Old gasoline - can it be used?

I have several cans, maybe 15 gallons of gas several years old. Fuel stabilizer was added initially.
I’d like to use it if possible so I can refill with fresh. Can i add a couple gallons of the old to an almost full tank of fresh in my Taco. Obviously if I see chunks or water in it I wont. But if it looks ok what could go wrong, especially diluted? Too much risk?
I’ve overhauled small engine carbs so know what old gas can do.
Or maybe I could test it to see if I can start a chainsaw first.

 

Several as in 3 years or several as in, You aren't sure? I am going to go with no on either. The reward isn't worth the risk imo, take it to a shop that burns it for heat and call it a day.

 

I don't typically risk it with new stuff with higher compression, but my old 9:1 compression land cruiser that would probably run on coffee and popcorn farts, sure I'll dump a few gallons of old gas in, it's a 26 gals tank, lots to dilute

 

I wouldn't reccomend it, like @ColoradoTJ said the shelf life of today's gasoline is 3-6 months even with stabilizer.
It's bad enough that if you let anything sit for more than few months the gas in it goes to crap and screws up the fuel system, no way I'd put 2 year old gas in anything unless it was an emergency/last resort.
If it is ethanol free gas it might still be ok up to a year but I don't think I'd risk it if it's 2 years old.

I have multiple ATVs and small engines and anything that isn't used constantly is nothing but headaches with crap ethanol blended gas.
I started buying ethanol free gas for anything I don't use regularly, it's almost double the cost of regular but it stores much longer without going bad.

 

The only experience I've had with ethanol free gas was negative. My truck ran poorly and got 2-3 mpg worse than normal. They sell so little of it that the odds are very good that what you get out of the tank is old when you buy it. I use regular 10% ethanol gas in everything. My lawnmowers, weed eaters, generators, and leaf blower, and chain saws start on the 2nd or 3rd pull of the rope.

The key is to not let varnish build up in the carburetor. Even when not using them I will start the engine and let it run for about 5 minutes every month or 2. If there is a fuel cut-off valve shut off the fuel and let it run until it runs out of gas. Doing that keeps the carburetor clean and trouble free.

I have an ATV but don't drive it often. I filled the tank over a year ago and still have 1/4 tank. It starts and runs fine. Fuel injectors are much more tolerant than carburetors.

Pouring in 2-3 gallons at a time mixed with a full tank of fresh fuel won't hurt anything. No point in wasting $50 in fuel.

 

The place I get it from sells quite a bit, alot of antique vehicle owners buy it as well as others that use it in chainsaws and weedeaters.

Maybe in a dry climate it's not so bad but we have high humidity here 6-9 months out of the year and the ethanol just sucks up water out of the air, settles to the bottom along with the water, and corrodes aluminum parts.
Stabilizer helps a bit but not much as you can see in the video below.
https://youtu.be/UvS_D4_lF5U

 

Can be used to start the burn pile.

 

You could probably get away with adding a gallon to a 3/4 full tank so it gets diluted. Just keep doing that until you run out

 

Run it, 5 gallons to a 3/4 fill. Or give it away.

 

I'll echo what everyone else says - probably not worth it given the risks. Everyone has already given most of the valid reasons. But for sake of argument I'll throw math on the pile because who doesn't love some math on a friday? Anyhoo, my amateur Googling says gasoline is about $9/gal in Vancouver. Times 15 gallons and you got a grand total of $135 USD worth of old fuel.

Option A: Roll the dice on running the old fuel, congrats it works and you save $135. No way to quantify what it did for the longevity of your Tacoma but hey you saved $135!
Option B: Roll the dice and old fuel hurts something in your system. What's a fuel pump cost? How bout injectors? Do you want to find out? I wouldn't.

Let us know how it works out!

 

Lawnmower fuel...

 

What kind of cans? I regularly use gas up to 18 months old that has been treated and stored in my nonvented NATO cans with no issue.

 

If I was stuck in the middle of nowhere or I had to fill up my POS shitbox to get to work I'd do it. Otherwise use some for chainsaw fuel and throw the rest on the burn pile for a nice kaboom.

 

OP here.
I can’t see how the fuel pump could be affected since old gas is still liquid.
And same with the injectors.
I’m guessing the only potential problems could be temporary loss of power or mpg to some degree, or worse case some varnish buildup in the cylinders (totally guessing - anyone ever see something like that?)
What else could happen?

 

I recently put 2.5 gallons of year-old gas in my truck with half a tank. I, too, was concerned with water in the gas. I poured old gas into a clean plastic 1-gallon jug first, to look for water and debris. It was all clean, and no water. Truck ran normal but I didn't take notice of mpg. I have read old gas loses effectiveness.

 

I would mix it with my drain oil to be burned. Dump it in my 1000 gallon diesel tank if it was due to be filled not likely with current prices .

To me mixing a gallon with fresh gas in a vehicle would be very time consuming .

 

I’ve never seen that issue happen with “old gas” on EFI engines. Carbs will gum up but the fuel pump will just pass it through. Remember the solution to pollution is dilution, so put a little at a time

 

Truck? Wouldn't risk it.
Lawn-mower? Possibly.

Fire starter, definitely.

 

I don't think adding a gallon to a nearly full tank in a vehicle will hurt anything. Small engines (lawn mowers, weed eaters and small bore motorcycles) will be more affected by old fuel than car and truck engines. I would add a water treatment if you think there's any chance of water being in the fuel. And burn the last bit of fuel. All the crap sits on the bottom of the can. That's where you'll get problems from, if any.

I found it interesting when I did research years ago about storing fuel, ethanol and additives. Briggs and Stratton is the world's largest small engine manufacturer, and their recommendation was to add about an ounce of Marvel Mystery Oil for every gallon of gas to keep fuel from going bad and fouling carbs. Not Ethanol treatment, or Seafoam, etc... But, Marvel Mystery Oil.

I was already using it in a '92 S10 with regular octane to stop knocking of predetination and better fuel economy, so I started adding it to my portable generators and other small engine equipment. It also ups the lubricity, so that's a good thing too. Probably can't hurt to add some MMO if you plan on using it.

Otherwise, I've poured bad gas into gallon paint cans, put them in the fire pit and lit them. It slowly burns off.