How long does it take for Diesel to spoil?

[Jettagli16v]

Just thought about this,
and I did some looking on Google,
but I could not find any (trustworthy) answers.

How long does it take diesel to spoil?
(as my car has been sitting for 4 months or so, with half a tank or more)
And  is there anything to add now that would save it, if it is no good?
I was just going to top off the tank, and add a bottle of Diesel Purge.

Thanks,
-Brad

[rabbitman]

I don't think diesel goes bad.

[rabbitman]

IIRC it lives in the water and eats the diesel as food...

 

 

[Vincent Waldon]

Firms that maintain diesel generators for public buildings etc will generally insist on using up the diesel in any given tank within 6 months, or they pump it out.

Back in the day when I worked at a large university hospital we actually ran the hospital on the backup generators every day for several hours... partly to test them, partly to use up the diesel, and partly because at the time it was actually cheaper for the hospital to generate its own power than buy it from the City utility during peak.

On a regular basis when we started them up someone would see the black smoke from the stacks and phone the government to complain that we were "burning body parts again".

[Jettagli16v]

Cool,
so I have no worries if I had an otherwise good tank of fuel
which has sat since March...

Thanks!
-Brad

[catlin_cava]

I seen leave diesel a year in the car and the thing started and works ok...Smoked alot thou

On a regular basis when we started them up someone would see the black smoke from the stacks and phone the government to complain that we were "burning body parts again".

Thats when you tell them its fuel efficient and saves on operating costs 

[burn_your_money]

The diesel in my truck was 3 years old and it ran no problem. It only had like 1/8th of a tank as well

[subsonic]

Diesel / #2 fuel oil gets cruddy the longer it sits, just like gas.  From what I have read, it seems like the 4 month mark is when it it no longer "fresh".  I just had 550gals delivered to the house a week or so ago.  That will last me about 11 months.  I added PRI-D to both tanks to keep it fresh and avoid sludge buildup.

[madrogers]

I bought a rabbit that sat for 4 years on 3/4 of a tank. it started up on it and ran good  so i just topped it up and that was 2 years ago.it did not seem to damage anything.

[ObscuredByClouds]

If there is moisture in the tank, then algae can grow.  IIRC it lives in the water and eats the diesel as food...

 

so it's algae living with no light source for photosynthesis?

[ObscuredByClouds]

Awesome. I've seen that before- why diesel and not gas?

[lovinthedeez]

The diesel in my truck was 3 years old and it ran no problem. It only had like 1/8th of a tank as well

when i rescued my rabbit, it had sat about the same time with the same amount of fuel in it.  started right up.     It did smoke like the dickens though for awhile. 

[jtanguay]

i've heard that diesel can break down over time.  but i think its like 20 years or so. i've said it before but there was a gold company that flew in a million litres of diesel fuel and all the equipment into some remote area up in northern Ontario back in the 80's, then walked away from it all when the price of gold dropped... now the government is getting worried about what might happen if that stuff leaks out!     i'd say gimme some of it, but i'd probably have to fly in  and its probably all bad anyways...

[bigblockchev]

We "polish"  or filter down to 1 micron , the fuel in our generator and boiler tanks on a 5 year rotation to remove the algae. The fuel will break down itself but that takes a really long time to happen like 10-20 yrs. It takes us anywhere from 5-8 yrs to burn through the fuel in a given tank completely. I wouldn't worry about anything less than a couple of years and even then I would just top it off and run it.  Even gas is good for a couple of years if it is in a reasonably well sealed container. If left out in the sun to evaporate diesel will lose the thinner fractions in a few months. Cheers Dan