regarding petrol going off in storage.

[to v or not to v]

i help a chap with an allotment. in the spring of 2019 i bought 5 litres of Shell regular unleaded for a strimmer i use. kept in a plastic fuel container and mixed it with Rockoil 2 stroke to the required amount. 1 part in 20 i think? as soon as i purchased it.
last year it didnt get used at all due to covid. this week i got the strimmer out, filled it with the 2+ year old fuel and it fired up straight away with no problems.
would the 2t oil make a difference, or is the short shelf life of petrol greatly exaggerated?
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current bike Yamaha Thunderace.
Moto Guzzi V7.

[xX-Alex-Xx]

In a can it probably wouldn't be too bad. It's when it's not moving in fine holes like fuel injectors that it'll evaporate off and leave a varnish behind which will block or partially block the hole.
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DILLIGAF

[Copycat73]

Says more about the strimmer motor than the fuel .. try puttin it in a bike and see Wot happens..
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Whatever I post I have no citation and no intention of providing one..
caveat emptor

[MarJay]

It's not as simple as that. Your question implies a binary state that does not exist.

Petrol is not one homologous substance. It's not pure Octane or whatever. Petrol is a blend of hydrocarbons from hexane, to octane to all sorts of chains of C and H together, as well as some ethanol these days (up tp 5% but soon to be up to 10% Yikes). The reason it goes 'off' is because some of the elements of that blend are more volatile than others. By volatile, I mean that in the chemistry sense, not in the general use sense. It doesn't mean it might throw the crockery across the room and run away with the postman, what it means is that it naturally vapourises at room temperature. There is a % probability of it being vapour at room temperature, and different volatility levels mean a different percentage and all that chemistry malarkey.

So, what that means is that some of the blend vapourises, leaving behind the more stable parts. In a motorcycle, car or other vehicle you cannot have buildup of vapour due to safety issues related to pressure and flammability or explosiveness. Hence why there are breather pipes on fuel tanks. In that case, if fuel is left in a car or bike, the volatile parts of the fuel will vapourise and leave the tank via the breather. The downside of that of course is the volatile parts are the parts that burn easily, meaning the sludge you're left with after a long time is not very good as a fuel.

In a Jerry can or Green plastic fuel can, the vapour can't escape. The changes in temperature etc would mean the vapour could return back to a liquid state, and in reality this process is basically happening all the time. So, if you keep the fuel in a sealed can, and make sure it's agitated enough when you go to use it it should be OK.

This does not preserve the fuel indefinitely, but it will increase the shelf life by a LOT. So, your premise that the short shelf life of fuel is exaggerated is in fact incorrect.

Then there's the other additives such as stabilisers, detergents, ethanol etc... that's a whole 'nother can of worms and that's usually the stuff that leaves the 'glue' behind when the fuel has completely vapourised.
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[stinkwheel]

Also, being in a sealed can, it can't absorb moisture from the atmosphere.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[chickenstrip]

[jeffyjeff]

To Marjay's point, the lighter constituents in the fuel that vapourise most readily are the same ones that promote easy starting and smooth running in cold temperature. The lightest ones are propane and butane, to my recollection. You would likely notice their absence more readily if you were trying to start your motor in sub zero temperatures.
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History shows again and again how nature points out the folly of men - BOC

[doggone]

The ethanol absorbs water from the air and encourages fungal growths.
That will be minimised in a full container with good seal and it would help if temperature was on the low side.

[Blah blah]

I bought a pickup that had been stored in a barn for 8 years. I dropped the oil, flushed the coolant, new filters, cam belt and plugs then turned it over and to my surprise that started with the old fuel.

The neighbours were less impressed when the exhaust turned into a pile of rust under it...

[to v or not to v]

[MCN]

Breather serves the equally important purpose of allowing an atmosphere into a tank, otherwise the tanks contents would not pour out due to equilibrium.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[Blah blah]

[MarJay]

[MCN]

[to v or not to v]

[MCN]

[iooi]

[A100man]

Yeah, can't say I've had a lot of trouble with 'stale' fuel to date in spite of the doom mongers.

Moving to 10% booze though might prove a different story. Makes me wonder - where does it all come from? In Brazil it's brewed up from sugar cane isn't it?
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Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[Robby]

[Kawasaki Jimbo]

[Kawasaki Jimbo]

Regarding fuel “going off”, it might absorb water or lose some of the the most volatile components but it’ll still be flammable. I’ve never had a problem.

[Robby]

Food waste could make sense, but would likely be pretty poor in terms of the carbon balance. You would need a plant that can take all manner of inputs, which is going to be less efficient. You also have to get all the waste material there, which will means lots of road transport trips.

Algae could work, but really it's too late. Petrol cars are here and going to become the majority on the road quickly. If algae made sense, it would be here by now - I first saw stories saying it was going to be the next big thing 20 years ago, which is plenty of time to go from concept to commercial reality.

I can see biofuels having niche applications* when most of the vehicles are electric, and it would be less bad then if the entire biofuel manufacturing and supply chain ran on renewable electricity. Right now they're just greenwash.

*not aviation. I don't see that getting away from fossil fuel for decades. Might start happening when Florida is mostly underwater.

[Kawasaki Jimbo]

[Robby]

Aviation is a big driver for biofuels from people that want to sell biofuels. It's a big thing for the airline industry to talk about wanting to do (lots of hand wringing), but not being able to do because safety. I was intimately involved in this a few years back.

Early tests were carried out about 10-15 years ago using biofuel in airliners. Never got any further. Turns out that people who care about emissions from aviation just try to avoid flying altogether, and governments around the world can't even get a decent amount of tax on aviation fuel, let alone force airlines to use biofuel.

The main issue is safety. Airlines will only trust biofuel after millions of miles flown on it and thousands of inspections, particularly looking for any evidence of mould or icing in the fuel system. No-one wants to pay for this, and by the time it gets anywhere near reality battery tech should be giving us electric airliners, at least for short haul. So a risky investment with a lot of push back.

Still, I'm hoping that airlines may get a bit more co-operative post covid, assuming passengers numbers stay below their pre-pandemic levels and a few companies go bust. Tends to focus the minds of the remaining ones to stop pissing off governments, and treat your passengers a lot better.

[MCN]