Useful life of diesel fuel

[pvid08]

How long can diesel sit in the tanks before it goes bad? I topped off the tanks and added the fuel stabilizer when I winterized at the end off last season (end of November). I went for a ride on Memorial Day (engine ran well). Burned about 5 gallons.
I may not be able to get out again till mid August. Will the fuel still be usable or does it start to break down? Should I add some more fuel stabilizer?


Peter

[Mistress]

Though I probably wouldn't recommmend it, I've used unstabilized diesel that was well over 1 year old. Gas used to hold up half-way decent before all the newer formulas came out. Since diesel is ignited by heat (compression) it's not nearly so sensitive.

I'm still using deisel in my boat I filled it with last Spring on top of fuel that came with the boat from Florida. I did stabilize it..no problems whatsoever.

Water is a bigger problem with diesel. It allows stuff to grow and water raises hell with the fuel system in general.

I wouldn't add more stabilizer than is recommended on the product label.

[Pedlyr]

One problem with long term storage of diesel fuel in a stationary vessel is algae.

In the warmer months or climates it grows inside the tank with the fuel. So when you decide to fire up the ol' girl for a spin and there is a 4 ft chop on, you shake everything up that can lead to clogged filters. This is when a good secondary fuel filter system (like a Racor) is a must.

This condition can also develop in the Fall when the weather turns cold and the algae dies and settles to the bottom of the tank.

Keep plenty of spare elements (they don't go bad) onboard and monitor the crap in the secondary bowl. Some have suggested other style set-ups than a clear bowl, like with a Racor or Dahl style unit. I personally do not like them just for this fact. You can't monitor what is going on if you can't see it. Plus, you can always drain stuff like water out the bottom.

With the proper filtration, most diesel engines will run trouble free. Just keep the fuel clean and you should be all set.

[Diesel Shamrock]

The worst part of diesel setting is the expansion and contraction of the tanks/fuel/air. This allows moisture to be drawn in by the tank heating up during the day and cooling off at night drawing the night’s cool moist air in the tank. The less full the tank is the greater risk of this happening is. Once this happens enough, you can get a layer of water on the bottom of your tanks once you have this layer of water you can then get a form of algae that then thrives in your tank. Then once this happens you get the dreaded black slime in your fuel filters. If diesel is going to set for a while I would get a fuel additive with an algae killer/preventer and make sure you have a couple of sets of fuel filters when you go to use it again. I have run fuel that had algae in it and then treated. It plugs filters up fast, some times in less than a day but never experienced any fuel system problems other than having to change the filters

[pvid08]

Thanks all for the info.

Peter