Pontiac 1953 Owner's Manual page 41

SELECTING OIL OF THE PROPER NUMBER-A grade of oil
should be used which provides safe lubrication, satisfactory oil econ-
omy under warm climatic conditions, and easy starting at the lowest
atmospheric temperatures expected during the- period the oil is to
remain in the engine.
Based on these considerations, the S.A.E. grades of engine oil which
are recommended for your Pontiac engine under various climatic
conditions are as follows:
Atmospheric Temperatures
Expected
31°F. to HOoF.
to°F. to HO°F.
tOoF. below zero to 9SoF. above zero
to°F. below zero and colder
S.A.E.
Grade Recommended
20
20W
tOW
5 W (see Note)
NOTE: S.A.E. 5 W oils which are identified as "For Service MS" are
recommended. These oils provide easy
startin~
characteristics at low
temperature
alon~
with the
operatin~
temperature characteristics
of
~ood
quality 10
W
oils.
OIL CHANGE RECOMMENDATIONS-Engine oil should be
changed whenever it becomes contaminated. Contamination is usually
due to the accumulation of water, dust or dirt, or the breakdown
products of the oil and fuel.
It is always
advisable to drain the crankcase only after the engine is
thoroughly warmed. The benefit of draining is lost, to a large extent,
if the crankcase is drained when the engine is cold as the oil will be
thick and will not drain thoroughly.
First 1,000 Miles-During the first 1,000 miles, use the oil in the
crankcase as received from the dealer. (Special "break-in" oils are
unnecessary. They should not be used under any circumstances unless
the manufacturer can furnish satisfactory proof that the compound
contains no harmful substances.) At the end of the first 1,000 miles,
the crankcase should be drained and refilled to the proper level with
an oil suitable for your individual climatic and driving conditions.
Should it be necessary to add or change engine oil during the first
- 1,000 miles, an oil not heavier than 10 W should be used.
Average Driving-For average driving conditions, an oil change is
recommended every 3,000 to 4,000 miles. This applies to all owners
with the exception of those driving under the conditions described in
the following paragraphs.
Driving in Dust-When the car is generally operated in dusty terri-
tory, consideration should be given to more frequent oil changes.
138
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