1975 Chrysler Service Manual Recomendations
Oil Viscosity Recommendations
Where temperatures are consistently above +32°F
- SAE 10W-30
- SAE 10W-40
- SAE 10W-50
- SAE 20W-40
- SAE 20W-50
Suitable for year-long operation in many parts of the USA; may be used where temperatures occasionally drop as low as -10°F
- SAE 5W-40
- SAE 10W-30
- SAE 10W-40
- SAE 10W-50
Recommended where minimum temperatures are consistently below +10°F
- SAE 5W-20
- SAE 5W-30
- SAE 5W-40
Single Grades
- SAE 30 - Where temperatures are consistently above +32°F
- SAE 10W - Where temperatures range between +32°F and -10°F
When outside temperatures are consistently below 32°F, SAE 10W-30 or SAE 10W-40 are recommended for ease in cold starting. As stated in the above table, oils of the SAE 5W-20 grade number may be used when minimum temperatures consistently fall below +10°F. However, even in cold weather, these grades should not be used if the vehicle is driven in competition or other forms of maximum performance operation.
Vehicles Equipped With High Performance V-8 Engines
If the vehicle is to be used for maximum performance service (very high speed or very rapid acceleration), the engine requires heavier than normal lubricating oil. This is due to the high speeds, loads, and temperature of the moving parts developed in these engines during this type of operation.
For best protection of engine under these conditions, the heaviest oil of SE quality should be used that will permit satisfactory cold starting. SAE 30 and SAE 40 are recommended. Multi-viscosity oils SAE 20W-40 and SAE 20W-50 may also be used.