Stored Ethanol gas-- maximum storage life

[James Landi]

Interested in your experiences with stored ethanol gas in a fuel tank over a lengthy time period... thanks James

[Cadman-iac]

James,

I have used fuel that I had stored in the car for a couple of years with an additive in it. I used Stabil fuel stabilizer.  But there are several others on the market as well.
I've also had fuel in cans that I've had for my mowers and tractor that have sat for several years with the additive in it and have had no problems yet.

HTH,
Rick

[Scot Minesinger]

I have used untreated standard premium pump gas three years old without issues.  It is rumored that standard premium lasts longer than regular.  I always buy 5 gallon spare tank fulls of premium, that way it can be used in a chainsaw with mix, my daily driver which uses regular or a high compression 1970 Cadillac.

[Jon S]

 I have had cars sitting two years plus with ethanol and no stabilizer and they start almost immediately with no problems. Do you think the government adds stabilizer to the millions of gallons they maintain in reserve?

[Cadman-iac]

I have had cars sitting two years plus with ethanol and no stabilizer and they start almost immediately with no problems. Do you think the government adds stabilizer to the millions of gallons they maintain in reserve?

That's a good point.  I have forgotten to add stabilizer to some fuel before,  and haven't had any problems with it either. Never really thought about that.
It's probably a sales gimmick because someone had an experience once with some bad fuel, so now they recommend it for all fuel.
Very good point.

[Caddyholic]

I use 2 stroke oil in my car tanks when I let is set for a long time. It has built in stabilizers. A quart to a tank is like 100 to 1 mix. I have chain saws, concrete saw, weed eaters that sit years at a time and they start right up. It  also coats the inside of the engine and exhaust system.

[64\/54Cadillacking]

I had fuel go bad in one of my stored Lincoln’s. The gas was probably a few months old and was very oxidized. The car would barely start and it ran like crap with the old gas. I needed to get the tank dropped and cleaned out, the shop added fresh fuel and afterwards the car ran so much better.

As far as stabilizers go, I tried Stabil and it didn’t seem to do anything in terms of keeping the gas fresh.

There’s a video on YouTube by someone that does all kinds of testing of oil and additives. It’s not scientific, but his work comes close, his channel is called Project Farm. He tested old fuel with 10% ethanol in his lawnmower , and the other one that was 100% fuel, and guess which one had the least amount energy loss? You guess it the 100% gas. Also the 10% ethanol caused a lot of corrosion on the metal plate he had submerged in the test bottle. It goes to show how quickly ethanol fuel oxidizes, loses its energy, and causes severe corrosion on all kinds of metal surfaces.

So it’s not good to leave any kind of gas too long in a fuel tank regardless if one uses a fuel stabilizer.

[cadillacmike68]

I have had cars sitting two years plus with ethanol and no stabilizer and they start almost immediately with no problems. Do you think the government adds stabilizer to the millions of gallons they maintain in reserve?

I don't think the SPR is refined product. And the way the military goes through fuel, they they don't need to super stabilize it. This was one of my logistics specialties, and there is a Very regular supply to operational forces, including direct from the refineries in some parts of the world. The only stuff that sits around for any length of time is at bases back here in CONUS.

[signart]

Temperature that the fuel is stored in can greatly affect the decline of the octane of your fuel. Cooler & drier environment will have much less affect, and yes higher octane declines at a lesser rate than lower octane. Plus, you have a higher octane to begin with, so one is better off to store with the highest octane available ( and corn-free).
I used to store my small engines and cycles, (one of which has 6 carbs), with aviation fuel over winter when I had connections at my small local airport, but that source has since dried up. That unleaded high octane would actually tune up a carburetor by fair weather time!

[TJ Hopland]

Art hit on what I was going to say.  I think the environment is really the biggest factor.  The actual formulation and additives do come into play but I don't think they are as important as the ambient conditions.   

What are the ambient temps and humidity and also another large factor is how fast does that change?   An uninsulated but fairly enclosed space could easily have a 50 degree swing day to night every day.   Insulated would likely have less of a swing and certainly slower maybe similar to just being 'outside' under a roof to keep direct sun off.    Climate controlled or underground where the temp hardly ever changes would be ideal.   

[James Landi]

Thanks to all for very sound advice--, and TJ, your post especially provides some hope that the fuel will be ok after two years, because the fuel tank is indoors-- unheated, but in Maine, where the temperature swings are, for the most part, rather gradual, so less apt to create moisture, (aka rain) in the fuel tank.   I have had issues with fuel separation and a bunch of invisible brown gunk plugging the low speed jets that only compressed air would remove...but that's from "corn fuel" evaporating in the carburetor... again thank you to all for your comments and sage advice,   James

[signart]

Actually, the easiest test is the smell test. Open the cap and take a wiff, if it doesn't smell like gasoline, siphon-drain, just get that stuff out of there and start it with fresh fuel.

[Jon S]

Actually, the easiest test is the smell test. Open the cap and take a wiff, if it doesn't smell like gasoline, siphon-drain, just get that stuff out of there and start it with fresh fuel.

The gasolines of today all smell bad. I remember the sweet smell of 101 octaine gasoline. Nothing comes close today.

[hornetball]

The gasolines of today all smell bad. I remember the sweet smell of 101 octaine gasoline. Nothing comes close today.

I still buy both race fuel and avgas from time to time.  Oh, how nice they smell!

[TJ Hopland]

I'm in an area where I can get non ethanol premium and in the summer I can easily tell the difference just by the smell.  I assume its to do with the humidity because its a lot more obvious when its really humid.  The premium kinda brings back memories on what I remember gas used to smell like.   Back in the days where people used gas as a universal solvent and even hand cleaner.   

[cadillacmike68]

The gasolines of today all smell bad. I remember the sweet smell of 101 octaine gasoline. Nothing comes close today.

Lead poisoning, anyone?

[hornetball]

Lead poisoning, anyone?

Yes, please.