News, Can gas really go bad? (auto, motorcycles, plugs, fuel)

[John1960]

Does gasoline really go "bad" if you leave it unused for a period of time? Some people are convinced this is just another urban legend, and that people who worry about "old gas" and spend money on fuel stabilizer are wasting psychic energy as well as cash.

Can gas really go bad? - CNN.com

[cdelena]

Yes, most that have left yard equipment for a long period or failed to get a car out of storage have seen some starting problem and if you disassemble parts you may see gummed up parts. I use stablilizer in gas for yard equipment and have tried to use a tank of auto gas within three months or so.

[NHDave]

It will go bad eventually, but it's been my expirience that it lasts alot longer then they'd have you believe. I've left my lawn equipment all winter with no stabilizer and had no problems starting in the spring.

[shipm8]

I purchased a plastic 5 gal jug of gas for my lawnmower 3 years ago this May, still some remaining that I will be using this year, will let ya'll know if it's still good!

[ThAdam]

i have heard that is goes bad, but i think the real problem comes when the motor sits and the gas in the carb or lines dries out and leaves something like shellac in the parts.

i have drained the gas from an old car after it sat for a few years and then used that gas in a lawn mower without an problems.

[StealthRabbit]

the newer gas (last 10 yrs) has lots of additives that evaporate FAST. It is murder on my older motorcycles which must be drained if sitting for over a couple days.

The gas reacts with carb parts and softens lines and seals, and when it dries out it plugs little passage ways in carburetors.

Stabilizer is a plus in yard equip.

If possible turn off the fuel and run it till carb is dry. Many of us do that on our gensets in Motorhomes.

I do have a 1953 Farmall tractor that I use a couple times / year, and it seems to do fine. It has fiber / felt components in carb, not rubber, and no rubber fuel lines, and it is not too picky what it drinks. The majority of my engines (31 OF 46 TOTAL) are diesel (Which the new stuff is not good either, but at least it doesn't evaporate !!)


Mainly, VW Rabbits and a few Passats and Jettas, (all 50 mpg) and dozers, tractors, dumptrucks...not 50 mpg..., but one dozer is really 'thrifty' ~ 1 gal / hr

[studedude]

Originally Posted by John1960

Does gasoline really go "bad" if you leave it unused for a period of time? Some people are convinced this is just another urban legend, and that people who worry about "old gas" and spend money on fuel stabilizer are wasting psychic energy as well as cash.

Can gas really go bad? - CNN.com

A lot of lawn mower shops are gearing up to make a lot of money cleaning an urban legend out of carburetors on mowers left last years gas in their tank over the winter. I have made a living doing just that.

[Magnulus]

Not an urban legend. Ask any motoryclists with more than 1 bike. I put Sta-Bil in any bike that gets infrequent riding (plus a Battery Tender).

With a two cycle engine on a weed whacker or leaf blower you won't notice it as much because the combustion is inherently dirty, but on a 4-cycle engine you will notice bad gas more. Rough running, more deposits over everything, etc.

[cb at sea]

Yep--gas can go "Bad"!

[recycled]

I don't know how much the additives evaporate like one other comment said. My thought is that if there is a partial tank of gas in a car or other vehicle, the air inside the tank leaves space for condensation to occur as temperatures change. This is the most common way that you get water mixed in with gas. If you leave that part empty gas tank sitting for a long time, more and more condensation develops, leaving more water in the tank, the gas ends up with too much water in it to properly ignite. Hence, "bad gas" largely from water.

On the other hand, if the tank were as full as possible before leaving the vehicle sit for a period of time, it is less likely that you will get much water in the gas because there's little or no air space left in the tank for condensation to occur. When I lived in places where the winter climate was very cold, I would keep my tank topped off frequently to avoid condensation inside and having the gas lines freeze from water in the gas. It worked quite well.