Caterpillar On-Highway Diesel Engine Fluids Recommendations Caterpillar

Biodiesel is a fuel that can be made from a variety of renewable resources that include vegetable oils, animal fat, and waste cooking oil. Soybean oil and rapeseed oil are the primary vegetable oil sources. The raw oils or animal fats are chemically processed (esterified) to form a fatty acid methyl ester (referred to as FAME). The esterified product (FAME) is biodiesel fuel that can be used in compression ignition engines. Without the chemical processing referred to as esterification, the oils or fats are not suitable for use as fuel in compression ignition engines. In order to use any of the oils or fats listed above as fuel, the oil or fat must be esterified and the water and contaminants removed.

Fuel made of 100 percent FAME is generally referred to as B100 biodiesel or neat biodiesel.

Biodiesel can be blended with distillate diesel fuel. The blends can be used as fuel. The most commonly available biodiesel blends are B5, which is 5 percent biodiesel and 95 percent distillate diesel fuel, and B20, which is 20 percent biodiesel and 80 percent distillate diesel fuel. Note that the percentages are volume based.

U.S. distillate diesel fuel specification "ASTM D975-09a" includes up to B5 (5 percent) biodiesel. Currently, any diesel fuel in the U.S. may contain up to B5 biodiesel fuel.

European distillate diesel fuel specification "EN 590" includes up to B5 (5 percent) and in some regions up to B7 (7 percent) biodiesel. Any diesel fuel in Europe may contain up to B5 or in some regions up to B7 biodiesel fuel.

Engines that are manufactured by Caterpillar are certified by use of the prescribed U.S. EPA and European Certification fuels. Caterpillar does not certify diesel engines to meet emissions standards on any other fuel.

Note: The user of the engine has the responsibility of using the correct fuel that is recommended by the manufacturer and allowed by the U.S. EPA and other appropriate regulatory agencies.

Caterpillar is not in a position to evaluate the many variations of biodiesel and the long term effects on performance, durability, or compliance to emissions standards for Caterpillar products.

Note: In order to align Caterpillar recommendations with the latest revision of "ASTM D7467" specification for B6-B20 blends and to ensure that biodiesel fuel meets defined quality standards, Caterpillar recommendations for acceptable biodiesel blend for most engines have been changed to B20. Details on the use of higher blends are given in this "Biodiesel" section of this Special Publication.

In order to be acceptable for blending, the biodiesel constituent must meet the requirements that are listed in "Caterpillar Specification for Biodiesel Fuel" in this Special Publication, the latest edition of "ASTM D6751", and/or the latest edition of "EN14214".

Distillate diesel fuels that meet the requirements of "Caterpillar Specification for Distillate Diesel Fuel for On-Highway Engines" in this Special Publication, the "National Conference on Weights and Measures "(NCWM) Premium Diesel definition, the latest edition of "ASTM D975 S15" designation; and/or the latest edition of "EN 590", sulfur free designation. No.1-D and No.2-D are examples of fuels that are acceptable for creating biodiesel blends.

Biodiesel blends of B6 to B20 must meet the requirements listed in the latest edition of "ASTM D7467" (B6 to B20) and must be of an API gravity of 30-45.

Biodiesel blends of up to B5 must meet the requirements for the distillate diesel fuel that are listed in the "Caterpillar Specification for Distillate Diesel Fuel for On-Highway Engines" in this Special Publication, the latest edition of "ASTM D975", and/or the latest edition of "EN 590".

Note: The acceptable biodiesel blend level can be increased up to B10±1 for C7 and C9 EPA 2007 model year certified engines and newer, if Cat Diesel Fuel System Cleaner (part Number 343-6210) is used in the first fuel tank fill and at every oil drain interval thereafter. Follow the recommendations provided in the "Fuel Additives" topic in this Special Publication, "Characteristics of Diesel Fuel" article. Also, the Cat Nozzle Cleaner (part number 304-7755) may be used as needed in order to clean the Aftertreatment Regeneration Device (ARD) nozzle.

