Dodge 2004 Ram 2500 Owner's Manual page 326

326 MAINTAINING YOUR VEHICLE
Checking the vehicle while it's on level ground will also
improve the accuracy of the oil level readings. Add oil
only when the level on the dipstick is below the "ADD"
mark. The total capacity from the low mark to the high
mark is 2 quarts (1.9 liters).
Never operate the engine with oil level below the "ADD"
mark or above the upper "SAFE" mark.
Change Engine Oil
CAUTION!
Overfilling or underfilling the crankcase will cause
oil aeration or loss of oil pressure. This could dam-
age your engine.
Road conditions as well as your kind of driving affect the
interval at which your oil should be changed. Check the
following to determine if any apply to you:
• Frequent short trips where the engine does not achieve
full operating temperature (operating temperature de-
fined as 190° F (66° C ) coolant temperature).
• Extensive engine idling (over 10 minutes per hour of
operation) at ambient temperatures less than 32° F (0°
C).