Old gasoline 3

[rmw]

I had to get the generator out yesterday and get her ready for Hurricane Rita, in case she came as far north as I am.

At this writing, the storm is still on her way here, but we still have lights. Not everyone in the community does. I have heard several transformers blow their tops off earlier today.

That said, it had been some time since the generator last ran, and it had been left full of gas which had that 'old gas' smell. I had to drain it all out, clean the carburetor bowl, etc., and she fired off OK. (Honda generator-danged fine engine.)

What is 'old gas' and why does it smell that way when it is old? Can it be blended back with 'new gas' and burnt in (1) the generator (if I need to run it) or (2) one of my gasoline vehicles, all with cadillac convertors. (I wasn't sure I could spell catylitic.)?

rmw

 

[EHudson]

Gasoline components oxidize in time resulting in what is called 'sour gas'. It will have lost volutility making starting more difficult. It can be harmful to fuel system components with prolonged exposure.

Engines can and have run on sour gas. The biggest problem with old fuel can be water accumulation with attendant corrosion and plugging of small jets. You apparently do not have plugged jets since the engine runs.

Mixed with other gas in modest amounts it can work in a engine but why?

If it was the only fuel available in an emergency I'd use it after checking for water and maybe filtering it through a coffee filter if there are solids present in any amount.

Best of luck to you riding out the storm.

 

[rmw]

Why?

I was raised by folks that survived the great depression, and I was taught to waste nothing. And, at $3.00+ per gallon to replace it.....

Second, how would I dispose of it. I was also raised to just pour it into the sewer, but environmental awareness had put an end to that type of stuff. So disposing of it would be problematic. I am not sure putting it in an old gallon size oil can and putting it in the garbage would be an acceptable solution if I were the bulldozer operator at the land fill.

So, it still has some value. I have begun mixing it slowly into several vehicles. They will never know the difference.

rmw

And, PS, we came through the storm just fine. Thank you. I never had to use the generator, although many in my area did have to use theirs or do without power.

 

[GregLocock]

2 year old gas seems to work fine in my lawnmower (B&S) and my weed whacker (Ryobi 2 stroke)

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[swall]

I take my old gas as well as old 2-stroke mix and mix it in with diesel fuel (approx 5% max) and run it in my tractor.

 

[Compositepro]

Gasoline contains a significant percentage of alkenes which are hydrocarbons with double bonds. These alkenes are reactive and will react with oxygen and each other to form higher molecular weight compounds that will be seen as gums or varnish. This can cause parts in in the fuel system plug or get stuck. The main problem when the gas is left in place a long time. Blending with fresh fuel is usually okay. The problem with blending gas with diesel is the safety issue with flashpoint. A gas tank will not explode because the vapor in it is above the flammable limit. Diesel is below its flash point at room temp. A small amount of gasoline in diesel can place a vapor space in the explosive range.

 

[swall]

I seem to recall that GM told owners of its late 70's/early 80's diesel cars (the diesels converted from gas engines) they could use up to 20% unleaded gas in the diesel fuel in the winter to mitigate fuel jelling. Is this just heresay, or did they back off of this?

 

[rmw]

I think it is more than hearsay. They said something like that-just with a warning not to use leaded gas which could still be found in those days.

That said, based on GM's experience with diesels back in those days, I don't think I would use them as a reference for much of anything.

I still owe them a debt of thanks for introducing me to Fords. (It was transmissions too, not just the convert-a-engine.)

rmw

 

[diyrandman]

If in the case of gas storage for extended periods i.e. winter,use fuel stabilizer. When used creates a film on the top surface of the fuel greatly reducing evaporation and the oxygen reaction to which Compositepro referred.

 

[patdaly]

Swall, I dont know if GM ever told users to add Unleaded, but I did in a pinch when #1 was not available. 20 percent is entirely too high though, 1 gal per 16 ( about 6 percent ) always worked for me. I would only do this when the temps were expected to drop well below -10 for long periods, otherwise regular winterized diesel worked fine. If #1 was available, I ran roughly 25 percent.

rmw, funny you should say that, Furd is the reason I now drive exclusively GM products. I guess it is just the luck of the draw.

 

[kenre]

I have no idea on GMs ideas on mixing petrol (gasoline) with diesel, But i do know that SAME, Italian tractors have written in the manuals that up to 20% gas can be mixed with the diesel fuel below certain temperatures.

Ken