How long does fuel last in a container?

[~Slideways~]

I did google it and got wildly varying answers. I have about 50L of BP 98 which is about 8 months old, was drained from a tank and put in fuel containers.

Some google results says its too old, others say it will last years.

I also have some which is probably about 6 years old in an old Honda dirt bike. Will just drain that and use for cleaning.

 

Does anyone have any knowledge of fuel in NZ, does it have any additives for shelf life?

 

 

[Transom]

No preservatives in pump fuel that I know of they prob count on turnover to keep it fresh - someone here must have worked at mars den point refinery they may know 

I have quite a bit stored for generator use in the apocalypse and I add a fuel stabiliser to it but still try to cycle it thru and replace every year or so ( bottle of fuel stab came with the gen can dig out details if ya want ) 

[GuyWithAviators]

Not sure on the specific time, depends on the ethanol content. 
This is a good additive if you are storing fuel: https://www.supercheapauto.co.nz/p/crc-fuel-stabiliser-350ml/395871.html

You can smell when fuel gets old, kind of varnish-y. I have a few motorbikes with old fuel in the tanks, I tend to put this in my modern car and it doesn’t care. But for small motorcycles they’re a little more fussy, still runs though. 

[gibbon]

I dont think you can really say for sure, even the "fresh" gas you got yesterday might have sat in the servo tank for months, and some storage tank for months before that 

[tortron]

"preppers" seem to rotate their fuel stores every season.

 

Low comp engine like a sidevalve will run on just about anything. Your modern cat car probs Gona want something less than a year

[Bling]

Depends what it's going in surely? A highly strung car that needs 98, noooope. A normal car probably won't care. My projects all run on old fuel due to low mileage, I do splash out and put 95 in them when filling though as it will be a long time between drinks.

 

[~Slideways~]

Well the stuff in the old Honda dirt bike smells pretty varnishy, I better not put the 8 month old fuel in the 200sx to get it started with new fuel system. I just need to empty out at least one 20L container so I can go get some new 98, maybe I'll just mix it into the wifes modern car.

[kiwi808]

You can buy fuel stabiliser which you can use in the 8 month old fuel. 

[ajg193]

Three possible ways for fuel to go bad from what I can imagine:

1. Evaporation of volatile compounds
2. Oxidation of compounds
3. Internal reaction between fuel compounds and possibly containers

For evaporation and oxidation I'd say these are pretty minimal in a sealed container. You will get some of the more volatile compounds permeating through the container over time if it is plastic so it could go bad like that.

Internal reactions? Not a clue how much these occur. Surely there is someone on here who works in the industry and knows the answer.

NPD says its 100+ Octane fuel has a shelf life of 6 months minimum if that's of any help.

/If it's in a sealed steel container and the container is pretty much full then it will probably last a long time, especially if kept at reasonably low temperatures. If you've got 500 mL in a 5 L engine oil bottle it probably won't be good for quite as long.

@Bling's advice seems sound.