Note: For 2007 and newer engine models, use of biodiesel blends higher than the recommendations provided in "Caterpillar Specification for Biodiesel Fuel" in this Special Publication may adversely affect engine and aftertreatment components, mainly due to contaminants present in biodiesel. The repair of any engine or aftrereatment components due to such contamination or due to other biodiesel impacts would not be covered under the Caterpillar warranty for materials and/or the warranty for workmanship. Refer to "Additional Maintenance Requirements" topic in this Special Publication, "Biodiesel" article.

Note: For 2006 and older engine models, for use of blends of biodiesel above B20 (20 percent), refer to "Guidelines and potential impacts associated with the use of biodiesel and biodiesel blends" table 3 in this Special Publication for the guidelines and impacts of using high biodiesel blends. Consult your Caterpillar dealer for guidance. A complete Caterpillar S·O·S Services oil analysis program is required when biodiesel or blends of biodiesel that are B20 (20 percent) or above are used.

Either "ASTM D7371" - "Test Method for Determination of Biodiesel (Fatty Acid Methyl Esters) Content in Diesel Fuel Oil Using Mid Infrared Spectroscopy (FTIR-ATR-PLS Method)" or "EN 14078" "- Liquid Petroleum Products - Determination of fatty acid methyl esters (FAME) in middle distillates -Infrared spectroscopy method" can be used for determining the volume percent biodiesel in a biodiesel blend.

For applications running biodiesel or biodiesel blends, it is recommended to use either Cat Diesel Fuel System Cleaner (Part number 343-6210) or Cat Diesel Fuel Conditioner (Part number 256-4968). Cat Diesel Fuel System Cleaner, used as needed or on an on-going basis, is most effective at cleaning and preventing the formation of fuel-related deposits. Cat Diesel Fuel Conditioner can be used to improve fuel stability and can help prevent the formation of fuel related deposits.

Additional maintenance requirements

When biodiesel fuel is used, crank case oil and aftertreatment systems may be influenced. This influence is due to the chemical composition and characteristics of biodiesel fuel, such as density and volatility, and to chemical contaminants that can be present in this fuel, such as phosphorous, alkali, and alkaline metals (sodium, potassium, calcium, and magnesium).

• Crankcase oil fuel dilution can be higher when biodiesel and/or biodiesel blends are used. This increased level of fuel dilution when using biodiesel and/or biodiesel blends is related to the typically lower volatility of biodiesel. In addition, in-cylinder emissions control strategies utilized in many of the latest engine designs may lead to a higher level of biodiesel concentration in the sump. The long-term effect of biodiesel concentration in crankcase oil is currently unknown. The use of Cat S·O·S Services oil analysis is strongly recommended when up to B20 (20 percent) and lower biodiesel blends are used, and required when using biodiesel/biodiesel blends that are B20 or above (when requesting oil analysis, be sure to note the level of biodiesel being used (B5, B20, etc.)).

• Biodiesel fuel contains metal contaminants (phosphorous, sodium, potassium, calcium, and/or magnesium) that form ash products upon combustion in the diesel engine. The ash can accumulate in Diesel Particulate Filters (DPF) that are used in EPA and/or EU 2007 model year certified and newer engines. When B6 to B20 biodiesel fuel is used, ash accumulation in the DPF may be higher than with lower blends. The ash accumulation may cause the need for more frequent ash service intervals and/or cause loss of performance.

• For Cat EPA 2007 model year certified and newer C7, C9 on-highway diesel engines that use the appropriate blend of biodiesel, as set forth above, Caterpillar recommends cleaning the nozzle of the Cat Regeneration System Aftertreatment Regeneration Device (ARD) (also known as the Cat Regeneration System (CRS)) at the regularly scheduled oil change maintenance interval. Refer to the applicable Operation and Maintenance Manual for the procedure for cleaning the ARD nozzle. Failure to perform this additional maintenance will not negatively impact the Caterpillar emissions warranty.

Note: Use of blends higher than B20 is not recommended in engines equipped with DPF devices.

Note: Cat Nozzle Cleaner, part number 304-7755, is recommended for use to clean the ARD nozzle. Refer to the applicable Operation and Maintenance Manual for the procedure for cleaning the nozzle.

