"...the tank's valve open cause we used it so often..."

Major no-no. It only takes seconds to turn the tank on or off...

Ya my mom made that mistake once and we found out right before grill time that the tank was completely mt. :-) No Problems, just shut it off after each use.

D

Maybe it's the storage circumstances. I have a couple cans in the garage of my cabin. The garage is under the building so under ground level. It never gets quite cold enough to freeze in winter, around 35F at the coldest and never gets warmer than the average basement. I know for a fact the one can is no less than 25 years old and it still burned fine in a lantern when the power was out in July.

I can't even think how old my can of Coleman fuel is. I bought it back when I actually backpacked, so that is on the order of 14+ years. The can was opened when I bought it to fill the aluminum bottle for my old whisperlite stove.

I was recently given an old Coleman lantern my Mom found at an auction in her neck of the woods. The carrying case for the lantern is steel - the thing is built like a battleship.

Filled with the fuel from the (now rusty, but not rusted through) can. Had to dismantle the pump and wipe some gunk off the leather, then was able to fire it up without any trouble.

I can offer up my experience with a 25 year old can that I inherited from my father. Seems no one else in the family is interested in camping and this can, which was purchased in the early 70s lived on a shelf in my folks garage for almost two decades.
When my father passed away, I inherited it. In the mid 90s I bought a Whisperlite Internationale to replace an old butane cartridge stove I had. In less time than it takes to talk about it, the stove was completely gummed up and burning very badly. I got sporadic flames. Lucky for me I had an Esbit stove as a backup lest it would have been a very cold and miserable wet night in the Pacific Northwest.
I don't know for sure how long the stuff lasts, but having a can around for four or five years hasn't caused any issues. I do tend to buy smaller cans these days, knowing they will eventually deteriorate after opening.

In our rough hunting camp we keep a 2-burner Coleman stove as back-up to the propane kitchen stove. One year we had to cook on the Coleman stove for a week as we had problems with the propane.

I do not know how old the Coleman fuel was (it was both in the tank and an open can), I would say over 5 years but less than 10 years. The stove burned poorly, it produced a yellow flame and smoked a lot. After we filled the tank with new fuel the stove ran great, with an efficient blue flame and little smoke.

Mike

Interesting experiences. Some people have had problems with old fuel, but many have not. I wonder if it's climate related? I live in Southern Calif. It's pretty dry here. I bought a one gallon can of Coleman Fuel (white gas) in about 1987. I'm still using it today, and I've had nary a problem. It's been stored in the back of my bedroom closet. Not sure that's the safest storage place, but as an apartment dweller, I don't have a lot of choices. I've had no problems in twenty years, so I suppose it isn't too unsafe.

I use the fuel for my old Whisperlite stove, also purchased in 1987. I don't use the stove a lot anymore which explains why I can go so long on one gallon of gas; I bought a Jet Boil relatively recently which is a lot easier to set up and use. I keep the Whisperlite for winter hikes. I also use the fuel for my two burner Coleman stove, but I don't car camp a lot. I mostly back pack.

I'd guess that it has to do with temperature changes. Your fuel is in a climate controlled environment. Many people store it in garages or sheds where temps can vary from -20 to 100 degrees F.

Well, actually, I live in the San Fernando Valley, which is a pretty hot place, and I don't run the air conditioner during the day while I'm at work. If it's in the 90's F in downtown Los Angeles, it'll often be over 100 F here in "The Valley." This fuel has been through years of high temperatures.

However, I do live in S. Calif, and I doubt very much that temperatures have been below 32 F (freezing in other words). I wonder if freezing temperatures would be more of an issue.

If nothing else, the S. Calif. dryness prevents the can from rusting.

"...the San Fernando Valley...I doubt very much that temperatures have been below 32 F..."

Not always. Dec/Jan of 1973 we had N/B I-5 closed at Roxford due to SNOW. Lots snow right there!!!