TRUCK SERVICE MANUAL
ENGINE
Viscosity Recommendations
The use of quality lubricating oil, combined with
appropriate oil drain and filter change intervals, is an
1. Multigraded lubricating oils may be used in
important factor in extending engine life. Cummins
applications with wide variations in ambient temperatures
Engine Company, Inc. does not recommend any specific
if they meet the appropriate performance specifications
brand of lubricating oil. The responsibility for meeting
and ash content limits shown in Table 181. Multigraded
the specifications, quality and performance of lubricating
oils are generally produced by adding viscosity index
oils must necessarily rest with the oil supplier.
improve additives to a low viscosity base stock to retard
thinning effects at operating temperatures. Poor quality
multigraded oils use a
Oil Performance Specifications
The majority of lubricating oils marketed in North
Table 18-1: Oil Recommendations
America (and many oils marketed worldwide) are
designed to meet oil performance specifications which
have been established by the U.S. Department of
Defense and the Automobile Manufacturers Association.
A booklet entitled "Lubricating Oils for Heavy Duty
Automotive and Industrial Engines" listing commercially
available brand name lubricants and the performance
classification for which they are designed, is available
from Engine Manufacturing Association, 111 East
Wacker Drive, Chicago, Illinois 60601.
Following are brief descriptions of the specifications most
commonly used for commercial lubricating oils.
API classification CC is the current American Petroleum
Institute classification for lubricating oils for heavy duty
gasoline and diesel service. Lubricating oils meeting this
specification are designed to protect the engine from
sludge deposits and rusting (aggravated by stop and go
operation) and to provide protection from high
temperature operation, ring sticking and piston deposits.
API classification CD is the current American Petroleum
Institude classification for severe duty lubricating oils to
be used in highly rated diesel engines operating with high
loads. Lubricating oils which meet this specification have
a high detergent content and will provide added
protection against piston deposits and ring sticking
during high temperature operation.
API classification SC, SD and SE were established for
the Automobile Manufacturers Association. They require
a sequence of tests for approval.
The primary
advantage of lubricating oils in these categories is low
temperature operation protection against sludge, rust,
combustion chamber deposits and bearing corrosion.
The test procedure for these specifications are published
by the American Society for Testing and Materials as
STP315.
Break-In Oils
Special "BreakIn" lubricating oils are not recommended
for new or rebuilt Cummins Engines. Use the same
lubricating oil as will be used for the normal engine
operation.
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