"For 2500/3500 Trucks with a 5.7L engine operating under a gross combined weight rating of 14,000 lb or greater, SAE 5W30 engine oil is recommended for all operating temperatures."
Thats out of my 2010 manual. The wording is a bit ambiguous. It depends on whether you take "operating under" or "rating" as the operative word.
With the word "rating" removed it would be 5W20 unless loaded to 14,000 lb. With the word rating I take it to mean if the engine is installed in a truck with a GCWR of 14,000 lb or more you would use 5W30. However if that was the intention then they could have made it much clearer using "with" instead of "operating under".
Two reasons why I am using my Summer/Winter Plan.....
1. 20wt in the winter for better cold flow. (considering M1 0w20 or PP 0w20)
2. Nearly all my towing will be in the summer months, hence 30wt. (PP 5w30)
My truck is two weeks old. At the 750 mile mark, I dumped the factory fill and poured in yellow bottle, 5w30.....and I will run that until April 1st.
I suppose if I were to ponder the intent of Chrysler around this messaging, I would guess that we are to run a 20wt, unless towing heavily.
Here's my 2500 Hemi