Fuel System Deposits

Biodiesel and biodiesel blends are known to cause an increase in fuel system deposits, most significant of which are deposits within the fuel injector. These deposits can cause a loss in power due to restricted or modified fuel injection or cause other functional issues associated with these deposits. Cat Diesel Fuel System Cleaner (part number 343-6210), used as needed or on an on-going basis, is most effective in cleaning and preventing the formation of deposits. Cat Diesel Fuel Conditioner (part number 256-4968) helps to limit deposit issues by improving the stability of biodiesel and biodiesel blends while also hindering the production of new deposits. Therefore, the use of Cat Diesel Fuel System Cleaner and/or Cat Diesel Fuel Conditioner is strongly recommended when running biodiesel and biodiesel blends, especially when using B20 or higher blend levels. Refer to this Special Publication, "Distillate Diesel Fuel", article, "Cat Diesel Fuel Conditioner" and "Cat Diesel Fuel System Cleaner" topics in this Special Publication, "Distillate Diesel Fuel" for additional information.

Consult your Caterpillar dealer for availability of Cat Diesel Fuel System Cleaner and Cat Diesel Fuel Conditioner.

Recommendations

Biodiesel that meets the requirements that are listed in the "Caterpillar Specification for Biodiesel Fuel", the latest edition of "ASTM D6751", or the latest edition of "EN 14214" is not expected to pose major problems when blended with an acceptable distillate diesel fuel at the maximum stated percentages. However, the following recommendations should be followed:

Note: For the purpose of these recommendations, the cautions, guidelines and recommendations applicable to biodiesel (B100) are also applicable to biodiesel blends (B2, B5, B20, etc.). The impacts of biodiesel blends higher than B20 are, in general, more severe than the impacts of biodiesel blends of B20 or lower. Refer to Table 3 of this Biodiesel section for more details.

Note: Fuel storage tanks should be thoroughly cleaned before converting to biodiesel/biodiesel blends. Conversion to biodiesel/biodiesel blends can loosen fuel system and fuel storage tank deposits. Bulk tank continuous filtration unit and dispensing point filters, and onboard engine filters change intervals may need to be shortened for an extended period of time in order to allow for this cleaning effect.

In North America, the use of biodiesel from "BQ-9000" accredited producers and "BQ-9000" certified marketers is required. Look for the "BQ-9000" biodiesel quality accreditation program certification logo that is available to distributors that meet the requirements of "BQ-9000". For more information on the "BQ-9000" program, go to "www.BQ-9000.org".

In other areas of the world, the use of biodiesel that is "BQ-9000" accredited and certified, or that is accredited and certified by a comparable biodiesel quality body to meet similar biodiesel quality control standards, is required.

When using biodiesel fuel, the following recommendations and guidelines should be observed:

1. The oil change interval can be negatively affected by the use of biodiesel. Use S·O·S Services oil analysis in order to monitor the condition of the engine oil. S·O·S Services oil analysis will also help determine the oil change interval that is optimum.

2. Confirm with the filter manufacturer that the fuel filter/filters to be used are compatible with biodiesel. Fuel water separators are preferred when biodiesel is used.

   Note: Cat fuel filters and Cat fuel water separators are compatible with biodiesel fuel.

3. Conversion to biodiesel can loosen fuel system deposits. Fuel filter change intervals may need to be shortened for an extended period of time in order to allow for this cleaning effect when converting used engines to biodiesel.

4. Filter biodiesel and biodiesel blends through a fuel filter with a rating of four microns(c) absolute or less. Filters should be located on the device that dispenses the fuel to the fuel tank for the engine. Filters should be located on the device that dispenses fuel from the bulk storage tank. Series filtration is recommended.

5. In a comparison of distillate fuels to biodiesel, neat biodiesel (B100) typically provides less energy per gallon by 5 percent to 8 percent. Do NOT attempt to change the engine rating in order to compensate for the power loss. This will help avoid engine problems when the engine is converted back to 100 percent distillate diesel fuel. Furthermore, any adjustments to the engine in service to compensate for the power loss may result in violation of emissions regulations such as the U.S. EPA anti-tampering provisions.

