Dodge 2009 Dodge Ram Pickup 2500 - Manual (Page 90)

Oils with a high ash content may produce deposits on
valves that can progress to guttering and valve burning.
A maximum sulfated ash content of 1.00 mass % is
recommended for all oil used in the engine.
The same oil change interval is to be followed for
synthetic oil as for petroleum based oil. Also, synthetic oil
must meet the same performance specifications as petro-
leum oil.
Engine Oil Viscosity (SAE Grade)
Use SAE 15W-40 engine oil that meets Chrysler Materials
Standard MS-10902 and the API CJ-4 engine oil category.
In ambient temperatures below 0°F (-18°C), SAE 5W-40
synthetic
engine oil that meets Chrysler Materials Stan-
dard MS-10902 and the API CJ-4 engine oil category is
required.
CAUTION!
Failure to use SAE 5W-40 synthetic engine oil in
ambient temperatures below 0°F (-18°C) could result
in severe engine damage.
88 MAINTAINING YOUR VEHICLE