You can also call around local airports to look for ethanol free gas. Planes that have been modified to run on automotive fuel also cannot tolerate ethanol. Generally 100LL (100 octane low lead) is the easiest to find at airports, but some have automotive ethanol free fuel.

That's very good to know! We'll have to check out local airports if our ethanol-free gas station switches over.

Thanks for that bit of advice Mark. I believe you are talking about "Presleys" market, right? My friend John owns that place, and I always give him a hard time because his gas prices are usually a few cents higher than anywhere else in town. But since it is ethanol free, Ive come to realize, its worth paying a few cents extra. Many people also swear that ethanol free gasoline gets better miles per gallon.

I'm not sure which gas station Mark went to, but I'm intrigued to hear that ethanol lowers gas mileage. I'll have to read up on that!

Ethanol doesn't burn like normal alcohol therefore causing a performance decrease in any engine. Everyone I spoke with that have flex fuel vehicles don't recommend using e85 unless you drive locally because of having such a decrease in performance especially when towing! Ethanol also absorbs water just an fyi which can lower the octane rating by as much as I think 5points which can make some cars and trucks knock due to the low rating so if e10 sits in ur saw dump it out and put new stuff in cause it'll absorb the moisture in the air. Oh yea ethanol is harder on engines for instance they recommend changing oil on cars and trucks that run e85 to change their oil every 2000miles prolly due to the fact it has less lubrication properties since it's an alcohol compared to normal gasoline. So as far as I'm concerned they can put ethanol where the sun don't shine and come up with something better that doesn't smell like rotten eggs when it burns!

Good point! Thanks for that very useful information!

1) Aviation gas is designed to run at a constant load and differs significantly from automotive type fuel. Aircraft run at constant loads and have pilot controlled mixture adjustments. In cases with varying load, such as cars and small engines AvGas can cause detonation problems (early ignition of the fuel charge before its time, which can destroy an engine). With AvGas running close to $6 per gallon, I doubt this will be a good option anyway.

2) The reason that ethanol in fuel causes problems in older engines is primarily in the gaskets. Older gaskets may swell in the presence of alcohol. Swollen rubber parts may prevent the fuel pump from working. Even worse, they may constrict fuel passages, causing the engine to run lean and burning it up.

My background is in automotive engineering and I personally avoid ethanol diluted fuels whenever possible. In very modern cars, it may not be a problem, but older engines may suffer significantly. I recommend that you drive a little further and pay a little more for gasoline without ethanol.

Interesting pointer about the gaskets. Roland also pointed out on another post that ethanol won't mix with non-synthetic oils for two-stroke engines, which seems even more damning for the chainsaw. Since we're inclined to drive old clunkers, it sounds like we'd better take your advice.