Does gasoline lost its volatility if it just sits around? Reason I ask is

[raccoon]

I just read a post-apocalyptic novel where the gas supposedly was still usable after sitting in the
gas pumps for about 22 years.

[LiberalLoner]

1. Some properties (anti-static additive, etc.) do degrade but it's still gasoline.

[Ikonoklast]

2. The more volatile molecular elements that make up gasoline will vaporize over time.

Gasoline is also anhydrous, it tends to suck moisture out of the air.

Unless stored in a sealed container with an inert atmosphere, 22 yr. old gasoline is sludge.

[Iggy]

6. How do we know?

any research done on this?

I've had gas sitting in basic sealed containers for four years... still works great in
the chain saw and lawnmower

[Ikonoklast]

7. There is degradation of octane number over time.

In small internal combustion motors, not a big deal, old gas will still work.

In higher-compresssion fuel-injected or turbocharged transport motors, detonation due to low-octane knock can destroy that motor.

[Iggy]

9. Any available, store bought additives

one can purchase to remedy this problem?

[Ikonoklast]

15. I use Sta-Bil, and have had very good results with it.

http://www.goldeagle.com/brands/stabil/default.aspx

[Iggy]

23. OK Cool

thanks for this info!

[Ilsa]

14. Does propane last longer?

I realize it is for different purposes, but does it have a much longer shelf life?

[belcffub]

17. I do not think propane brakes down...

so it should last until all of it slowly seeps out of the tank...

[MercutioATC]

3. Simple answer: Yes, gasoline does degrade.

There are many variables, but gasoline always degrades.

Will it still burn after 22 years? Yes.

Will it work in a car with modern emission controls? Not very well, if at all.

[Trillo]

4. If typical retail gasoline sits in a gas tank for long enough, it will not run an engine.

I'm not sure if that means it "lost its volatility". When the gasoline goes bad, its odor changes. I've read somewhere long ago that the government used some kind of preservative to allow longer storage.

[leveymg]

5. If you want to keep gasoline for more than six months, or so, you have to add a chemical stabilizer

that will extend its usable storage life out to several years. But, no, I doubt gasoline will be usable after 20 years.

Try running a lawn mower with year old gas, and see what happens. It'll run, maybe, but not very well.

Diesel fuel has a longer storage life (5-10 years).

[pipoman]

8. Stabil should be used in gasoline which will be sitting around

http://www.goldeagle.com/brands/stabil/default.aspx

I use it in all seasonal equipment fuel systems. Before I started using it, each spring when I get the mower out the remaining gasoline would cause sluggish performance...same with my generator. Since I've been using it, my engines start and run after 6 months as if I put them away the day before..

[1-Old-Man]

10. This is something I've had a whole lot of experience with

You can store gasoline for up to a year without using stabilizer but if you plan to store it for any longer than that you need to add a stabilizer to it. I have used stabilized gas that was two years old, but I've never tried any that had been stored longer than that.

[Gman]

11. All I know is the times I left gas in my mower

over the winter, I couldn't get it started until I dumped the old gas and poured in fresh gas.

[HopeHoops]

13. Water in the line. Pretty typical.

[ProfessorGAC]

21. You Got Lucky, If That's All You Did

It wasn't the gas in the can, i suspect. It was the polymerization of aldehydes and carboxylic acids in the carburetor that plugs things up. The new gas might have just been barely enough to help dissolve the residue and start your mower.

In a gas can, it takes decades to build up enough of these to cause major problems. In the tiny areas of a lawn mower carburetor, the surface per unit mass exposed to oxygen is huge. So, the residue form faster and in tiny ports that will clog.

The stabilizers in gas are, in fact, anti-oxidants, which retard the oxidation reactions of the double bonds along the carbon chain. There just is too much surface area, too much oxygen exposre for those to help much once it's nearly in the engine.

[Gman]

32. Makes sense in that

here in S Texas, the last time I mow is usually between Christmas and New Year's (mulching leaves) and the end of February when the grass is getting shaggy enough to mow.

I neglected to mention this in my post. It's usually not more than 60 - 75 days between the last "winter" and the first spring mows.

[HopeHoops]

12. It's still viable as long as it isn't mixed with oil (two-cycle fuel).

The older it is, the less it will stretch, but it will still get an engine running and keep it running. Two-cycle fuel degrades rather quickly. If it's older than three years, get fresh and find a way to get rid of the old stuff (not easy).

[Javaman]

16. Which book?

I'm a post-apocalypse book geek.

[raccoon]

18. EARTH ABIDES, published 1949. Great book.

When I first read it in 1971, I read it within 24 hours. Couldn't put it down.

I re-read it recently. Still a great read, although some attitudes were dated. (And the gasoline wouldn't
still be usable after 22 years.)

[Javaman]

19. Oh ugh. We'll have to differ on that book.

I thought it was horrible. LOL

I could go into explicid detail but I'll just refer you to my amazon review.

Cheers!

"I had been really looking forward to this book. Sadly, it really didn't deliver. I found the story telling very linear, the main character Ish, lacking in any real depth and the logic of how he and his small band of people survived, very questionable.