6. Compatibility of the elastomers with biodiesel is currently being monitored. The condition of seals and hoses should be monitored regularly. Biodiesel may soften, degrade, or leak from some types of elastomers used in seals and hoses. The higher the biodiesel blend the greater the risk of elastomer related issues.

   1. In general, Cat engines built early to mid 90s use Viton seals and Viton O-rings in the fuel system. Viton is compatible with biodiesel.

   2. Nitrile hoses typically used in some fuel transfer lines are not compatible with biodiesel. Monitor the condition of the hoses and confirm with the hose manufacturer that the hoses are compatible with the biodiesel blend used. If necessary, replace with hoses of compatible materials.

7. Biodiesel may pose low ambient temperature problems for both storage and operation. At low ambient temperatures, biodiesel fuel may need to be stored in a heated building or a heated storage tank. The fuel system may require heated fuel lines, filters, and tanks. Filters may plug and fuel in the tank may solidify at low ambient temperatures if precautions are not taken. Consult your biodiesel supplier for assistance in the blending and attaining of the proper cloud point for the fuel.

   Note: The performance of cold flow improvers can be reduced in the presence of biodiesel fuel. Consult the fuel supplier for appropriate cold flow improvers if needed.

8. Biodiesel can be produced using various renewable sources. The source used can affect product performance. Two of the fuel characteristics affected are cold flow and oxidation stability. Consult your fuel supplier for guidance.

9. Biodiesel has poor oxidation stability, which may accelerate fuel oxidation in the fuel system. Engines with an electronic fuel system operate at higher temperatures. Refer to this Special Publication, "Distillate Diesel Fuel" article, "Aftermarket Fuel Additives", "Cat Diesel Fuel Conditioner", and "Cat Diesel Fuel System Cleaner" topics for information concerning oxidation stability and other fuel additives.

10. Poor oxidation stability of biodiesel can result in long-term storage problems. Biodiesel should be used within a limited time from production. In order to ensure appropriate storage duration, testing of the stored biodiesel is strongly recommended. Tests should include oxidation, acid number, viscosity, and sediments. Tests should be conducted periodically to ensure biodiesel is per specification. Antioxidants are recommended to improve stability of biodiesel. Cat Diesel Fuel Conditioner, part number 256-4968, or appropriate commercial additives are recommended. Consult your fuel supplier for more information.

    1. B20 biodiesel blend can generally be stored up to eight months. Testing of B20 blends is strongly recommended at four months of storage and on a monthly basis thereafter to ensure that the fuel has not degraded.

    2. B100 biodiesel can generally be stored up to four months. Testing of B100 is strongly recommended at two months of storage and every two weeks thereafter to ensure that the fuel has not degraded. The use of appropriate additives is required if B100 is stored more than four months. Consult your fuel supplier for more information.

    3. B100 biodiesel should be stored at temperatures of 30° C (50° F) to 60° C (100° F) above the cloud point.

11. Due to poor oxidation stability and other potential issues, it is strongly recommended that engines with limited operational time either not use biodiesel/biodiesel blends or, while accepting some risk, limit biodiesel to a maximum of B5. Examples of applications that should limit the use of biodiesel are the following: Standby Generator sets and certain emergency vehicles.

    1. Addition of Cat Diesel Fuel Conditioner, part number 256-4968, or an appropriate commercial additive containing antioxidants/oxidation stability improvers, is strongly recommended for standby generator sets and emergency vehicles using biodiesel/biodiesel blends. The conditioner should be added when the engine is fueled or as early as possible when the fuel is delivered and stored. Preferably, the conditioner or additive should be added as soon as possible after the fuel is produced.

    2. For standby generator sets and emergency vehicles that use biodiesel, sample the fuel in the engine tank monthly. Test the fuel for acid number and oxidation stability. If the test results show that the fuel is degraded and that the fuel is not per the appropriate specifications (provided in Table 4 in this "Biodiesel" section), drain the tank, flush with high quality fuel and then refill with high quality fuel following the recommendations provided in this "Fuel" section

    3. For standby generator sets and emergency vehicles that use biodiesel, it is strongly recommended that the fuel oxidation stability is 10 hours or more per "EN 14112" test method.

