Biodiesel Precautions

Some facts concerning biodiesel and its usage.

1. Engine Warranty: The use of biodiesel and biodiesel
blends has not been approved by all engine manufacturers. Your use of
the fuel may effect your warranty; therefore you should check your
owners manual or with your engine manufacturer before using biodiesel
blends over B5. The NBB's standards and warranties page has a list of engine manufacturers' satements about the use of biodiesel in their engines. Manufacturer generally require that only ASTM or BQ 9000 fuel is used; high blends ( e.g. B50) of good-quality biodiesel have been used extensively in many different types of diesel engines without modifications, or problem.

A few links directly to manucaturers pages: Case IH
Ford
Daimler-Chrysler
 General Motors
Caterpillar
Cummins ,

or visit this page combining all of the manufacturers positions on biodiesel in their engines.

2. Solvent Properties: Biodiesel, in addition to being fuel, is an effective solvent, and will act accordingly. This means that:

a. Biodiesel will dissolve existing solids—created through usage of
petroleum ("petroleum") diesel—in your vehicle's fuel system. These
solids will clog your vehicle's fuel filter. When this happens depends
on many factors, but can be recognized by the following symptoms: power
loss, engine sputtering, difficulty starting, and poor fuel mileage.
When you notice these symptoms, you will have to replace your vehicle's
fuel filter (possibly more than once, depending on the amount of
petroleum solids in the fuel system). The biodiesel-coop.org recommends
keeping at least one spare fuel filter on hand at all times. Clogging
of fuel filters also occurs with old fuel storage containers that
contained petroleum diesel. When dealing with such large fuel tanks,
fuel filters may have to be changed many times, and cleaning of the
tank before biodiesel usage may be a more suitable alternative.

b. Biodiesel will, over time, dissolve most types of paint. For
this reason, the biodiesel-coop.org recommends keeping a clean, soft,
dry rag on hand when fueling, to gently wipe off any spillage. When the
rag becomes soaked with biodiesel, put it in a dark, closed storage
container to await proper disposal. Do not leave fuel-soaked rags
crumpled up in the sun. Under such conditions, the rags are prone to
spontaneous combustion due to oxidation and the heat generated during
that process.

c. Biodiesel will degrade rubber components in older vehicles' fuel
systems faster than petroleum diesel. These components include some
hoses, seals, and o-rings. Most diesel vehicles made after 1993 use
synthetic components, eliminating this problem. Please contact the
manufacturer for answers on specific parts. Should your rubber
components need replacement, we recommend viton substitutes. Call us
for more information.

3. Cold Weather Properties: Depending on its feedstock,
biodiesel can gel at temperatures as high as 40 degrees Fahrenheit or
higher without added anti-gel. If you operate in cold weather take
precautions to prevent gelling which can include blending with
petroleum or the use of cold weather treatments. This is especially
recommended for vehicles with electronically-controlled,
highly-sensitive fuel injection systems, such as those found in
Volkswagen TDIs and Chevrolet/GMC Duramaxes.

5. Vehicle Emissions and Performance: Because every engine
is different, we make no claims about the
emissions or performance when burning biodiesel fuel. Biodiesel will
not have the same effects on every vehicle. Because the BTU value of
biodiesel is slightly less than that of petroleum diesel no. 2, a small
loss of power and fuel economy is to be expected, although this is
mitigated by biodiesel's higher lubricity and cetane number.

6. Biodiesel Storage: Biodiesel should not be stored more
than 6 months without topping off or cycling. Biodiesel can oxidize
when exposed to air and light for extended periods, resulting in a
"rancid" fuel that can have negative effects on your vehicle's
performance. Biodiesel needs to be stored properly, in a dark
container, away from air and water. Use a filter with a water
separator. Like diesel, biodiesel can attract bugs and biological
contamination. The potential for contamination should be taken very
seriously, and guarding against it is the member's responsibility.
Large fuel containers must be vented properly.

7. Fuel Additives: Biodiesel, in this document, is defined
as 100% biodiesel (B100) and biodiesel blends are identified by the
blend concentration. For example B20 contains 20% biodiesel and 80%
petroleum diesel. If you would like to use an additive in your fuel,
for whatever reason, we recommend you contact us for recommendations.
If you plan on blending biodiesel with petroleum diesel, remember: the
better quality the diesel, the better the blend. Environmentally if you
must blend with petroleum diesel use D975 specification fuel and try to
only use low sulfur fuel.

In addition to the above precautions and disclaimers, PCBC reminds you that many mechanics have not heard of
biodiesel, nor worked on vehicles using it as fuel.