There 'are hundreds of commercial crankcase oils marketed today. Lubricants marketed for heavy duty diesel service
consist of refined crude oil to which has been added additives compounded to meet the desired engine performance
levels. Oil additive selection is based on evaluations conducted by the oil supplier; therefore, satisfactory OIL QUALITY is
the responsibility of the oil supplier. (The term oil supplier is applicable to refiners, blenders and rebranders of petroleum
products, and does not include distributors of such products.) Experience has shown that oil performance in commercial
heavy duty diesel service applications varies from brand to brand.
Obviously engine manufacturers or users cannot completely evaluate the hundreds of commercial oils; therefore the
selection of a suit- able lubricant in consultation with a reliable oil supplier, strict observance of his oil change
recommendations (used oil sample analysis can be of value), and proper filter maintenance will provide your best
assurance of satisfactory oil performance.
Diesel engine lubricant recommendations are based on general experience with current lubricants of various types and
give consideration to the commercial lubricants presently available.
Diesel engines have given optimum performance and experienced the longest service life with the MIL-L-2104C, SAE 30
oils. MIL-L-2104C oils have superseded the older MIL-L-2104B and Supplement 1 oils. MI L-L-z104C, SAE 30 oils should
be used during run-in prior to initial oil drain and are recommended for continued use thereafter. Contact a reliable oil
supplier and obtain his assurance that his product has been tested and given good performance in diesel engines. An
SAE 30 oil of MIL-L-2104C performance level is recommended for year-round use. The use of
(1)Military and engine manufacturers lubricant specifications are subject to change and equipment users should keep
Informed of the latest recommendations.