TSB: MO-2006-05-04
Date: 05/05/2006
Subject: Use of Biodiesel Fuel with AMSOIL Motor
Oils Technical Service Bulletin
Product Description: ALL AMSOIL Motor Oils
OBJECTIVE:
To explain to AMSOIL Dealers the nature of biodiesel
fuel and its effects on engine operation and
lubricant service life.
TECHNICAL DISCUSSION:
Definition of Biodiesel (1)
Biodiesel is a mixture of methyl esters of long
chain fatty acids like lauric, palmitic, steric,
oleic, etc. It is produced by the
transesterification of animal fats and vegetable
oils. Typical examples are rapeseed oil, canola oil,
soybean oil, sunflower oil, palm oil and its
derivatives from vegetable sources. Beef and sheep
tallow and poultry oil from animal sources and
cooking oil are also the sources of raw materials.
The chemistry of conversion to biodiesel is
essentially
the same. Oil or fat react with methanol or ethanol
in the presence of catalyst sodium hydroxide or
potassium hydroxide to form biodiesel (methylesters)
and glycerin.
Biodiesel is not the same as those vegetable oils or
animal fats. The properties of biodiesel must adhere
to the industrial standard (ASTM D6751). Raw
vegetable oils and animal fats do not meet ASTM
D6751 specifications.
Biodiesel can be blended with petroleum fuel to
create biodiesel blends. These blends are designated
as Bxx, where “xx” is the percentage of biodiesel in
the blend. For example, a B5 blend is 5% biodiesel
and 95% diesel fuel.
Advantage of Using Biodiesel
The physical and chemical properties of biodiesel
are similar to petroleum based diesel in terms of
operation of compression ignition engines.
Therefore, biodiesel can be used in diesel vehicles
without expensive alterations to the engine or fuel
system. The other major benefits of using biodiesel
include the following:
-
Biodiesel is biodegradable, non toxic and
essentially free of sulfur and aromatics.
-
Improved lubricity.
-
High cetane number.
-
Improved conductivity, particularly for Ultra Low
Sulfur fuel.
Disadvantage of using Biodiesel
Lower Energy Content (2)
The energy content of neat biodiesel fuel is about
eleven percent (11%) lower than that of petroleum
based diesel fuel, resulting in a power loss in
engine operation. Engine adjustment for the power
losses could lead to violation of EPA antitampering
provisions.
Engine Operation Problems (2)
Neat biodiesel and higher percentage biodiesel
blends can cause a variety of engine performance
problems, including filter plugging, injector
coking, piston ring sticking and breaking, elastomer
seal swelling and hardening/cracking and severe
engine lubricant degradation. There is very little
information on the use of biodiesel with engine
durability over the mileage and operating conditions
of heavy-duty diesel engines. More information is
needed.
Storage and Handling
Biodiesel fuels have shown poor oxidation stability,
which can result in long-term storage problems. When
biodiesel fuels are used at low temperatures,
filters can be plugged and the fuel can thicken.
Sub-standard biodiesel fuel might contain glycerin
that can precipitate out of the biodiesel fuel and
plug the filter at low temperatures.
Biodiesel fuel is an excellent media for microbial
growth, which may cause operation problems, fuel
system corrosion and premature fuel filter plugging.
Emissions
Oxygen and other biodiesel characteristics can
contribute to increased NOx emissions.
Engine Manufacturer's Position (3-12)
Generally, diesel engine manufacturers accept
blending biodiesel fuels up to 5% with petroleum
diesel(B5). Concentration beyond 5% could have
adverse effects on the engine performance and the
fuel system integrity and durability.
Most OEMs express concern regarding the service life
of lubricants when higher concentrations of
biodiesel are used.
Ford Motor Company:
Ford is advising that any of their vehicles
powered by a diesel engine, regardless of
manufacturer, may exhibit engine or fuel system
problems when using fuels with greater than 5%
Biodiesel. Any problems when using fuels containing
more than 5% Biodiesel should be referred to the
fuel manufacturer. Ford only recomends using fuels
containing no more than 5% Biodiesel (B5) in their
diesel powered vehicles. In addition, as per World
Wide Fuel Charter (WWFC) catagory 1-3, fatty acid
methyl esters (FAME) must meet EN14214 and ASTM D
6751 specifications. This was published as Broadcast
Message 0884, 3626
Cummins:
“The oil change interval can be affected by the use
of biodiesel fuels and some applications may require
shortening intervals to half of the diesel
equivalent.”
International:
“The use of higher biodiesel blends may reduce the
engine service life and drain intervals.”
Volvo Truck:
“When the customer wishes to use fuels based on
vegetable oils, we recommend that the oil changing
intervals be halved in order to eliminate the risk
of dilution of the engine oil.”
Effect of Biodiesel on Lubricants (13)
- Fuel dilution resulting in viscosity reduction.
- Sludge and varnish formation.
- Depletion of alkalinity reserve in the oil
indicated by total base number decrease.
- Total acid number increases more rapidly,
indicating oil degradation probably from more NOx
acid formation.
- Certain metals such as copper and lead leached
from bearing due to biodiesel fuel in the lubricant.
-
Oil filters plugging from sludge.
RECOMMENDATIONS:
AMSOIL Motor Oil extended drain interval
recommendations do not apply to vehicles using
biodiesel fuels at any mix ratios with petroleum
diesel. When using biodiesel fuels at any mix ratio,
follow the OEM recommended oil drain interval.
REFERENCES:
1.www.biodiesel.org
2.http://www.enginemanufacturers.org/info/division.asp?ID=65
3.Caterpiller Machine Fluids Recommendation,SEBU 6250-14, April 005, Page 53-56
4.http://www.cummins.com/cmi/
5.http://www.detroitdiesel.com/Support/On-Highway/Manuals/Lubricants_Fuels_Coolants/
index.asp
6. www.biodiesel.org/resources/fuelfactsheets/standards_and_warranties.shtm
7.http://www.deere.com/en_US/ag/servicereport/tips/tractors/9000/biodiesel_in_John_Deere_Tractors.html
8.http://www.vw.com/contactus/faqs.html
9.International, Technical Service Information, TSI-05-12-21
10. https://www.fleet.ford.com/showroom/environmental_vehicles/biodieselTechnology.asp
11. General Motor, AltFuels, Fleet and Commercial,2004, Vol 5, Issue 1
12. Volvo Truck Corporation, Service Bulletin, Group 170, No. 44, Version 1, Page 3
13.
www.eeci.net/archive/biobase/B10577.html
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