RV gasoline life span in long term storage

[GrampaR123]

Due to health problems our motorhome has been stored unused for over a year. How long does gasoline last before it goes bad?

[turbojimmy]

Depends on the definition of "long term". My Allegro sat for 6 years in a tow yard with 80 gallons of gas in it. The guy that sold it to me said they added Stabil to it. I didn't want to run it through my new engine (the reason it was in a tow yard) so I siphoned it out 5 gallons at a time and burned it in my daily drivers. They ran fine with it.

The Allegro sits more than it's driven (like a lot of RVs). The gas I have in it now is almost a year old. I run it once a month and it's fine - always starts right up. I fill it with fresh fuel at the beginning of every season (late-Spring, early-Summer).

[Executive45]

Siphon it out, 5 gallons at a time. Put it in your car and use it up. Refill with fresh fuel and run it out about 100 miles. That will use up any old fuel. Don't overthink it.....Dennis

[JRscooby]

valhalla360 wrote:
How much fuel is in the tank?

If it's on "E", consider draining and disposing of the old fuel if you can get at the outlet easily.

Otherwise, you can dilute with fresh gas.

On the positive side, if it's a full tank of gas, you are less likely to get water in the fuel but be prepared to swap out filters if there is water in there.

Unless it's a really old MH, I expect it has fuel injection so the float bowl and carb jets gunking up are likely not an issue.

Might be worthwhile to siphon the level down to half or less, (lower is better) before you fill with fresh. If what you take out does not smell to bad mix with fresh in car that you can drive, but do not expect to demand peak performance.

[JRscooby]

jdc1 wrote:
You'll be fine. How long do those unwanted new cars on the lot sit before they drop the price in half?

How much gas do you think new cars have in them?

fitznj wrote:
I had a classic car that did not get driven too often (<150/year); it
had at least 2 year old gas in the tank and drove ok each time.

However - it sat unused for more than couple of years and the float bowl
and jets had a chalky residue which had to be cleaned out.

If you can; run the engine to operating - every once in a while and maybe
add fresh gas with seafoam.

My old cars I would normally put fresh gas in them every time I used it. Never fill, but enough to go and back.
I also put a valve in the fuel lines so I could shut off gas, and run the carb dry.
But I'm not sure that modern fuel systems are not more sensitive to old gas, or that the modern blends of gas keep that well.
The pickup I have now I make a point to drive some every week. When the gauge reads 1/4, I put in 5 gallons. Before I hook up to trailer, I fill the tank so over half is fresh. If it has been couple of months without using the trailer, I notice a decrease in mileage the first tank. Run down to 1/4, refill a couple times, better.

[ksg5000]

I had fuel injected vehicle sit for 2 years with no obvious problem. I rotate emergency gas stores on a yearly basis - no problems.

[valhalla360]

How much fuel is in the tank?

If it's on "E", consider draining and disposing of the old fuel if you can get at the outlet easily.

Otherwise, you can dilute with fresh gas.

On the positive side, if it's a full tank of gas, you are less likely to get water in the fuel but be prepared to swap out filters if there is water in there.

Unless it's a really old MH, I expect it has fuel injection so the float bowl and carb jets gunking up are likely not an issue.

[samsontdog]

Does not say what State it is stored in. If Calif I would not trust going over 60 days at the most unless you have Stabilizer or seafoam in the tank

[old_guy]

when I worked for big box store they always said 30 and it starts going bad. that is why in the spring they sell a ton of lawn mower carburetors

[wa8yxm]

THe answer is I DO NOT KNOW.. but I can tell you this.....

They say more than six months unless you stablize is asking for trouble

I know of a Workhorse 8.1L Fuel injected Vortec that sat for several years. So long the batteries were flat (Would not even taker a charge) Took 3 of us and the converter to bring in the slides. Dropped a new chassis battery in it turned the key and it fired up like I was in the dealer's showroom. Drove it around the campgroung a couple of times and parked it in the long term storage area for the cg owner (This was done with premission of the RV owner) Never misfired, not once.

Of course I also never hit 10 MPH

[fitznj]

I had a classic car that did not get driven too often (<150/year); it
had at least 2 year old gas in the tank and drove ok each time.

However - it sat unused for more than couple of years and the float bowl
and jets had a chalky residue which had to be cleaned out.

If you can; run the engine to operating - every once in a while and maybe
add fresh gas with seafoam.

[midnightsadie]

might be ok, pour a couple cans of sea foam in it and drive it around about twenty miles. then use that fuel up as soon as you can.

[jdc1]

You'll be fine. How long do those unwanted new cars on the lot sit before they drop the price in half?

[Dick_B]

Stabil states 2 years.

[Ductape]

Sorry to hear about your difficulties. Was any fuel stabilizer used prior to parking? If so, it’s probably OK, but I wouldn’t personally go past two years even with stabilizer.

If it was not treated, it depends on the conditions, temperature, humidity, how full the tank is. Over a year could be to the point of degrading already. If it was mine, I’d put some Techron fuel system cleaner and some octane boost in the tank and hope for the best. Probably that will get you through that gas and you can drive it out and get fresh gas.

It’s impossible to be certain of the situation until you get into it. Could be no problems; could need fuel filters, worst case it could need the tank dropped and drained.