Life of Petrol?

Two things limit the shelf life of petrol

1. Evaporation of the light ends - this can be stopped completely by having it tightly sealed, and if this is the case this factor does not limit the life.
2. Bacterial attack. The time taken for this varies enormously, and depends on :- humidity/water contamination, temperature, agitation, and to a minor extent access to air. It can be completely prevented if the petrol and container are not infected, but although there are probably some around that aren't, it is probably safest to assume that it is infected. Best precautions you can take are to keep it absolutely dry, and add one of the antibacterial additives - or do what most of us do, and don't store it for more than a month or two. JD

Came by a Midget the other year that had been stored for 10 years with a full tank of 4 star. Midget would only do about 45 mph, and that reluctantly, on it. Drained it out, put it in the Series 1 and it loved it! Ran like a dream.

However I believe unleaded goes off quicker, although my lawnmower doesn't seem bothered by 9 month old UL.

Gordon.

Good job really!

Nige

Yeah, I had a car with 10 year old petrol. It wouldnt start until we drained it and put in fresh. After we drained it we tipped it on a fire and it put the fire out - so it obviously wasnt petrol anymore!

I did successfully run a Seagull outboard on some petrol from a can that had been in a garage since the War!!

Jeff

Can't see why petrol should have a shelf life when it is distilled from crude which is millions of years old and simply a mix of diffferent fractions one of which is oil ?

It's still an organic chemical which can react with others to produce new substances, which may be less flammable than the original.

A litre of petrol, as part of an oil well and fully mixed with a load of other oil fractions, is pretty well isolated from any external reactants. A litre on its own in a mucky tin with a lid that may or may not be airtight is a rather different beast.

You'd be amazed what low-compression petrol engines will run on.

Alex

I spoke to the chap I got the new 5.2L TVR V8 engine from the other day. He was stunned that I hadn't put it in Grumble. He was even more stunned when I told him I'd filled all the pots with engine oil while it was standing to prevent corrosion. He firmly believes it will never run properly now - as it's had oil in the cylinders!

Yeah, and that...

Anyone remember the site with the quality data on LPG which demonstrated the UK has the foulest on the planet?

Don't mention the war. I did once, but I think I got away with it...

(I can do the walk...)

Yeah, or any other catalytic intervention. My smile was caused by the jerry can being the most rancied and mucky amongst my (growing) collection. I put it down to the new, 15p rubber seal miself mind.

Buggrit, that's too sensible...

I totally agree, however I was refering simply to the idea of a shelf life for petrol, not that it would be kept in awkward conditions. In a good container with no contaminents I'll bet the substance would last indefinately ( apart from evaporation or diffusion ).

A litre on its own in a mucky tin with a lid that may or

What's wrong with that? I've got a 2.25 petrol with the head off sitting outside. The bores are packed with grease, ditto the holes 4 the cam followers, top of the block also covered, and a lid over.

Alex

LOL. My race car engine spends every off season sitting with oil filled bores and still made it's full complement of horsepower (all 490 of them) the last time it was near the dyno.

On or around Tue, 15 Mar 2005 22:45:13 +0000, Mother enlightened us thusly:

so am I, to be honest :-)

Ah Seagulls..... they'll run on anything that's not 100% water and even that's worth a try....

Managed to get mine to run backwards once.

TonyB