Jim P

Jim P

Well Known Member
For those well-versed in fuels, I drained about 10 gallons of year old 18 month old 100LL from my other homebuilt (yea, I've been flying the snot out of the RV), and re-filled with newer fuel (ground runs haven't eaten up the fuel). I'm now trying to figure out what to do with the old fuel, can I add a couple gallons at a time to the new fuel to mix it up and consume it? I'm just looking for the best way to dispose of that older fuel.
 
Jim,

There was an article in either AOPA or EAA magazine a few years back on this subject. They said 100LL had a shelf life of two years.

They went on to say mogas is good for one year.
 
you could always add some to your car, make it around 10%-25% of the fuel and burn it up that way if you didn't want to put it in an airplane.

someone mentioned they use it in their lawnmower :)

edit, mixing it in the airplane sounds good tome, i was thinking if it was put in a modern car it could foul the O2 sensors if to much at once was used. an older car would probably love it. 10 gallons over a couple tanks in a car probably won't do anything, but on second thought i was thinking i better mention the o2 sensor fouling just in case.
 
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If I can find that article, I'd probably just mix a couple gallons at at a time in the RV since that that's been going through gas!
 
Danny7 said:
you could always add some to your car, make it around 10%-25% of the fuel and burn it up that way if you didn't want to put it in an airplane.

someone mentioned they use it in their lawnmower :)
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Bad idea, I did it and the lead in it tore up the catalytic converter.

Gary Specketer
 
Danny7 said:
ok, O2 sensors and catalytic converter. what exactly did the cat. do or not do anymore?
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The lead in the exhaust precipitates in the catalyst and eventually (more sooner than later) plugs it up. Lots of folks found this out the hard way back when both leaded and unleaded auto fuels were available.
 
The lead will coat the platinum/rhodium catalyst used in the catalytic converter, poisoning it and rendering it unable to convert the CO and unburned fuel to water vapor and CO2. There is a post-converter oxygen sensor that will recognize this problem and set a trouble flag on the main computer.
 
longranger said:
The lead in the exhaust precipitates in the catalyst and eventually (more sooner than later) plugs it up. Lots of folks found this out the hard way back when both leaded and unleaded auto fuels were available.
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Yeah, but what does that mean? The car runs a little rough? i thought the cat converter was in the exhaust and tried to burn up a little more of the exhaust products to produce a "cleaner" exhaust gas, but i kind of thought they stop working after a certain mileage without lead anyway, so does it make a difference in driving?

saw your post greg, thanks. how long do those converters last in normal use?
 
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100ll does indeed have a longer shelf life than mogas but the lead in it will destroy the cat in your car. So, if don't want a big bill for replacing thge cat do not put it in your car.

I would just add a couple of gallons to each tank of the RV to use it up.
 
Danny7 said:
Yeah, but what does that mean? The car runs a little rough? i thought the cat converter was in the exhaust and tried to burn up a little more of the exhaust products to produce a "cleaner" exhaust gas, but i kind of thought they stop working after a certain mileage without lead anyway, so does it make a difference in driving?

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When I said "plugs it up" that's what I meant. Engines don't run so well when the exhaust has no place to go.:rolleyes:
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Danny7 said:
saw your post greg, thanks. how long do those converters last in normal use?
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The old ones weren't so good, replaced a couple between 50k and 75k miles back in the late 80's, but I've had two pickups with converters run well into mid-200k miles with no problems and I've got 171k on my current one. The catalyst beds are a higher quality these days and last longer.
 
Vespa Fuel

As a hanger brat growing up in NZ my mentor and friend Con Pellow who taught me how to rivet on Beavers used to mix 50% avgas and 50% shell 55 which was a low grade cleaning petrol. He had the cleanest running Vespa in town.

Rob
 
Your car will fail state emissions inspection if you put as little as 5 gallons of 100LL in your tank. Ask me how I know :rolleyes: Then you will have to go buy an expensive replacement catalytic converter.
 
Jim,
Put it in your RV and go!! If you have any concerns, burn one tank down close to empty, add the "old" stuff and fill the tank. 2009 was a good vintage for 100LL!

N941WR said:
Jim,

There was an article in either AOPA or EAA magazine a few years back on this subject. They said 100LL had a shelf life of two years.

They went on to say mogas is good for one year.
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