the tanker delivery truck, since each brand uses its own additive package. In areas with a lot of marinas, a distributor can decide to provide ethanol free fuel by the tanker load. But they need to have a number of stations or marinas in the same area to agree to sell the fuel before this becomes economically feasible.

The ethanol free fuel that you can find at small airports is not appropriate for use in marine engines.

 

[richie rich]

Yeah, I read about the ethanol mixing in the tanker.....who's to say they put in exactly 10% either......even my snowblower gas soured over the winter....didn't add the Stabil..DOH!.........just have to live with it.....you FLA guys get year round boating and the good gas.....not fair!

 

[SmokyMtnGrady]

Guys,
I am talking about E 10 and nonethanol fuels. Am I to assume the fuel with no ethanol is mtbe fuel? If this is the case I have used ethanol free marina fuel from time to time as needed, like last summer on Lake Hartwell or at Port St. Joe, but most of the time I fill up at the bp near my house. I have yet to notice a problem with my 4 stroke yammy.

If I have a gel gummy issue, how do I check it? Do I go through the tanks acccess ports topside or will it be evident in the filters? Thanks.

 

[richie rich]

SMG,
the gel problems I had were from the E10 dissolving years worth of varnish left behind from running MTBE fuels.....since you're running mostly E10 and once in a while MTBE (if thats the case) you shouldn't get that kind of a buildup......other than the engine not running well, at the most inappropriate time, you will see small orange gels in the small filter/screen on the engine (at least on my 2S Yammy) and possibly at the bottom of your Racors looking glass bowls.....MTBE fuels are normally listed on the pump just like E10 is listed on the pump.....if not, I'd ask the marina/fill station to be sure. From what Doc says, you may not have an issue in your neck of the country.

 

[gwwannabe]

Here in VA on the Chesapeake Bay, many of the marinas have non-ethanol gas. That said, I have a big problem paying over a $1.50 a gallon premium for the priviledge. I did buy one tankful last fall and noticed not one bit of difference at all.

Thanks to this thread, I now can understand the recommendation to not mix ethanol and non-ethanol based gasolines. What I don't understand is this... As the percentage of ethanol decreases and the percentage of non-ethanol gas increases, why can't you add the old fashioned dry gas to absorb the water?

Gary 89 Overnighter

 

[Doc Stressor]

Dry Gas and other related products are just alcohol. Either isopropanol or methanol (HEET). They don't do anything that adding more E10 would do.

100 gallons of E10 can hold up to 2 quarts of water in solution. Adding a pint of Dry Gas can hold about 1 pint of water in solution when added to straight gas.

Most engine manufactures recommend against using Dry Gas or the equivalent products to E10 since in can result in fuel with more than 10% alcohol. Marine engines have not been certified for fuel with more than 10% alcohol. Plus, methanol can turn acidic in the presence of water and cause all sorts of damage.

 

[SmokyMtnGrady]

Thanks..once again, y'all come through. I admit my own ignorance with this topic. Seeing the real potential for head aches, one would think if you buy a new boat or new used boat from a dealer, the dealers or marine association would offer these kinds of tips, especially to those buying a boat on trailer.

It is better to avoid a problem than to fix it....