I found the first 1/3 of the book interesting. The main character Ish, travels the US in search of other survivers of the deadly plague that ravenged the world. It read more as a travel logue than an sci-fi book, but never the less, was still interesting. However, one would be better served reading the book, "A world without us".

Ish, seems nonplused by the vanishing of humanity. The character uses "logic" to deal with the situation, but calls those who are enotional or "crazy" as being in shock. Frankly, it appeared to me that Ish was in shock, due to his lack of emotion over the loss of basically everyone. It was as if he rationalized it this way, "wow, everyones gone, oh well, I'm lonely, but that's the breaks".

Finally, gathering enough other stragglers together to form "the tribe", they seem to live solely on old can goods from local markers for...22 years!!. I don't know about you, but the last thing I would eat was a can of food that was 22 years old.

It appears as if everyone in the "tribe" was hit with the stupid stick. Any normal parent would teach their kids the basics of reading and writing, not these folks, it's as if they all just gave up. Plus there is a point in the story where it's highlighted that none of the children even know numbers! WTF? Any normal parent teaches their kids how to count their freaking fingers and toes!

Also, the book was written in 1947, yet no one in the book knows a thing about gardening! No one had victory gardens during the war? No one lived on ration cards?

It's like all these people dropped out of the sky.

There are some many other things wrong with this book, I could go on for pages.

Why did I give it 3 stars? 1 for it was a post apocolypic story, the second for the first 1/3 was okay, and lastly, the 3rd star because there were some mildly interesting moments.

Beyond that, it's like a group of morons running around in a dark room trying to find the switch."

[Brother Buzz]

22. Earth Abides is a grand book for the target reader - teens

I read three of Stewart's books in my teens: Fire, Storm, and Earth Abides. I re-read two of them in my adult life (Fire and Earth Abides), and well, they were not as exciting and engaging as when I was a kid. I guess the same could be said for all the wonderful Disney movies I loved as a kid.

[raccoon]

26. The canned goods business, I agree there. It would be tasteless if not dangerous.

IMO, the author was at his best when telling about the environment, how things would fall apart over time,
how livestock and animals fared after the demise of most of humanity.

I think another point the author was trying to make was that most people are about the average.

[ProfessorGAC]

20. Only Sort Of

Because of the unsaturation in the chains, gas will undergo mild oxidation when exposed to the atmosphere for a long time.

It will form some varnishes, aldehydes, ketones, and carboxylates. But, since those are still going to be low molecular weight, they'll still burn. They won't be as flammable, but still very combustible.

Gas used to varnish much worse, but the distillation processes have improved to the point that the lighter "enes" are lower in concentration.

Since aldehydes and acids can polymerize, you can get some filming. That's why a lawn mower might not start in the spring if you've left gas in the carborator all winter. The little orifice can get plugged with the varnish and the polymers. But a bulk storage of gasonline won't form enough of that to matter much.

GAC

[HooptieWagon]

24. Yes, when my lawnmover sits over the winter...

I have to throw out any old gas in the can and take apart and clean the carb. And a friend has an antique Honda motorcycle he only rides once a month, and has continuing fuel issues. A lot of it is the ethanol, but even pure gas goes bad

[gregoire]

30. Sad to see someone mention the ridiculous ethanol conspriacy theory here

Anti-ethanol people are everywhere.

[HooptieWagon]

31. Personal experience, not conspiracy.

My pickup loses 1 (about 5%) mpg when I fill up with ethanol blend. I repeated test over and over, and am confident of that conclusion. In vintage vehicles (which I own a few cars and motorcycles) ethanol plays havoc on the rubber parts in the fuel system. In boats, ethanol attacks fiberglass fuel tanks, turning them into a gooey mess that fouls the entire fuel system...ethanol is often used as a less toxic than acetone solvent for cleaning tools used in fiberglass work. Ethanol price is propped up in the US, it costs more than the gas its replacing. Using corn to produce ethanol raises food prices... not only is the corn itself more expensive, but livestock feed based on corn raises meat prices. All in all, ethanol production boosts profits for BigAgCo, but otherwise has few benefits.

[HiPointDem]

33. thanks, very interesting. all the gasoline i see here has ethanol. i don't know where to get 100%

gas.

i was wondering about why -- i think it's just a subsidy to corn producers, a way to get rid of their surplus.

[malthaussen]

25. I wonder how that applies to C-Rats and other preserved food

Somewhere there is probably lots of data on shelf-life of consumables, including food, combustibles, even probably laundry detergent. I remember my high school having stuff stored up for use in the event of a holocaust, and wondered then how often it had to be cycled, or if with typical bureaucratic shortsightedness they figured it would last forever...

-- Mal

[Callmecrazy]

27. I remember eating C-Rations back in 1985 that were

dated July 1963. Baked beans and meatballs. The meatballs looked and tasted like Alpo in gravy. But overall the food was fine.

[malthaussen]

29. Yeah, I had C's in the '70s that went back to the Korean War.

Tasted fine to me, but I was 17 years old. Everything tastes good to a 17 year old guy.

-- Mal

[One_Life_To_Give]

28. Going to depend upon which gasoline it is?

Ethanol Blend
Methanol Blend
Straight Gas obtained by Catalytic Cracking
Straight Gas obtained by Thermal Cracking
Temperature Blend of the fuel (January in Minnesota blend vs Texas in August blend)