How long does it take for gas to go bad?

[sluggermike]

Because of things beyond my control, I have not been able to use my MH for ten months.  I occasionally drive it for a few miles, but not far.  I run the engine about once a month along with the generator.  i've never had a problem starting it even though the last time I filled the tank was about ten months ago.  I'm concerned one of these days my gas will go bad.  I've used Sta-Bil in small engines but never in the MH.  Any thought on this?

 

[glockholiday]

If it's not feasible to drive around for a day to use up some gas to refill with fresh. I've siphoned gas out of my RV into cans and put it in my daily drivers and filled my RV back up with fresh from the cans.  At 10 months that would be high on my to do list. 

 

[Gary RV_Wizard]

Modern gasoline is quite stable (due to chemical additives) and odds are you will have no problems. The fuel companies say that 6-12 months should be fine, despite the popular wisdom that "old" gas is no good.  However, beyond about 6 months the risks of a fuel deterioration problem begin to increase. Factors such as humidity, how full the tank is, and tank interior condition are a factor, so it is impossible to make any meaningful prognosis. I've kept fuel over a year with no problems at all, but that's not a guarantee that you can do the same.

There is no reason not to use a stabilizer such as Sta-bil. Can't hurt and might help.

 

[John From Detroit]

Gasoline, by itself 4-6 months is about as long as I'd care to let it sit, at 10 you are pushing it.

Gasoline with Sta-Bil. a year is just fine

Add Sta-Bil now, and if possible drive it around a bit to slosh the fuel and mix it in well, also re-fill the tank cause... Well, winter is coming and you never know when the power company will let you down and the only 120vac will be courtesy of Mr. Onan's (Or whomever) contribution to your motor home.

 

[Ernie n Tara]

I'd not worry about it. I've got a car thats up to two years now (I start it each time we stop at the "storage facility") and still starts and runs fine. I did add Stabilwhen I first parked it.

Ernie

 

[Jeff]

Most of the issues I notice have to do with the generator carb getting gummed up. They seem far more  susceptible  to bad fuel that RV engines. Making sure you run the generator every month will help.

 

[Gary RV_Wizard]

That happens when the gas evaporates in the carb from lack of use. It's not the fuel "going bad".

 

[sluggermike]

Thanks for the help.  I will look into adding Sta Bil when i top off the tank this week. 

 

[DailyDriver]

Slugger, I can't tell what part of the country you live in, but as Gary said environmental conditions have a strong influence on how long gas will last.  I had a boat that sat in Utah (relatively cool with medium humidity) for almost 3 years, without Stabil, and it was fine.  I didn't do that intentionally, it was due to circumstances beyond my control.  However, I always kept the tank full while in storage. 

I have a 65 Mustang in my garage now that has gas nearly 3 years old in it, with Stabil added.  When I fired it up about a month ago, it ran fine.  That gas has sat through 3 summers of AZ heat with relatively low humidity.  I wouldn't worry about it.  Some people think if your gas gets a year old it needs to be replaced.  My experience indicates that's completely wrong, though you do need to keep the tank full and hopefully add Stabil.  But, thanks for reminding me, since I really need to address the aging gas in the old Ford..!  I can't see pushing it much past the amount of time it's been in there.  I think it's time for a road trip.  (see attachment) 8)