gasoline lifespan,without additive

[toolaholic]

Question on gasoline. I've got 90 gals. of gasoline in My motorhome. Been in there 2 ,maybe 3 years. Don't think I added stabelizer. Will this week. Start it once every 2 months to run engine and generator. Just how long before gas goes bad! Thanks' Tool

[Bird]

If it still starts and runs fairly well, I'd dump some Stabil in it and run it. But be aware that I'm talking about only my personal opinion and what I would do if it were me; no technical knowledge at all.

I've posted the following information before, but I'll repeat myself. In 1970, I bought a new 2 hp Johnson outboard motor to use on a canoe (and later on a jon boat). In the Fall of 1971, with short notice, I was sent to Northwestern University for the school year and that little outboard was left full of gas (2 stroke with oil mixed, of course). It was at least a year later in 1972 when I had an opportunity to use that motor again, it started easily and ran just fine, I thought. But when it ran out of gas and I dumped fresh gas in it, and restarted it and took off again, I'll bet the wide open throttle produced at least another 500 rpm.

The point being that the old gas worked, and worked pretty well, but fresh gas worked noticeably better.

[toolaholic]

Thank's Bird. Mom thinks' it might be good to have that 90 gals if there are problems someday.

[SkyPup]

Gas starts to oxidize and lose volatility in about two weeks, mostly dependent on the ambient temperature and exposure to the atomsphere. Be sure to add Stabil if you are not going to use it right away.

You do have to be extra careful with the new Ethanol additive gasolines as they goes bad even faster.

In addition, ethanol gasoline is especially bad for marine use as it destroys the rubber fuel pump bulb on outboard gas tanks in a hurry. In larger inboard fiberglass boat gas tanks the ethanol gas will completely destroy the tank......

[Flatheadyoungin]

with the price of gas, i'd smell it and then put it in my auto tank and then mix it with some good gas.....

call it a day....

[dieseldave56]

Gasoline can be stored from a couple of months to a couple of years , depending on storage conditions. The gas you buy at the pump

is a couple of days to a couple of months old from storage.

What makes gas go stale is evaporation, oxidation and contamination.
Usually the lighter , volitile chemicals evaporate first, leaving a less 'peppy' fuel. Less BTU.

The oxidation takes effect as oxygen reacts with hydrocarbons to produce varnish and gum. The fuel will smell sour and turn dark. Not a good idea to use fuel in this condition.

Contamination i.e water condensation, bacteria (from the water) and rust
( from the water as water settles to the bottom of the tank, your steel metal tank).

Ethanol , like California's reformulated fuel is reported by Chevron to store as well as pure gasoline, But ethanol is hydrophilic which attacts moisture from the air so theoretically it should become more easily contaminated than pure gasoline.

As for adding a stabilizer two years later , it is waste of money.

BTW, exercising your genset UNDERLOAD periodically for an hour or two is recommended, but NOT good for your motorhome's engine, as the engine or exhaust will not reach operating temperature . Thus fuel will pass by the rings , down the cylinder walls and into the crankcase, diluting and contaminating the oil. Unless you take the coach out on the road and bring the engine and running gear up to operating temps you are doing more harm than good.

[mrutkaus]

Use it up in other vehicles as soon as you can, you are on borrowed, lucky time!

Mike

[Bird]

BTW, exercising your genset UNDERLOAD periodically for an hour or two is recommended, but NOT good for your motorhome's engine, as the engine or exhaust will not reach operating temperature . Thus fuel will pass by the rings , down the cylinder walls and into the crankcase, diluting and contaminating the oil. Unless you take the coach out on the road and bring the engine and running gear up to operating temps you are doing more harm than good.

Very good information.

[toolaholic]

Thanks' all ! Very informative,Will mix this with fresh gas for use in My other vehicles. Then replace with fresh gas in M. Home.

Who makes a good transfer [fuel] pump ,for this job? Maybe I'll hit the whole hood, at O dark thirty ! Tanks Tool

[Skyco]

Stabil has come out with a new Marine formula for gasolines containing ethanol. Most reports are ethanol laden gas doesn't store as well as non ethanol containing gas..
The new Stabil is blue and costs twice as much