How long can gas last?

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bill

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My wife has her "project car" (Sure Ain't A Bmw) which has been sitting unused for 2-3 years (it's a long story....) Do I have to worry about the gas being "bad" if I want to try to get it running again? Thanks for any advice.
 
I would just add new gas, 2-3 years isn’t bad. I’ve had gas older than that and it hadn’t turned to varnish. Using a fuel additive wouldn’t hurt.
 
My gas will be pushing 3 years. Car still starts and drives fine.

According to AMC, it lasts at least 10 years.

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If it ran well last time you should be ok, but if you're chasing issues put new gas in it.
You're ahead of the curve if you put rec gas in it, that stuff doesn't have ethanol in it and lasts longer.
 
Since it most likely has ethanol blended gas I would drain it rather than take a chance pushing it through the fuel system, unless you added a fuel stabilizer. I've always read ethanol blends have a 6 month shelf life.
 
A friend had a 735i with a bad head gasket, parked it for 7 years IIRC, then gave me about 12 gallons of fuel. After siphoning it through a tiny little filter, it worked in my lawnmower and I poured it through my K100RS Beemer with no ill effects. We have ambient temps in the 80s for much of the year, and relative humidity in the 70s-plus most of the time. I don't buy the "gas goes bad" line, though said mower did choke later on gas with water in it. I was too cheap to throw it out after disassembling the tiny carb once... so I had to do it again. Stubborn old man, when will you learn?
 
I suspect a lot depends on the humidity level where the car is stored. One contributor to fuel degradation is the absorption of moisture from the atmosphere, so it'll probably last longer in Death Valley than in New Orleans.
 
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jmackro said:
I suspect a lot depends on the humidity level where the car is stored. One contributor to fuel degradation is the absorption of moisture from the atmosphere. So it probably lasts longer in Death Valley than in New Orleans.
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I would also consider how tightly sealed the container/tank is that the gas is stored in. The volatile components of the fuel will evaporate pretty quickly in a container that is not relatively air tight, leaving something that closely resembles varnish.

I don't think you can make a generalization about how long gas will successfully keep. Too many variables.
 
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