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AV gas


Well-known member
Just wondering if anyone can tell me how long 100LL avgas will last being stored away? I have 15 gallons that is about 2 years old and I would hate to despose of it. Any help would be appreciated. Thanks


If it is in sealed steel container I can see it lasting 5 yrs or better. Keep airtight and in a cool place and it will do just fine. Hopefully it has been kept airtight tillnow. You could always sell it. I filled up at Immokalee Saturday and was $6.61g FYI


Well-known member
Several factors will effect the rate with which a fuel degrades.

Exposure to light
Exposure to air / moisture
Container material

Sunoco on their Race Fuel site states that highly refined Race Fuels can be stored up to 2 years if held in a proper container.

My advice would be before use smell it and look at it in a clear glass jar.

Slidin Gator

Well-known member
Store it in a container that blocks U-V light (the sun) and pretty much indefinitely. Water will settle in the tank but the fuel is good. I’m still sitting on 100 gallons I bought at $3.50/gallon last year, all good.

UV will cause the lead to precipitate out, then you would have to burn it in the lawnmower or mix in some ethanol to get the octane back up to run in your 87 octane car.


Well-known member
Thank you everyone for the information and advice. I appreciate it. I was thinking that I might mix the old 10 gallons with 10 new gallons and go from there. I will inspect each gallon of the old fuel in a glass container. Thanks again all.

terrible ted

Well-known member
Put it in my 1990 f150 it will run it. lawn mower wont Doesn't ignite good enough for my lawn mower. Smell and clarity My fuel has to be at least 2 years old Mechanic ran my boat when he redid my rings said the fuel seams fine.