How long does stored diesel last?

[Steve Bean]

What is often called "algae" in diesel fuel is actually fungus that lives at the interface of the fuel and water at the bottom of the tank. Another myth is that sulfur provides lubricity. Actually, the process of removing the sulfur degrades lubricity.

[newhaul]

The best adative to increase both cetane value and lubricity best is biodiesel. I will post the link to the blind study when I find it later today.
Found it faster than I expected
http://www.dieselplace.com/forum/76-...y-results.html

[a64pilot]

Originally Posted by newhaul

The best adative to increase both cetane value and lubricity best is biodiesel. I will post the link to the blind study when I find it later today.
Found it faster than I expected
Lubricity Additive Study Results - Diesel Place : Chevrolet and GMC Diesel Truck Forums

I run 20% Bio when I can find it in my truck for that reason, however the fuel in my truck gets used pretty frequently, I do think there are valid concerns with Bio and storage, one reason is there are several forms of Bio-Diesel and you don't know what the component is, often it's Soy based, but not always, it can even be animal based, but that is I believe very un-common.
I was participating in a study to certify S-10 Diesel to be burned in aircraft engines in Brazil, and the biggest issue was that there were no real standards for the bio component.

[newhaul]

I can see your point I do know that here in Washington state the bio is corn based. We have the second largest production plant in north america second to Texas. So it seems that a 10% bio diesel and a good biocide would be the best combination for those worried about growth in their tanks that's what I have a water separator with sediment bowl before my filters for.

[Paul Elliott]

We have scientific evidence that diesel can be stored for at least 100 million years. At least that's how old it is when we suck it out of the ground. I suppose the refinement process might be a factor as well...

[a64pilot]

Funny thing is the S-10 project died in Brazil, as Jet-A is cheaper now.
Adding Ethanol to gasoline when gas is less than $4 a gl, makes the gas cost more, right now ETH costs WAY more than straight gasoline.
Same I'm sure for Diesel, I'm sure the Petro Diesel is much cheaper per gl than the Bio, but I don't know by how much.

[oceanbug]

Stored Diesel in a stainless tank for 8 years. Tank was not vented. Taken a sample into a glass container and it looked clear. Used all 200 liters of it without problem.

[Exile]

Fwiw, I looked into the issue of biodiesel a couple of years ago because I had to replace a leaky aluminum tank with a custom-built fiberglass one, and had to be sure that a compatible interior coating was used. What I uncovered was that up to 5% of bio can be added to diesel in the U.S. without the govt. requiring any notification to the consumer on the pumps. Any amount beyond 5% must be posted, however. Because suppliers try and use common pipelines for distribution, it is reasonable to assume that there may be up to 5% bio at marine fuel docks as well, at least in the U.S.

I'm told that bio supposedly does add lubricity, and would not affect my new tank's fiberglass coating with that low of a concentration (according to the coating mfg.). In higher concentrations it could negatively affect hoses, injectors, and other sensitive engine components. And since most if not all of it is alcohol based (soy/corn?), there's potentially the same issue of water separation/corrosion that afflicts ethanol in gasoline.

Good to hear that diesel stored in our sailboat tanks has a long shelf life, since it can take some of us awhile to burn it. I routinely polish it, add biocide, and occasionally cetane boost if it has otherwise not been refreshed in awhile.

[Exile]

Originally Posted by oceanbug

Stored Diesel in a stainless tank for 8 years. Tank was not vented. Taken a sample into a glass container and it looked clear. Used all 200 liters of it without problem.

I was always concerned about storing diesel with no venting. I know it's much more stable than gasoline in that respect, and guess your example proves it can be safely done. No venting would probably go a long way towards preventing condensation/water ingress in our boat fuel tanks during prolonged periods of non-use. Just gotta remember to open up the vents when it's time to get underway again!

[reed1v]

For those folks who are long distant voyagers and plan on storing lots of diesel onboard, you can attach a polishing rig for the tanks so your fuel is always being cleaned of contaminants. Works well. We also had three filters on our fuel line. Clean fuel keeps a diesel very happy. And do not forget the Baja Filter system when loading up diesel from some third world port.

