Diesel engine designs striving to increase engine performance
have made great advancements in engine fuel delivery to the
combustion chamber. Today's diesel engine is quieter, smoother,
and more powerful. But today's diesel engine owners are
overlooking one important factor. The quality of today's diesel
fuel has not advanced at the same rate as the engine
improvements.

Diesel fuel begins to deteriorate as soon as it is produced.
Within 30 days of refining, all diesel fuel regardless of
brand, goes through a natural process called re-polymerization
and oxidation. This process forms varnishes and insoluble gums
in the fuel by causing the molecules of the fuel to lengthen
and bond together. These components now drop to the bottom of
the fuel tank and form asphaltene also known as diesel sludge.
The fuel begins to turn dark in color, smell bad, and in most
cases causes engines to smoke. The engines smoke because some
of these clusters in the early stages are small enough in size
to pass through the engine filtration and into the combustion
chamber. As these clusters increase in size, only part of the
molecule gets burned. The rest goes out the exhaust as unburned
fuel and smoke. With increases in cluster size they begin to
reduce the flow of fuel by clogging filters. The filters only
address the symptom and not the cause.

It is estimated that eight out of every ten diesel engine
failures have been directly related to poor quality and
contaminated fuel. The build-up of contaminates in the fuel
systems and storage tanks can quickly clog filters, thus
resulting in engine shut down, fuel pump wear, and diesel
engine damage.

Understand that most fuel has some amount of water in it from
either condensation or vents. This threat requires that we
realize the added burden placed upon diesel fuel as opposed to
gasoline. Gasoline acts as a fuel only. Diesel fuel, on the
other hand, also must cool and lubricate injection system
parts. These parts are engineered to very close tolerances - up
to 0.0002 of an inch - and any contamination means rapid part
wear. Water displaces the diesel fuel. When the fuel is
displaced wear occur because lubrication is now absent.

Water that enters the combustion chamber results in even more
serious damage. When it comes in contact with the heat of the
combustion chamber (in excess of 2000 degrees F), it
immediately turns to steam and often explodes the tip of the
injector. Water causes corrosion of tanks, lines, injectors,
and greatly reduces combustibility.

Other areas of concern include the producing more exhaust
emissions and effecting EPA standards.

Bacteria also present a serious problem. Bacteria feed on
nitrogen, sulfur, and iron that may be present in the fuel or
tank.

Then there are algae. There are absolutely no algae in diesel
fuel. You may have fungus and microbial contamination but no
algae. This is a misnomer for diesel sludge. So if you have a
diagnosis of ALGAE and add a biocide, you have done two things,
1) found a mechanic that is wrong and 2) done nothing to fix the
problem.

Why is there so much bad fuel?

The number one reason is due to the increased popularity of
diesel power and the accompanying increased demand for more
diesel fuel. There was a time when diesel fuel remained in the
refinery storage tanks long enough to naturally separate and
settle, allowing the clean fuel to be drawn off. Now with
increased demand, diesel fuel never remains stationary long
enough for settling, and the suspended water and solids are
passed on to you, the user.

The change in refinery techniques is another problem. In order
to get more products per dollar; diesel fuel is now being
refined from more marginal portions of the crude oil barrel.
This results in a lower-grade product that is inherently
thicker and contains more contamination.

Thirdly, current fuel distribution methods also have a negative
impact on the condition of the fuel at the time of delivery. In
many cases, brokers control fuel sales to major distribution
terminals and determine delivery dates. There is no telling how
long that fuel has been in the distribution network and how many
times it has been transferred. Seldom do these distributors
filter the fuel as they transfer it.

The solution: Multifunctional diesel additive packages and
hardware.

For your single vehicle or fleet the improvement of fuel
quality by the use of additives and current technology is
always a good choice.

Many diesel fuel additive packages address the key issues with
respect to fuel performance; some improve fuel economy,
increase lubricity, improving cold flow, and improve cetane
number. And some only address the issue of rust and corrosion,
but all should be considered.

Most diesel fuel additives contain combustion improvers that
release oxygen during the compression stroke. This allows
combustion to start sooner, providing for a more complete fuel
burn. A more complete burn provides all the power your fuel and
engine is capable of producing. As combustion improvers and you
get a smoother running engine, an increase in horsepower that
improves fuel economy and the reduction in black smoke
emissions.

Cetane is a performance rating of a diesel fuel, a higher
cetane number or cetane rating indicates greater fuel
efficiency. The fuel's cetane influences, duration of white
smoking after start-up, drivability before warm-up, and
intensity of diesel knock at idle. Increase the cetane number
of a fuel and you have improved performance.

In diesel fuel systems, the fuel provides lubrication for the
fuel pump and injectors. A fuel with poor lubricity can cause
excessive wear and premature failure of these components.
Improve lubricity and extend engine life.

Diesel fuels have pour points (the lowest temperature at which
an oil or other liquid will pour under given conditions) within
the range of normal winter temperatures. As a fuel approaches
its pour point, paraffin in the fuel form wax crystals that
prevent it from flowing. Flow-improver additives modify the wax
crystals, lowering the pour point of the fuel and give better
cold weather performance.

For on-sight storage tanks other issues must be looked at.
On-sight storage tanks always have a small amount of the first
gallon of fuel ever put in them, unless it is drained 100% and
cleaned. So adding new, fresh fuel always has a bit of the bad
added to it every time fuel is purchased. Diluting the bad with
good over time is a loosing battle. The fuel will always be bad
fuel until the core problem is addressed

The order of treatment for fuel related problems should always
begin with a determination of whether there is water in the
fuel and if the fuel has microbes (fuel bugs) in it. Water
Paste and Fuel Test Kits can be used for this stage of
maintenance. If microbes are detected, then the use of biocides
is needed. Biocides have no effect on and will not eliminate the
sludge problem. Biocides kill bacteria, that's all!

The water issue should always be remedied first by the use of
fuel water separators on the tank or on the equipment. Next a
multifunctional chemical additive should be added to improve
fuel performance and then if needed a problem specific additive
to dissolve diesel sludge and or a rust inhibitor to protect
steel tanks. For long-term prevention, the use of magnet fuel
conditioners is recommended. These devices continually reverse
the re-polymerization of the fuel during circulation and reduce
the need for ongoing additive use. All the needed cures are
available from Dieselcraft Fluid Engineering at
www.dieselcraft.com
Conclusion

There is no good time to find out that your engine won't
operate or that half its life span is gone prematurely because
of contaminated or poor quality diesel fuel. Since no one can
predict a breakdown, the only safe method is prevention.

Realize now that you do have a problem, and manage it now, or
deal with the unexpected catastrophe and reduced equipment life
that comes at the absolutely wrong time and is not in the
budget!


About The Author: John T. Nightingale President of Dieselcraft
Fluid Engineering, Auburn CA 95604,manufactures of diesel fuel
purification systems. http://www.dieselcraft.com