Specifications

Engine Oil Recommendations
Your use of the proper Engine Oil is of great importance in obtaining
maximum performance and satisfaction from your car.
Oil oxidizes when heated. Unless protected against oxidation, crank-
case oils may form sludge and varnish, and under some conditions,
corrosive acids.
To minimize the formation of these harmful decomposition products
and to supply the type of oil best suited for the different operating
conditions, the refiners market several types of oils. The particular
types recommended for passenger car use have been defined by the
General Committee, Division of Marketing, American Petroleum
Institute, as follows:
3 "Regular Motor OH—This term shall be used to designate a
straight mineral oil. Oils of this type are generally suitable for use in
internal combustion engines under moderate operating conditions."
O "Premium Motor Oil—This term shall be used to designate oils
having proved oxidation stability and bearing corrosion preventive
properties. Oils of this type are generally suitable for use in internal
combustion engines where operating conditions are such that regular
oils do not give satisfactory service."
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> "Heavy- Duty Motor Oil —This term shall designate an oil having
proved oxidation stability, bearing corrosion preventive properties
and detergent-dispersant characteristics. Oils of this type are gener-
ally suitable for use in both high speed Diesel and gasoline engines
under heavy-duty service conditions."
The Regular or straight mineral motor oils are satisfactory for
use in average passenger car service under normal driving conditions.
These are considered to he a combination of low and medium speed
driving with only an occasional long run at high speed.
Under more severe driving conditions where the engine is required
to develop more nearly full power for a much larger percentage of
the time, as for example in mountain climbing and in sustained high
speed driving, the PREMIUM MOTOR OILS are recommended.
The heavy-duty oils which are recommended for use in heavy-duty
truck, bus, Diesel, and gasoline engines are equally satisfactory for
use in passenger car engines under the same operating conditions for
which the PREMIUM MOTOR OILS are recommended.
FOR MAXIMUM PROTECTION OF YOUR CADILLAC EN-
GINE UNDER ALL DRIVING CONDITIONS, IT IS RECOM-
MENDED THAT PREMIUM OR HEAVY-DUTY GRADE
MOTOR OIL BE USED.
For the first 1,000 miles, use the oil in the crankcase at the time your
car was delivered to you. During this period should additional oil
be necessary, use nothing heavier than 10-W oil in winter or 20-W
oil in summer. Change oil at 1,000 miles. Break-in oils or compounds
are entirely unnecessary. Do not use them under any circumstances.
> After the First 1,000 Miles
For better all-around engine performance after the first 1,000 miles,
SAE 20-W or SAE 20 engine oil should be used during summer
weather. If your car is regularly driven at high speed, or if the prevail-
ing daylight temperature averages 90° F, SAE 30 oil may be used.
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