Does gas get "stale"?

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Apr 13, 2013
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Haven't been driving much lately but the Accord in particular has had the same tank of gas in it for nearly 8 wks.

Is that a problem? Does gas turn "stale"?
 
LOL ... 8 weeks ... forget about it. I've fired up and ran vehicles with 1+ year old gas and there were no issues. Gasoline today is way more stable than it was 20+ years ago.
 
It can....

93 octane I have read is stable for up to 9 months to a year...

87 is stable for 4-5 maybe 6 months...


8 weeks if the gas was good when put in... Obviously should be just fine like Zee said.

The rationale I have heard for going to a busy station is that there is zero chance of the gas being old aka stale... Which obviously makes sense.

93 being so much more $$ these days does possibly introduce it going stale from sitting around a long time. I got gas at a station in Providence Forge west of me and it was obviously not right from the get go... My car was stuttering and running off from what it normally does... I put some Lucas oil octane boost in there and 5 gallons of much better gas in there. Car ran much better after that.
 
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You're good because the EVAP system will keep it from evaporating. Or, more specifically, the lighter volatiles.

However, if you put some sta-bil in now, it will prevent against future worries.

However, there are many, many people in your situation doing just fine.

My F150 gets driven ~400 miles a year, two tanks of gas.
 
Originally Posted by mclasser
Haven't been driving much lately but the Accord in particular has had the same tank of gas in it for nearly 8 wks.

Is that a problem? Does gas turn "stale"?

Go for a long-long ride somewhere.
Just remember how to get back.......

I've kept gas in it's red can inside the garage for up-to six months. I heard my timeline degrades pretty slowly and the staleness shows it's head in a lesser MPG reading.
 
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So i've left E10 in my chainsaw for > 6 months and it definitely doesn't keep the saw running; i dump it out and add fresh gas and no problems.

I believe I read somewhere that E10 should be used in a few months and is not a good storage fuel.
 
Originally Posted by ZeeOSix
LOL ... 8 weeks ... forget about it. I've fired up and ran vehicles with 1+ year old gas and there were no issues. Gasoline today is way more stable than it was 20+ years ago.

Not the E10 thats reqiired here. It goes bad quickly even with stabil added. My tractor sat a few months and it just would not start until i put fresh gas in it.
 
There is a big difference between a FI vehicle with a fuel pump pushing 50 psi (or much higher if DI), compared to a gravity feed OPE or a non FI car.

I've seen gas in a deployed service members car sit for 3 years and then start instantly.
 
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In a car with a relatively full tank it will not be a problem. The systems are all sealed now adays and the winter months are the easiest on stored fuel. Fuel stabilizers will not prevent E10 from absorbing moisture but the sealed system will, they will help with oxidation which is the reason to keep the tank as full as possible. I dont like it but my RV sits for months sometimes. I start it every couple weeks and take it for a drive once a month but the gas can be in the tank 8 mos or more. I do try and add 93 before it gets parked just incase it loses some octane.
 
I just ran a pressure washer that had 3 or a little longer old gasoline .The engine started and ran fine. I drained the res tof the gas out and ran 2 tank fulls in my lawn mower. No preservatives used.
 
Originally Posted by CT8
I just ran a pressure washer that had 3 or a little longer old gasoline .The engine started and ran fine. I drained the res tof the gas out and ran 2 tank fulls in my lawn mower. No preservatives used.



How old was that pressure washer ??

The one which was a pterodactyl swinging it's wings while you threw water up in the air so it would hit the house
lol.gif
 
I considered buying a Triumph TR6 that had sat for possibly 20 years under a tarp in an unheated garage. It was a nice looking car (even if bright green) except for the thin rust line on all the fender-body seams. We started it up and it wasn't long before fuel was pouring out from of the fuel pump onto the ground. It smelled awful. And the brakes didn't work any more either because there were leaks everywhere. He wanted a premium price. I passed on it.

So don't let a car sit for 20 years. But 8 weeks should be fine.
 
How does Stabil or the other fuel stabilizers work to keep gasoline from going stale?

If I'm not mistaken, "stale" gas is gas where the lighter more volatile compounds evaporate, leaving the heavier hydrocarbons, possibly forming gums or varnish if left far too long. You're still going to have those more volatile compounds regardless of what you add and they're still going to want to evaporate. Ethanol presents another issue being hygroscopic, so invites water into the gas... No fuel additive is going to change that.

So how does Stabil combat these problems? Looking at the back of a Stabil container, it contains "petroleum distillates." Gasoline itself, is mostly a petroleum distillate. As is kerosene, MMO, mineral spirits, toluene, heck just about any fuel additive is made up of petroleum distillates. Wonder what makes Stabil work its magic, I've often wondered if it's just "snake oil" with a feel-good, good reputation.
 
I just fired up my ATV today that's been sitting since the end of last October. Cranked over less than 2 seconds then vroom. I was however using 91 non-oxy fuel.
 
Interesting. I got some shell v-power from a busy gas station a few months ago and today when I pour it into my lawnmower I noticed the gas was already looking amber. I did put some sta-bil in it, maybe the jerry can have a vent leak somewhere?
 
Originally Posted by Chris142
Originally Posted by ZeeOSix
LOL ... 8 weeks ... forget about it. I've fired up and ran vehicles with 1+ year old gas and there were no issues. Gasoline today is way more stable than it was 20+ years ago.

Not the E10 thats reqiired here. It goes bad quickly even with stabil added. My tractor sat a few months and it just would not start until i put fresh gas in it.


We've had E10 here for 20+ years. I've never had any problems.
 
Used some 87 octane pump gas I bought in October to fire up my push lawn mower last week. That's about 6 months. Fired up rapidly on the first pull. I didn't expect it to be that fast.
 
Originally Posted by 69GTX
Used some 87 octane pump gas I bought in October to fire up my push lawn mower last week. That's about 6 months. Fired up rapidly on the first pull. I didn't expect it to be that fast.



Try to keep the carb empty when it sits long term. That ethanol draws up enough water to corrode the inside of it. Once you tear a few of these small carbs down it's pretty obvious what that alcohol does inside the passages when it sits a long time. My snowblower when I got it had the bowl corroded in the very bottom. One spot even pinholed right through. That's the ethanol's magic legacy .
Luckily even the peasants here in the People's Republic can find ethanol free and that's what my small stuff gets and I still drain those carbs when they sit. If there's no drain on the bowl toss on one of those tiny plastic shut offs is there's enough room.
 
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