I was watching a video about long-term storage of fuel for portable generators and the guy suggested buying racing fuel because it doesn't have ethanol in it. In case you didn't know almost all vehicular fuel in the USA contains 10% to 15% of ethanol. I already knew that ethanol breaks down rubber fuel-lines & gaskets far faster than fossil-fuels do, but he was making the point that pure fossil-fuel is hydrophobic (repels water) whereas ethanol is hydroscopic (attracts & absorbs water) and as time goes on more & more water will be drawn to ethanol left sitting in your gas tank. And so he suggested buying racing-fuel to keep stored for using in your portable generator because it will 'keep' for much longer. But racing fuel is usually 107 octane and costs a fair penny. There is a website that lists every gas station in the USA or CANADA that sells "pure" fossil-fuel not mixed with ethanol. Sometimes it's even offered in 90 & 93 octane, although the most common is 87. Anyway, here it is: https://www.pure-gas.org/ Click on your state or province at the bottom and it will list every station sorted by city along with the octane of NON-ethanol fuel they sell.
And this was the video which got me thinking about it:

 

100% gas with a little Sta-Bil in it - and I could store the lawn mower and slowblower for MONTHS with no issues.
My dad refused to believe in Sta-Bil and often had awful times starting small engines after storage.

I live in rural Arkansas, 100% gas is easy to find here, at least 91 and higher is.

 

We have Shell 91 and 93 around and 91 is what I use. Why use the mixed crap?

 

180, you need to switch to Petro Can Ultra 94
definitely worth the few cents more a litre

 

It contains up to 10% ethanol, so I do not use it.

 

Yeah, alcohol in gasoline is such a bad idea. Besides being hygroscopic It diminishes the power and reduces gas mileage.
As for pizzaguy's message on sta-bil and the like, it is my understanding that alcohol in the fuel de-activates it and here's why:

Fuel preservative additives such as sta-bil "float" on the surface of the fuel. Effectively sealing the surface and preventing the evaporation of the contained aerosols. Aerosols are the explosive components of gasoline. 30 percent of gasoline is additives from the supplier. Once the aerosols are gone you are left with something that smells and eventually looks like varnish; the solidified additives.. In effect, alcohol breaks down the floating substance designed to prevent evaporation and exposes the aerosols to the atmosphere within the container.
Please correct me where I am wrong on this..

 

I think this is the best product on the market to actually fight phase separation of the Ethanol . . . Star Tron Enzyme Fuel Treatment Gas Additive Small Engine (starbrite.com)

Daniel

 

The point being is that alcohol in your gasoline renders the fuel "stabilizer" inert, not the other way around..