Ethanol fuel or Aviation fuel

Usually AV gas has a bunch of stuff in iy dictated by the FAA. That addiyional stuff is not evident in the label on the pump. My thought is go with puregas.com.

 

I copied this from a forum I moderate on;

Ethanol is completely water soluble, that's why it causes so many issues in small engine carbs. Gasoline (without ethanol) is not water soluble. Use that to your advantage. Just pour a cup or two of clean water into a gallon of 10% ethanol gasoline from your local gas station. Then stir and mix it together vigorously for a minute or two. The ethanol will quickly separate from the gasoline and dissolve into the water. Then let it all rest. After 20-30 minutes of resting the new ethanol/water mixture will now be sitting on the bottom of the gas can because it is heavier than the gasoline. The pure gasoline should now also be clear again and easy to see through. That is how you know all the ethanol/water mixture has finished settling out of the gasoline. Then pour the pure (zero ethanol) gasoline off the top and you are good to go for whatever the going price per gallon is at the pump plus 10% to account for the ethanol loss. If you did it right you should end up with .9 gallons of pure gasoline since the .1 gallon of ethanol is now in the water.

I do this in 5 gallon batches for all my small engines. I use a large 6 gallon glass carboy so it is easy to see the clarity of the gasoline after settling. It is really easy and much cheaper than hassling with the ethanol free stuff. Last but not least, don't forget to add the premix oil at the end if you are going to be using the pure gasoline in a 2-stroke.

 

Lots of great info, Thanks a lot guys. I'm having all new problems now. Just burned up piston on my 372 tonight. 260 quit and won't start. 350 seems like it's over heating. Tore them apart, not Happy! They were all running fine 2 weeks ago. It's like sabotage or something. 1 saw acting up maybe, 3 at once? Had to be fuel related....?!?!

 

They had been smoking a little, mix was a little oil rich than I normally run, 35:1

 

Several articles around on the lack of quality control at the distribution points where the ethanol is added to the fuel, many reports of what is supposed to be 10% coming in at numbers approaching 28% on down. Newer saws are set way to lean to make EPA regs, plus the cat mufflers, and the poor fuel adds up to saws running way too hot and burned out in a short time. Just replaced the oil pump assembly on a makita 6421- plastic parts were melted- Home depot cast off so ya know it was abused.

 

OK I will. I've been up all night wondering what the could have happened. I've been running multiple saws for over 20 years, daily on the job site. Never seen anything like it. I'm no saw tech guru, but I'm stumped. Start one in the morning.
Thanks

 

28% changes a lot over 5-10%. I make and use biodiesel in trucks and tractors. I use methanol instead of ethanol, but I test my fuel batches often. Fuel quality and trace amounts of methanol can vastly change the function and performance. Ethanol % in gas has to be similar.

 

Ive ran from 87 to sunoco 110. Depends on compression as to a gain in performance. So far its shown with higher compression, the higher octane can be alil faster. It will be a few days but a friend of mine is having his MM 660 dynoed with 91 octane and sunoco 110. Vp94 premixed fuel is very good in most saws and is mixed from VP with motul 710 oil

 

I believe its the other way around actually - which is one reason some guys give for running it in saw. Avgas is more tightly regulated than auto fuel, its not allowed to contain any ethanol, and I believe has fewer additives. Its more carefully refined for a more consistent and lower vapor pressure (which means its less likely to evaporate/boil off - important for high altitude use in aviation where their is risk of vapor lock due to low air pressure in the tanks). If it where not for the dye, 100LL would actually be as crystal clear as water, similar to Coleman fuel. It has a longer shelf life than auto gas.

The main beef I have with using avgas, as mentioned above is the lead content. I looked up some specs... The below I believe is TEL concentration - 1 gram of TEL = 0.6 grams of pure lead.

modern unleaded gas = 0.001 grams/gal TEL
leaded gas at phaseout in 1986 = 0.1 g/Gal
leaded gas in the 70s = up to 1.0 g/Gal

avgas:
100LL = 1-2 g/Gal
100/130 = 4 g /Gal (this was the precursor to 100LL, and was introduced in the 40s for warbirds and high performance commercial aircraft)
115/145 = 4.5-5 g/Gal (WWII spec now only made in limited batches for airshows)
100/150 = 6+ g/Gal (high performance WWII spec no longer made)

The 145 and 150 grades have so much lead that in combat fighter engines had to have the plugs changed every 25-50 hours to combat lead fouling.


Interestingly there where a bunch of other avgas grades made including lower blends like 80/87 that are very similar to auto gas in terms of octane. Many light planes you see at your local county airport like Cessna's and Pipers would actually run fine on the 87 avgas since they are relatively low compression.. but the industry just decided to standardize on the single 100LL blend for consistency... there is not enough volume in avgas usage to make it worthwhile to refine multiple grades anymore.

The other thing to understand is that avgas measures octane different than auto fuel does. The avgas standard gives 2 numbers - the lower number is measured at moderate power in cruising conditions fully leaned, and the second number is for takeoff power under full throttle/full boost and full rich mixture. 100LL is effectively the same as 100/130 just with less lead. From what I read the lean number is fairly close to the R+M/2 figure for auto gas. so 100LL is about like 100 octane race gas, and 115/145 is basically 115.

Even more confusing is that auto gas is reported differently. You know where use the R+M/2 method here in the states... but many European countries just use the research number. So our 92 octane premium is sold as "98 octane" in Germany for example. And our 87 octane regular is sold as "92" in Germany. I think this is part of the reason some saw manuals call for high octane, but yet people manage to run them find on regular or even 55 octane Coleman.... They probably just translated the Stihl German manual direct to English and used the German octane numbers, which just happen to be the common regular grade available over there (just my guess, i have no evidence to support this!)

 

Agreed - I'd like to see those articles. If they where really letting 28% ethanol into the gas it would be causing a lot of problems with the fuel systems in people cars - problems that automakers would be refusing to repair under warranty. The brand new truck I just bought very clearly states in the manual and on the gas cap that E10 is ok but even E15 is a big NO-NO.

 

I have heard the 20% ethanol thing too

 

I have heard of people getting 25% ethanol when they test pump gas. I don't buy much gas besides for the saw. My truck is diesel. I may try some 110 here soon in a saw I'm working on. It may or may not be beneficial but we'll see.

 

I just bought some NON E last weekend 87 octane for like $3.35ish a gallon. They sell out all year long here and saws ran perfect on it mixed 32:1 with husky xp oil

 

How are they testing for the ehtanol? Using hte water trick mentioned above and measuring volume or some other method?


Id love to burn ethanol free in my vehicles and gear but according to puregas the closes station to me that has it is an hour away

I have been dosing every can I fill with Stabil for years and that really seems to help. I hear even better things about using marine Stabil or Seafoam - anyone use those? experiences?

 

I never treat any fuel. It doesn't last long though. We have 8-10 stations within a half hour with non ethanol.

 

I'm non ethanol from here on out, or as long as it's available in the US. Because it's a bad idea to phase out all non ethanol fuel, the feds will do it. Bought 91 for $3.99 yesterday.

 

Same here. We r lucky in central la as 87 non ethanol is plentiful but 91 and 93 is less readily available but still can be gotten within 30 minutes. I usually stock up on 91 when I travel out of town

 

We have 87around here E free for $3.35-3.60/ gallon and 93 octane for around $3.60-4.00 gallon. I only burn in in 2 stroke lawnmowers sometimes, at and boat. I use the e10 stuff in cars trucks as it won't last more than a week or two...sometimes months though in big brown but never a problem with it.

I use lots of sea foam...I like it but other thancleaning iI dont use it to extend fuel.