[elandra65]

FWIW,

I had an interesting experience with older diesel. I filled up in Panama before a Pacific crossing to Australia. I then put the boat on the hard for about a year before I ended up overhauling the engine, rings, bearings etc etc. Another story! As it was a Volvo MD22 which is a little complex with regard valve timing I was very concerned about getting it right. Anyway when time came to start the newly overhauled engine it refused to start at all. Of course we checked all the normal things such as bleeding the system etc and it all seemed OK. Nothing seemed to work and I was greatly concerned. I ended up asking a very helpful local diesel mechanic to have a look. He cracked the injectors to check fuel flow and commented that the fuel smelt a bit odd. He then brought a container of his fuel and we tried it with that. After a bit of cranking to push the old fuel through it started straight away which was a huge relief. I don't know what was wrong with the fuel as it looked OK but it did smell different. It was at that time about 2 years old but I had used fuel preserver. I believe a lot of fuel available over there comes from Venezuela illegally as it is very cheap so maybe that has something to do with it. I did buy it from "Flamenco Marina" which is upmarket. So in answer to the original question. It depends!

regards

Andrew

[newhaul]

Originally Posted by Exile

I'm told that bio supposedly does add lubricity, and would not affect my new tank's fiberglass coating with that low of a concentration (according to the coating mfg.). In higher concentrations it could negatively affect hoses, injectors, and other sensitive engine components. And since most if not all of it is alcohol based (soy/corn?), there's potentially the same issue of water separation/corrosion that afflicts ethanol in gasoline.

Good to hear that diesel stored in our sailboat tanks has a long shelf life, since it can take some of us awhile to burn it. I routinely polish it, add biocide, and occasionally cetane boost if it has otherwise not been refreshed in awhile.

Fwiw biodiesel is made with soybean oil or corn oil or any other veggie oil it has nothing to do with alcohol and I posted a link to a blind study that showed bio diesel is a very good lubircity additive.

[moseriw]

Please keep in mind:

Plant oil: Pressed out of oilseeds - cold or warm pressed -
usually No common rail diesels
Biodiesel: cracked (refined chemically) product of pants or old plantoil or old veggie fat. - Before you use it check if the gaskets can handle it
"common diesel": Due to pollution control they delight us with up to 10% of biologic ingredients that cause black death.

And these are the facts. I wish it would not be like it is.

[reed1v]

Originally Posted by elandra65

FWIW,

I had an interesting experience with older diesel. I filled up in Panama before a Pacific crossing to Australia. I then put the boat on the hard for about a year before I ended up overhauling the engine, rings, bearings etc etc. Another story! As it was a Volvo MD22 which is a little complex with regard valve timing I was very concerned about getting it right. Anyway when time came to start the newly overhauled engine it refused to start at all. Of course we checked all the normal things such as bleeding the system etc and it all seemed OK. Nothing seemed to work and I was greatly concerned. I ended up asking a very helpful local diesel mechanic to have a look. He cracked the injectors to check fuel flow and commented that the fuel smelt a bit odd. He then brought a container of his fuel and we tried it with that. After a bit of cranking to push the old fuel through it started straight away which was a huge relief. I don't know what was wrong with the fuel as it looked OK but it did smell different. It was at that time about 2 years old but I had used fuel preserver. I believe a lot of fuel available over there comes from Venezuela illegally as it is very cheap so maybe that has something to do with it. I did buy it from "Flamenco Marina" which is upmarket. So in answer to the original question. It depends!

regards

Andrew

We had a similar experience in Jakarta. Found out the sulfur content was way high. Poorly refined diesel. Not uncommon.

[HappyMdRSailor]

Originally Posted by CSY Man

Coal.
You can buy coal from the Titanic on eBay..

Oh man... Do you think I could buy Titanic coal futures???? I may be looking at diamonds some day!

I saw the other day they were auctioning a "biscuit" from the boat...

Originally Posted by SWFLman

I'm restoring a boat that has been on the hard for at least the last 15 years. Pulled the diesel tank inspection plate the other day and discovered the tank was completely full. I'm pumping it out in drums in a couple of weeks to inspect the tank...... but not sure what I'm going to with in all.......

BURN IT!
(er... in yer enjin)

Originally Posted by ontherocks83

Is there a good (read easy) way to test diesel? i.e. through a chemistry kit ( kind of like the ones you buy at home depot to test water for lead or kitchens for meth) Now my interest is up and I would totally put a vented tank outside with diesel and a sealed one and test every 6 months for a few years to see the results.

Dude... You're headed right down the amateur meth lab path with all your talk of test kits and tanks n stuff...

Originally Posted by Emouchet

Every year, when my diesel tank is getting low, before I fuel up again, I empty first my spare plastic drum into the main tank.
This allows me to 'refresh' diesel in the plastic drum every year, and burn the one year old.

I try and practice this too... But with far less "regularity"