What to do with stale petrol?

[Alan]

I bough a gallon can of lead-free petrol when there was all that kerfuffle about fuel prices a few years ago which has sat at the back of the garage ever since. During a clear out I unearthed it again and now I need to get rid of it (especially as we've got a diesel these days). I tried taking it to the council dump but - "we've got no facilities for handling liquids guv - do you have a lawnmower?" - yes I do but it's electric :-).

So the question is - will this old petrol be usable in a petrol lawnmower? If so, I can pas it on to a mate.

Alan

[Clive]

Pour it down the drain.

[David in Normandy]

But wait until you see someone walking along the pavement with a cigarette between his lips and watch closely as he tosses the stub down the drain :-)

[Andrew Gabriel]

Good idea.

[Al]

Yes.

I used loads of 'stale' petrol in my youth from rusty old Duckhams old cans the my dad had in his garage. Used on various 4-stroke motorbikes with no problems.

Al.

[Harry Bloomfield]

Alan wrote on 10/05/2009 :

They say it goes stale in just a few months, but I have never had a problem using old petrol stored for lawn mowers or in the bike which can stand throughout winter. I suppose you could always mix it with some fresh petrol if there are doubts.

[Dave Liquorice]

It'll be fine.

Pass it on to anyone with an engine that runs on petrol it'll be fine.

[Steve Walker]

For such a small amount, just chuck it in the petrol tank when it's three quarters full. AFAIK stale petrol is just petrol that has had some of the lighter molecules dissipate to atmosphere. There's nothing actually wrong with it, it just doesn't burn as well as fresh stuff.

SteveW

[Tim S]

Harry Bloomfield coughed up some electrons that declared:

I just broke out the petrol mower that's had a tank of petrol going idle for

6 months. Worked fine. Never understood this "going stale" business...

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Alan saying something like:

Of course. In a low-tuned engine like that, no worries. If in a higher state of tune you might want to add it to a nearly-full tank, but otherwise, ok.

[Mike Barnes]

A cigarette won't ignite it. :-(

[Dave Liquorice]

I wouldn't like to bet on it or is that a :-( of experience?

Flash point for petrol is -43C above that enough vapour is released to become a danger if enough heat is provided and air/vapour mix is right.

But baring having the right vapour mixture the spontaneous ignition temperature of petrol is somewhere bewteen 200 and 300C, a cigarette smoulders at about 400C. So even if the vapour doesn't go boom from the cig butt when that hits the petrol puddle it's quite likely to start a fire. And petrol burns rather too well.

[<me9]

Stick it in the diesel car next winter. It was common practice to add a gallon of petrol to a tankful to stop sludging in the winter in the 70s. Diesel is now better adjusted for winter use, but the odd half gallon of petrol to a tankful wouldn't harm. wouldn't harm.

[John Rumm]

Odd as it sounds, it would do no harm to chuck it into a nearly full tank of diesel. (HGV drivers often mix small/moderate quantities of petrol into diesel to prevent waxing in very cold weather).

[Frank Erskine]

On Sun, 10 May 2009 23:59:06 +0100 (BST), "Dave Liquorice" had this to say:

In a GPO depot in the 60s there was a petrol-pump attendant who used to look after an indoor petrol pump. He was a smoker and used to extinguish his ciggies by squirting them with petrol from his pump. He lived to retirement age...

[Harry Bloomfield]

Dave Liquorice brought next idea :

I could get it to ignite, I tried it several times. Take a very small quantity of petrol (thimble full) and a lit cigarrete on the end of a long stick. The fuel extinguishes the cigarette. I have not checked the temperatures, but could this be a similar principle to the fire walkers not suffering burns on the feet?

The ash on the burning coals insulating and the brief time protecting the walkers feet from the heat - ash on the cigarette preventing ignition?

[The Medway Handyman]

Entirely possible to stub out a ciggarette on your tongue without burning it. Never done it myself, being a chicken, but a non smoking mate of mine does it as a party piece.

[The Medway Handyman]

How does petrol go 'stale' then?

[<me9]

In the fuel crisis of the 70s I needed to do a long journey. In anticipation I stored a few gallons in a mixture of containers in my parent's external bog. I found a suitable source of fuel so I never used it. About a year later I rediscovered it, that stored in plastic containers had gone down about 20%, but stored in metal cans had not lost any. It all worked fine, but probably I diluted it with fresh.

[Bob Martin]

See the end of National Lampoon's Christmas Vacation for a demonstration.