Dodge Ram 1500 trucks with 3.7-, 4.7- or 5.7-liter engines need 5W-30 oil. However, the outside temperature can change the vehicle's needs to a different oil viscosity grade.
If the minimum air temperature is above 0 degrees Fahrenheit, a 10W-30 oil can be used, but the 5W-30 grade is still preferred for the truck. For temperatures that range from -20 degrees to 100 degrees Fahrenheit, 5W-30 can be used. Synthetic or semi-synthetic oils may be used, but oils with any additives are not recommended. All oil should be API certified and meet the SAE viscosity standards. Always refer to the truck's owner's manual for specific details.