4 year old diesel

[Charlie]

I just looked at my records and the last time I filled my diesel tanks was approaching 4 years ago. Two 35 gal tanks and down to 7 gallons. At the same time I put 10 gallons of diesel in 2 jeri cans which have lived in a cool lazaret in SF Bay. I am tempted to mix five gallons in each tank with 30 gallons of new diesel. But since it took 4 years to use up a full load of fuel I am hesitant to fill both tanks.

Any thoughts?

Also how do you dispose of diesel in the Grating State of Kalifornia?

[Minggat]

Originally Posted by Charlie

Any thoughts?

Also how do you dispose of diesel in the Grating State of Kalifornia?

If you are afraid to burn it in your engine, ask around in your marina and you'll likely find someone who is interested. I wouldn't be afraid to use it. Lot's of us have old fuel in our tanks. I put together a polishing system which I am glad to have anyway. I also treated my old fuel with an additive which I would recommend if I could remember the name. I'm in Indonesia and my boat is in Hawaii. When need to get back to do buoy runs to satisfy Hawaii state rules, she fires right up and runs strong on fuel easily as old as yours.

[Pete7]

Is it reasonably clear in colour? if so I wouldn't hesitate to use it. Might stop a little short of the bottom of the container, but yes go ahead. Dino juice is already millions of years old.

Pete

[njoynthewater]

Do you not worry about getting water in your diesel tanks through condensation in the near empty tanks? Not sure where the underlined function came from.

[roland stockham]

Deisel does not have a shelf life (I have used some that was more than 15yrs old). If it is contaminated run it through a water seperator/filter. Ideally set up a permenent system wiith a pump and filter so you can cycle fuel from the tank and clean it especially if you use little

[Charlie]

Originally Posted by Minggat

If you are afraid to burn it in your engine, ask around in your marina and you'll likely find someone who is interested. I wouldn't be afraid to use it. Lot's of us have old fuel in our tanks. I put together a polishing system which I am glad to have anyway. I also treated my old fuel with an additive which I would recommend if I could remember the name. I'm in Indonesia and my boat is in Hawaii. When need to get back to do buoy runs to satisfy Hawaii state rules, she fires right up and runs strong on fuel easily as old as yours.

Thanks for the insight. I think I will mix it with some fresh diesel and add cetane boost.

[stormalong]

If you have two tanks empty one and only use one. As other said: Keeping your tank full reduces condensation and is especially important if you don't use much fuel. A good fuel and water separator, like a Racor is more essential in your low usage situation.

[Charlie]

Originally Posted by Pete7

Is it reasonably clear in colour? if so I wouldn't hesitate to use it. Might stop a little short of the bottom of the container, but yes go ahead. Dino juice is already millions of years old.

Pete

Yes very clear. I will run it through a water separator filter before putting it in the tank.

[Charlie]

Originally Posted by roland stockham

Deisel does not have a shelf life (I have used some that was more than 15yrs old). If it is contaminated run it through a water seperator/filter. Ideally set up a permenent system wiith a pump and filter so you can cycle fuel from the tank and clean it especially if you use little

Thanks for the comment

[mike d.]

My fuel sat for 10 yrs ! No issues! No water, no fungus growth, or anything else ! I use Bio-bore ! I would use it as is if it is clear as you say !

[parkstone bay]

In fact, diesel DOES have a shelf life, as the more volatile fractions evaporate off. BUT, when you remember that some of the original designs of diesel engines were intended to run on coal dust, in practice, it's not enough to be concerned about. The thing which is a possible concern is the hygroscopic nature of diesel fuel, so make sure it is well dosed with bug killer, at least double "maintenance" quantity. And to guard against "physical" contamination, (rust, etc), for old diesel, I'd also recommend filtering through coffee filter paper. This does take a long time, but I did it on some really old fuel and I felt it was worth it. TOP TIP: Don't use the coffee filter from home, SWMBO will find out, and you won't have enough life expectancy left to see how long the next 35 gallons last!

[Disailor]

I figure the condensation comes from the water vapor brought in by air pulled in thru the vent hose. I made up 2 clear containers with PVC fittings & filled it with those crystals you use to keep your closet dry. When the crystals start to turn blue I put on the spare one & empty/spread out the blue crystals onto a baking sheet. Once dry they go into a sealed jar. Shake vigorously to break up chunks & save for next switch. 4 years now & no condensation (Penobscot Bay Maine)

[a64pilot]

Originally Posted by Disailor

I figure the condensation comes from the water vapor brought in by air pulled in thru the vent hose. I made up 2 clear containers with PVC fittings & filled it with those crystals you use to keep your closet dry. When the crystals start to turn blue I put on the spare one & empty/spread out the blue crystals onto a baking sheet. Once dry they go into a sealed jar. Shake vigorously to break up chunks & save for next switch. 4 years now & no condensation (Penobscot Bay Maine)

You can actually buy vent line dessicators I believe they are called, they are usually used on storage tanks, but what you have done and are doing will work well. For others they can just buy one.
You are correct on where does the water come from, but to nit pick it’s not condensation, we have a member Maine Sail that proved through experimentation that fuel tanks do not condensate, and he is correct.
However as was stated above Diesel fuel is similar to brake fluid in that they are both hydroscopic, which means that they will absorb water, and when the temperature changes this water will come out of suspension and “bugs” will grow in this fuel / water interface, and of course the water will corrode most metal tanks.
Diesel fuel does have a shelf life. It will both flash off its more volatile ingredients (that’s why it has a smell, those ingredients are evaporating), and it will oxidize.

The shelf life of ULSD is much shorter than the old higher sulphur Diesel.

[atoll]

for many years yachts stopping in wake and midway atolls were filling their tanks with diesel fuel left there in 1944-45!

[Lepke]

Originally Posted by atoll

for many years yachts stopping in wake and midway atolls were filling their tanks with diesel fuel left there in 1944-45!

The diesel formula of that time was much more stable and burned hotter than the crap we have today. In the 1960s I burned a lot of WWII diesel found in mothballed ships. It had been sitting in tanks for 15-20 years.