Commercial Diesel Engine Oils Lubricant Specifications
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Illustration 68
Diesel engine oils CD, CD-2, and CE will not be API authorized categories after 1 January 1996. Caterpillar will only reference those categories that are authorized by
the API. Table 21 summarizes the status of the categories.
Table 21
Current Obsolete
CF CC, CD
CF-21 CD-2
1
CF-4, CG-4 CE
1
CD-2 and CF-2 are categories for two-cycle diesel engines. Caterpillar does not sell engines that utilize
CD-2 and CF-2 oils. Note: CF is not the same classification as CF-4. API CF oils are only recommended for
Caterpillar machine engines with noncurrent precombustion chamber fuel systems PC.
In previous editions of this document, Caterpillar referred to the US Military Oil Specifications MIL-L-XXXX and to the European CCMC oil specifications. These
specifications do not provide identical performance to API CF-4 or API CG-4 engine oils. Caterpillar will not make reference to military specifications or CCMC
specifications in this document.
TransmissionDrive Train Oil Transmissiondrive train oils are classified by the TO-4 specifications. The
specifications are developed by Caterpillar for use in Caterpillar transmissions and for use in Caterpillar final drives.
Gear Oil Gear lubricants are classified by the API service classification and by the SAE viscosity
grade that is defined in SAE J306.
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Grease The classifications for grease are based on the ASTM D2718 worked penetration
characteristics, which are given a defined consistency number. Terminology
Certain abbreviations follow the nomenclature of SAE J754. Some classifications follow SAE J183 abbreviations. Definitions that differ from Caterpillar definitions will
assist you when you purchase lubricants. Recommended oil viscosities can be found in the table of Lubricant Viscosities that is in this document.
Cetane Number During average starting conditions, direct injection engines require a minimum cetane
number of 40. A higher cetane value may be required for high altitude operation or for cold weather operation.
Filterability Clean fuels should have no more than a 0.10 percent concentration of sediment and of
water. Fuel that is stored for extended periods of time may form solids due to oxidation. This could cause filtering problems.
Pour Point A fuels pour point should be at least 6°C 10°F below the lowest ambient temperature
that is required for engine start-up and for engine operation. To operate the engine in extremely cold weather, No. 1 fuel or No. 1-D fuel may be necessary because of these
fuels lower pour points.
Cloud Point To prevent the fuel filter elements from plugging with wax crystals, the cloud point
should be below the lowest ambient temperature that is required for engine start-up and for engine operation.
Viscosity Fuel viscosity affects the lubrication of fuel system components. Fuel viscosity also
affects fuel atomization. The viscosity limits that are provided in Table 20 address these effects.
Additives Fuel additives are not generally recommended for the specified fuels that are listed.
Fuel additives are not needed for the specified fuels that are listed. Cetane improvers
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can be used for the direct injection engine requirements, as needed. Biocides may be needed in order to eliminate microorganism growth in storage tanks. In cold conditions,
treatment for entrained water may also be necessary.
Consult your fuel supplier about the use of additives in order to prevent incompatibility between additives that are already in the fuel and additives that will be used.
Fuel Sulfur The percentage of sulfur that is in the fuel will affect the engine oil recommendations.
Fuel sulfur is chemically changed during combustion. This chemical change causes the formation of sulfurous acid and of sulfuric acid. These acids cause corrosive wear to
metal surfaces. Sulfur oxides that are formed during combustion also produce particulate exhaust emissions.
Certain additives that are used in lubricating oils contain alkaline compounds which neutralize the acids in combustion gases. This minimizes corrosive wear. The measure
of this reserve alkalinity in a lubricating oil is known as the oils Total Base Number TBN.
In the USA, 0.05 percent diesel fuels have been used in all on-highway truck engines since 1 January 1994. This low sulfur diesel fuel was mandated as a means of directly
reducing particulate emissions from diesel truck engines. This low sulfur fuel will also be used in Caterpillar machines when low emissions are needed or when supply
sources provide this type of fuel. Caterpillar has not seen any detrimental effects with 0.05 percent sulfur fuel in Caterpillar machines.
Periodically request information about fuel sulfur content from your fuel supplier. Fuel sulfur content can change with each bulk delivery.
NOTICE Residual, Blended, or Heavy fuels must not be used in Caterpillar diesel engines. Severe component wear and component failures will result if residual type fuels
are used.
Fuel Specifications