Does engine oil have a “Best before date”

[jenevers]

?

[Movin' on]

Its generally "best before" its used - sorry could resist, it must be lockdown fever?

Edited May 6, 2020 by Halsey

[frangar]

Oil companies generally say 12 months in a sealed container but I think that’s because it’s how long they keep test samples should an issue arise. I’m not sure personally I’d risk it if it was much over 2 years old in a sealed container....I was given some that was about 20 Plus years old that I emptied into an oil recycling...that was very gloopy! 

[Movin' on]

What causes it to degrade - temperature?? I use stuff from one season to another and have never even given this a thought............

[Tony Brooks]

13 minutes ago, Halsey said:

What causes it to degrade - temperature?? I use stuff from one season to another and have never even given this a thought............

We know it oxidises i n use and contains anti-oxide additives so if there is a ready supply of oxygen then I suppose the anti-rodents may become depleted a din the long term the oil may oxidise but is there a ready supply of oxygen in the can? I suspect in a steel can the only way in would be via the cardboard cap seal but with plastic I am not so sure how permeable it would be.

 

I have just poured some 5 year old or more oil into my lawn mower and it flowed and looked fine to me.

[frangar]

I also wonder if synthetic or semi synthetic has a different shelf life than a “straight” mineral oil? 

[john6767]

7 minutes ago, Tony Brooks said:

We know it oxidises i n use and contains anti-oxide additives so if there is a ready supply of oxygen then I suppose the anti-rodents may become depleted a din the long term the oil may oxidise but is there a ready supply of oxygen in the can? I suspect in a steel can the only way in would be via the cardboard cap seal but with plastic I am not so sure how permeable it would be.

 

I have just poured some 5 year old or more oil into my lawn mower and it flowed and looked fine to me.

You changed the oil in a lawn mower?  That is very fastidious, had a mower for over 30 year never changed the oil, not even sure it has ever been topped up either.

[Phoenix_V]

 

21 minutes ago, john6767 said:

You changed the oil in a lawn mower?  That is very fastidious, had a mower for over 30 year never changed the oil, not even sure it has ever been topped up either.

Was it electric

[Tony Brooks]

1 hour ago, john6767 said:

You changed the oil in a lawn mower?  That is very fastidious, had a mower for over 30 year never changed the oil, not even sure it has ever been topped up either.

Who said anything about changed?  Its so old its turned into an almost total loss system so its just a top up a couple of times a year.

Edited May 6, 2020 by Tony Brooks

[LadyG]

1 hour ago, Tony Brooks said:

We know it oxidises i n use and contains anti-oxide additives so if there is a ready supply of oxygen then I suppose the anti-rodents may become depleted a din the long term the oil may oxidise but is there a ready supply of oxygen in the can? I suspect in a steel can the only way in would be via the cardboard cap seal but with plastic I am not so sure how permeable it would be.

 

I have just poured some 5 year old or more oil into my lawn mower and it flowed and looked fine to me.

I wonder if it affects you typing skills Tony, or was it the rodent bite? ?

to change the oil, most modern lawnmowers just need to be tipped on their side, and it pours out the dipstick, pays off , a good Honda will last for years if looked after.

Edited May 6, 2020 by LadyG

[Tony Brooks]

1 minute ago, LadyG said:

I wonder if it affects you typing skills Tony, or was it the rodent bite?

Thanks - edited.

[john6767]

1 hour ago, Phoenix_V said:

 

Was it electric

?

[Machpoint005]

7 hours ago, frangar said:

I also wonder if synthetic or semi synthetic has a different shelf life than a “straight” mineral oil? 

 

Straight mineral oil has been underground for millions of years.

 

Just sayin'!

 

 

In all seriousness though, in answer to the OP's query, I wouldn't worry at all. The engine in a narrowboat is hardly a highly stressed environment given that it barely does 1200- 1400 rev/min most of the time.  

 

 

[Momac]

I don't think twice about keeping leftover engine or gearbox oil a year or two before using it.

I expect decade would be okay in a sealed container.

 

[Bobbybass]

In the 'classic car' market....unopened tins of original oil fetch good prices.

 

They are sought out and used...many being 30-50 years or more.

[frangar]

41 minutes ago, Bobbybass said:

In the 'classic car' market....unopened tins of original oil fetch good prices.

 

They are sought out and used...many being 30-50 years or more.

Mainly for the tin rather than the oil I hope! 

[Bobbybass]

I guess if it's been in the ground for 50 million years....it's bound to expire some day.. 

[cuthound]

No, engine oil doesnt degrade quickly if it is kept at rrasonable temperatures and in a sealed container.

 

When i worked for BT i was part of a team charged with reducing the maintenance commitment without impacting on equipment longevity or mean time between failures.

 

By taking oil samples from the standby generators and analysing the results we increased the oil change periodicity from 1 to 6 years, and stored oil (BT generators have a lube oil makeup tank to allow up to 10 days continuous running) was also unaffected.

 

However it is important to note that standby generators use crankcase heaters to keep the coolant up to operating temperature (to allow full load starts from cold without excessive wear), so the oil never had any condensation in it.