See Figures 1 and 2OIL
Chrysler Corporation recommends the use of a high quality, heavy duty detergent oil with the proper viscosity for prevailing conditions. Oils labeled SG/CC are satisfactory for use in all engines; however, a higher quality oil, labeled SG/CD is preferred.
Oil must also meet viscosity standards. Follow the chart below precisely. Make sure the oil you buy is clearly labeled so as to confirm to both these basic standards.
Use only quality oils. Never use straight mineral or non-detergent oils, that is, oils not equipped with special cleaning agents. You must not only choose the grade of oil, but the viscosity number. Viscosity refers to the thickness of the oil. It's actually measured by how rapidly it flows though a hole of calibrated size. Thicker oil flows more slowly and has higher viscosity numbers-SAE 40 or 50. Thinner oil flows more easily and has lower numbers-SAE 10 or 20.
Chrysler recommends the use of what are called "multigrade'' oils. These are specially formulated to change their viscosity with a change in temperature, unlike straight grade oils. The oils are designated by the use of two numbers, the first referring to the thickness of the oil, relative to straight mineral oils, at a low temperature such as 0°F (-18°C). The second number refers to the thickness, also relative to straight mineral oils, at high temperatures typical of highway driving (200°F (93°C)). These numbers are preceded by the designation "SAE,'' representing the Society of Automotive Engineers which sets the viscosity standards. For example, use of an SAE 10W-40 oil would give nearly ideal engine operation under almost all operating conditions. The oil would be as thin as a straight 10 weight oil at cold cranking temperatures, and as thick as a straight 40 weight oil at hot running conditions.