Dirty Diesel Fuel

[Perfect Fuel]

I replied to another post concerning diesel fuel clogging filters and issues with dirty fuel and thought a bit of clarification might help. I just joined this forum because I was reading some misinformation about diesel fuel and filters.
I don't want this response to be conceived as a spam note.
My business is keeping diesel fuel clean. I do this for some of the largest corporations in the world, including one's that make yellow and green diesel engines and related generators.
Diesel fuel goes dark because of a process called re-polymerization. This happens because diesel fuel contains fuel that has been "cracked". Cracked fuel has carbon molecules that have a positive and negative charge. The molecules chain together over time. This chaining action slowly results in dark fuel. As the carbon chains become larger, they settle to the bottom of the tank as sludge. If water is introduced into the tank via condensation, moist air or simply a loose leaking fuel cap, microbe activity begins. Algae is not possible in a fuel tank because algae requires light to grow. However a microbe loves water and will flourish in a tank with moisture. Another issue with water is microbes give off a discharge that lowers the Ph of the water, thus turning the water to acid. Not good for tanks and lines.
If a tank gets sludge in it, a fuel additive will only help marginally. The tank needs to be properly cleaned; the fuels polished and then keep a good quality additive in the fuel (Nanolube or Algae-X AFC 705 work well).
Fuel filters, when rated have a spec. to catch 50% of the material at a specific micron size. A 10 micron filter (a micron is 1 millionth of a meter) will catch at least 50% of everything over 10 micron's. Fuel sludge will clog a filter very quickly if the fuel pick-up sucks sludge.
When fuel is dark, the engine will be more difficult to start because re-polymerized fuel does not blend well with oxygen. Thus difficult starting, and excessive smoke occur.
Modern diesel engines run very tight tolerances in the pumps and injectors. Dirty fuel going through these parts acts like sand. The removal of virtually all sulfur from modern fuels (15 PPM) also requires the fuel to be clean as the fuel now acts as the lubricant for pumps and injectors instead of the sulfur.
Bottom line, keep the fuel clean or it will destroy a good engine quickly.
Sorry to get longwinded here.
Email me for more info if you like. I am happy to share.

[mrutkaus]

Thanks for the info, everything helps.

Mike

[cowpie1]

I got sold on the Algae-X unit I installed in the fuel line on my Cummins ISX. I also started using PRI-D at around the same time. I have not had any fuel related issues since.

[Toyboy]

How long can you keep your fuel before these problems start. This is my first diesel (Kubota 2230) and all this is new to me. I've heard about the fuel gelling in truck tanks but never gave a thought to these small tractors. My machine will get it's share of work cutting in the summer and will use several tanks of fuel. But a full tank in fall will probably get me through the winter blowing snow unless we have one of those winters from **** w/above average snow. I would usually keep a 5 gallon can in reserve if needed, but with all the issues with old fuel that's out. Now you got me freaked out worrying about additives and length of time fuel is in my tank..... bummer

[bp fick]

Not much for the average TBN person to sweat about.

Here are my thoughts. I read a lot here about diesel algae, diesel storage, etc. By guessimate, and I grant it is only by observation, most the folks here with cuts and subcuts are less than 100 hour per year people, with many being 50 hour or less in tractor time. That just is very little fuel at .6 gal per hour average. These are approximated averages, of course. But the point remains. I fill my can, what? Once a month? Maybe.

Unless for some reason one spends weeks at a time at home, then one passes a fuel mart, selling fresh diesel, every time one leaves the house. It is virtually unavoidable. This means that folks can buy diesel almost anytime, dozens of times a week, with no special effort, no special trip required. All one has to do is to remember to put the plastic can in the truck. OK, remembering things does get harder with age!

I don't bother with having diesel storage. With access to fresh diesel so readily available and requiring no special effort, it just isn't difficult to always have fresh diesel. That's just my .02
Your mileage may vary.

[Ken45101]

How long can you keep your fuel before these problems start. This is my first diesel (Kubota 2230) and all this is new to me. I've heard about the fuel gelling in truck tanks but never gave a thought to these small tractors.

Fuel "jelling" happens in cold weather. Cold weather diesel is different from summer diesel. The fuel supplier should add an anti jelling additive. If not, or to be on the safe side, you can add a winter supplement yourself (e.g. Power Service for cold weather).

The algae growth is a warm weather issue. Again, there are additives that are supposed to reduce it. Probably best not to store diesel in the sun where it gets hotter. I store mine inside the barn. But you will see plenty of farmers with outside tanks.

FWIW, my farm supplier claims they add Power Service and he tells me it should be good for at least a couple of years. I do not plan to test that statement however. But then I usually get 2-4 deliveries per year (I just got 180 gallons delivered this week.)

Ken