Fuel, Oil and Coolant Specifications
DETROIT DIESEL LUBRICATING OIL SPECIFICATIONS
drain recommendations (based on used oil sample
GENERAL CONSIDERATIONS
analysis and experience) and proper filter maintenance,
All diesel engines require heavy-duty lubricating oils.
will provide the best assurance of satisfactory oil
Basic requirements of such oils are:
performance.
Lubricating Quality
Detroit Diesel Allison lubricant recommendations are
based on general experience with current lubricants of
High Heat Resistance
various types and give consideration to the commer-
Control of Contaminants
cial lubricants presently available.
LUBRICATING QUALITY. The reduction of friction
RECOMMENDATION
and wear by maintaining an oil film between moving
parts is the primary requisite of a lubricant. Film
Detroit Diesel engines have given optimum perfor-
thickness and its ability to prevent metal-to-metal
mance and experienced the longest service life with the
contact of moving parts is related to oil viscosity. The
following oil performance levels having the ash and
optimums for Detroit Diesel engines are SAE 40 or 30
zinc limits shown:
weight.
HIGH HEAT RESISTANCE. Temperature is the most
important factor in determining the rate at which
deterioration or oxidation of the lubricating oil will
occur. The oil should have adequate thermal stability
*Military Specification MIL-L-2104B is obsolete and
at elevated temperatures, thereby precluding forma-
new developed products can no longer be qualified
tion of harmful carbonaceous and or ash deposits.
to meet this performance level. However, many
CONTROL OF CONTAMINANTS. The piston and
lubricants formulated to meet the performance
compression rings must ride on a film of oil to minimize
criteria of MIL-L-2104B/1964MS are still being
wear and prevent cylinder seizure. At normal rates of
m a r k e t e d . Detroit Diesel engines have given
consumption, oil reaches a temperature zone at the
optimum performance and experienced the longest
upper part of the piston where rapid oxidatation and
service life using MIL-L-2104B/1964MS lubricants.
carbonization can occur. In addition, as oil circulates
The majority of MIL-L-2104B/1964MS lubricants
through the engine, it is continuously contaminated by
have a sulfated ash content between 0.55 and 0.85
soot, acids, and water originating from combustion.
percent by weight.
Until they are exhausted, detergent and dispersant
**Supplement 1 oils have a history of very satisfactory
additives and in keeping sludge and varnish from
performance in Detroit Diesel engines. Supplement
depositing on engine parts. But such additives in
1 oils have a relatively low ash content. However.
excessive quantities can result in detrimental ash
the Supplement 1 oil specification is obsolete and
deposits. If abnormal amounts of insoluble deposits
new products cannot be qualified to meet this per-
form, particularly on the piston in the compression
formance level. Some older formulations are still
ring area, early engine failure may result.
distributed and used by Detroit Diesel engine
customers.
Oil that is carried up the cylinder liner wall is normally
consumed during engine operation. The oil and addi-
l SAE 40 grade oil has performed satisfactorily and is
tives leave carbonaceous and or ash deposits when
recommended in Detroit Diesel engines. Obviously,
subjected to the elevated temperatures of the com-
the expected ambient temperatures and engine
bustion chamber. The amount of deposits is influenced
cranking capability must he considered by the
by the oil composition, additive content, engine tem-
engine owner/operator when selecting the proper
perature, and oil consumption rate.
grade of oil. Only when the ambient temperatures
and engine cranking capabilities result in difficult
starting should SAE 30 grade oil be used.
DETROIT DIESEL LUBRICATING
OIL SPECIFICATIONS
ASH LIMIT
The sulfated ash (ASTM D-874) limit of all the lubri-
OIL QUALITY
cants recommended or selected as alternates for use
in Detroit Diesel engines shall not exceed 1.000 per-
OIL QUALITY is the responsibility of the oil supplier.
cent by weight, except lubricants that contain only
(The term oil supplier is applicable to refiners. blend-
barium detergent-dispersant salts where 1.500 percent
ers. and rebranders of petroleum products. and does
by weight is allowed. Lubricants having a sulfated ash
not include distributors of such products.)
content between 0.55 and 0.85 percent by weight have
a history of excellent performance in Detroit Diesel
There are hundreds of commercial crankcase oils mar-
engines. Lubricants having a sulfated ash content
keted today. Obviously. engine manufacturers or users
greater than 0.85 percent by weight are prone to
cannot completely evaluate the numerous commercial
produce greater deposit levels in the ring belt and
oils. The selection of a suitable lubricant in consulta-
exhaust valve areas of the engine.
tion with a reliable oil suppler, observance of his oil
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