826709 6 Mercruiser NUT, (#10-32) Stainless Steel

Diesel Engine Oil
For more information, refer to Special Publication, SEBU6251, "Cat Commercial Engine Fluids Recommendations".Cat Diesel Engine Oil (Cat DEO)
Cat oils have been developed and tested to provide the full performance and service life that has been designed and built into Cat engines. Cat oils are currently used to fill Cat Diesel Engines at the factory. These oils are offered by Cat dealers for continued use when the engine oil is changed. Consult your Cat dealer for more information on these oils.Due to significant variations in the quality and in the performance of commercially available oils, Caterpillar makes the following recommendations:
Table 1
Cat Lubricants Viscosity Grade
Diesel Engine Oil-Ultra Low Sulfur Cat DEO-ULS SAE 15W-40
Cat DEO-ULS SYN SAE 5W-40
Cat Cold-Weather DEO-ULS SAE 0W-40
Diesel Engine Oil Cat DEO SAE 15W-40
Cat DEO SYN SAE 5W-40 Note: Cat DEO and Cat DEO-ULS multigrade oils are the preferred oils for use in this Cat Diesel Engine.Commercial Oil
Note: Non-Cat commercial oils are second choice oils for your engine.
Caterpillar does not warrant the quality or performance of non-Cat fluids.
The three current Caterpillar ECF specifications are: Cat ECF-1-a, Cat ECF-2, and Cat ECF-3. Each higher Cat ECF specification provides increased performance over lower Cat ECF specifications.A commercial oil must meet the following standards to be considered an equivalent of a Cat Diesel Engine Oil:
Table 2
Cat Engine Crankcase Fluids (ECF) Definitions
Cat Performance Requirement Cat ECF Specifications Requirements
Cat ECF-3 API CJ-4 Oil Category performance requirements
Cat ECF-2 API CI-4 / CI-4 PLUS Oil Category performance requirements
Passing standard Cat C13 engine test per API requirements
Oils of sulfated ash > 1.50 percent are not allowed
Cat ECF-1-a API CH-4 Oil Category performance requirements
For oils that are between 1.30 percent and 1.50 percent sulfated ash, passing one more Cat 1P SCOTE test ("ASTM D6681") is required
Oils of sulfated ash > 1.50 percent are not allowed In selecting oil for any engine application, both of the following must be satisfied: the oil viscosity and the category of oil performance or the specification for oil performance . Using only one of these parameters will not sufficiently define oil for an engine application.The proper SAE viscosity grade of oil is determined by the following temperatures: minimum ambient temperature during cold engine start-up and maximum ambient temperature during engine operation.Refer to Table 3 (minimum temperature) to determine the required oil viscosity for starting a cold engine.Refer to Table 3 (maximum temperature) to select the oil viscosity for engine operation at the highest ambient temperature that is anticipated.Note: Generally, use the highest oil viscosity that is available to meet the requirement for the temperature at start-up.
Table 3
Lubricant Viscosities for Ambient Temperatures
for Cat Diesel Engines
Oil Type and Performance Requirements Viscosity Grade °C °F
Min Max Min Max
Cat Cold-Weather DEO-ULS
Cat ECF-1-a
Cat ECF-2
Cat ECF-3 SAE 0W-40 −40 40 −40 104
Cat DEO-ULS SYN
Cat DEO
Cat ECF-1-a
Cat ECF-2
Cat ECF-3 SAE 5W-40 −30 50 −22 122
Cat DEO-ULS
Cat DEO SAE 10W-40 −18 50 0 122
SAE 15W-40 −9.5 50 15 122 Note: A cold soaked start occurs when the engine has not been operated recently, allowing the oil to become more viscous due to cooler ambient temperatures. Supplemental heat is recommended for cold soaked starts below the minimum ambient temperature. Supplemental heat may be necessary for cold soaked starts that are above the minimum temperature depending on factors such as parasitic load.Total Base Number (TBN) and Fuel Sulfur Levels
The use of Cat S O S Services oil analysis is recommended strongly for determining oil life.The minimum required Total Base Number (TBN) for oil depends on the fuel sulfur level. The TBN for new oil is typically determined by the "ASTM D2896" procedure. For direct injection engines that use distillate fuel, the following guidelines apply:
Table 4
TBN recommendations for applications in Cat engines(1)
Fuel Sulfur Level percent (ppm) Cat Engine Oils TBN of Commercial Engine Oils
≤0.05 percent (≤500 ppm) Cat DEO-ULS
Cat DEO Min 7