12. Biodiesel is an excellent medium for microbial contamination and growth. Microbial contamination and growth can cause corrosion in the fuel system and premature plugging of the fuel filter. Consult your supplier of fuel and additive for assistance in selecting appropriate anti-microbial additives.

13. Care must be taken in order to remove water from fuel tanks. Water accelerates microbial contamination and growth. When biodiesel is compared to distillate fuels, water is naturally more likely to exist in the biodiesel.

14. Biodiesel dilution of engine oil may result in oil side leaks due to incompatibility of the seals that are typically used on the oil side. Liner seals and oil cooler seals may be affected by biodiesel dilution. Monitor the condition of the oil side seals and consult your Caterpillar dealer for appropriate replacement if needed.

15. Biodiesel is not compatible with some metals. Biodiesel, in particular B100 and blends higher than B20, will oxidize and form sediments upon long term contact with lead, zinc, tin, copper, and copper alloys such as brass and bronze. Consult your Dealer for more information.

Note: The use of biodiesel at a B2 level improves the lubricity of the final blend by an estimated 66 percent. Increasing the blend level higher than B2 does not improve the lubricity any further.

Seasonal Operation

It is strongly recommended that seasonally operated engines have the fuel systems, including fuel tanks, flushed with conventional diesel fuel before prolonged shutdown periods. An example of an application that should seasonally flush the fuel system is school buses (U.S.).

Perform the following process before shutting down the engine for prolonged periods:

1. Operate the engine until the fuel level in the tank is very low.

2. Refill the fuel tank with high quality conventional distillate diesel fuel.

3. Repeat steps 1 and 2 a minimum of two times before the engine is shut down for prolonged periods.

If distillate fuel is not available to operate the engine as described above, while accepting some risk, limit biodiesel to a maximum of B5. Follow the recommendations provided in this section and the guidelines given below to reduce the risk:

• Addition of Caterpillar Diesel Fuel Conditioner, part number 256-4968, or an appropriate commercial additive containing antioxidants/oxidation stability inprovers, is strongly recommended prior to engine shut down for prolonged periods. The conditioner should be added when the engine is fueled. Preferably, the conditioner is added to the fuel as soon as possible after the fuel production.

• Addition of Caterpillar Diesel Fuel System Cleaner, part number 343-6210, or an appropriate commercial cleaner is recommended when the engine is first operated after the prolonged shutdown period and preferably for a total of two tanks of fuel. Follow the recommendations provided in the Caterpillar Diesel Fuel System Cleaner section in the "Fuel" article in this Special Publication.

Consult your Caterpillar dealer for the availability of Caterpillar Diesel Fuel Conditioner and Caterpillar Diesel Fuel System Cleaner.

Biodiesel Specification

Biodiesel fuel used that is used for blending must meet the requirements in the following table.

Referenced Documents

• "ASTM D6751 Standard Specification for Biodiesel Fuel Blend Stock (B100) for Middle Distillate Fuels"

• "EN 14214 Automotive fuels - Fatty acid methyl esters (FAME) for diesel engines - Requirements and test methods"

• "ASTM D7467 Standard Specification for Diesel Fuel Oil, Biodiesel Blend (B6 to B20)"

• "ASTM D975-08a Standard Specification for Diesel Fuel Oils" (includes requirements for B5 and lower biodiesel blends)

• "EN 590 Automotive fuels - Diesel - Requirements and test methods" (includes requirements for B5 and lower biodiesel blends)

• "EN 14078 Liquid petroleum products - Determination of fatty acid methyl esters (FAME) in middle distillates - Infrared spectroscopy method"

• "EN 14104 Fat and oil derivatives - Fatty Acid Methyl Esters (FAME) - Determination of Acid Value"

• "ASTM D664 Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration"

• "ASTM D6469 Standard Guide for Microbial Contamination in Fuels and Fuel Systems"