Diesel fuel storage question?

Thinking about getting a 500 gallon diesel tank for the tractors and a car. Just curious, how long can diesel fuel be stored?

I know with gasoline it SHOULD be stabilized if storage is going to extend past a couple months. Is there some sort additive that should be added to diesel if it is going to be stored for up to 6 months?

What happens if you mix in "fresh" diesel with "old" diesel (refilling the tank when it is only 1/2 empty?).

Thoughts, ideas, suggestions?

One thing for sure, you need a biocide. Little critters love diesel. When you use the fuel, yopu need to make sure that you are removing any condensation. Diesels do not tolerate water well. Probably dumb of me to say thast you probably already know.

Beyond that, I really do not know. I once had a buried 1500 gal #2 tank for oil heat. The oil was there for three years before it was used. no problems. An engine wooould be another story.

Hope this helps.

Underground storage is better for any fuel because of slow temperature change thru the seasons. I agree the biocide would be a good idea. As said, be sure to install a fuel filter/ water separator on the tank and open the water drain on it at least once a month, more often during spring and fall.
Mike

Actually it does help. I totally forgot about the need for biocide. I knew that diesel could grow little critters, but forgot to take that into account. As for the condensation, yup very aware of that and the problems it can cause.

Still does diesel lose its ability to burn over time in storage?

Not near as much as Gasoline. I have a 300 gallon skid tank and the only thing I do is dump 150 gallons of kerosene in it during winter. I have fired up diesels that sat for over 5 years on the fuel they were parked with. I have heated with 15 year old #2 and it burned fine. Set the pump stem for 1" off the bottom of the tank and pitch the tank toward the drain and you will be fine. I am a cheap SOB and used to get all sorts of old and contaminated fuel and burned all of it after letting the water and sludge settle and separate. My boss gave it to me so he did not have to pay to recycle it.

I'd suggest adding some PSA to the storage tank. white bottle Power Service Additive: which has a preservative, some mild cetane boosting properties, and most important - gelling inhibitors, in it.
There are other brands/similar products out there, but this is the one I got the most consistent positive reviews from other tractor owners on a couple of different tractor forums. (and they have specific versions for "old" diesel, ULSD fuel, and biodiesel)
This same company also makes a "recovery" version that will dissolve the wax clogging your filter from gelled fuel, in case you have a cold snap before adding it to the tank.

I suppose that if one thinks about it, Oil was around in the ground for a long time before we pumped it out. LOL

Well, you got it all ... biocide, anti-gelling agent and water absorber/stabilizer and it will last for many years. In my experience with farm fuel in tractors, at least three. Worked just fine.

The only thing is that you will be buying clear diesel and not the dyed stuff if you are going to use it for a car so you will be paying tax on your tractor fuel, assuming you have or can get an ag exemption. I know that in Texas that would be an extra $225 on a 500 gallon fill up. Not much for a man in your position Bob but it's still another 10 boxes of ammo.

i work for a fuel company here in bush alaska and we are iced in 8 months out of the year we buy our fuel in milion gallon batches to last through the year over 1 year periods the fuel comes out of our above ground tanks clear and clean. no problem on the smaller tanks you will find the algee growth speed up rapidly with hot and cold cycles on the tank and that will also cause condensation problems i some times pull black colored heating oil from my tank and run it through my 6.2 diesel with no problems but i change filters regulary just get a good filter system and add power service to your fuel especialy important because you guys down there are using ulsd and lubercation is for your moving parts in injection system is almost non existant.