I have a '09 Ram w/ HEMI
the book reads change motor oil & filter every 3,000 miles
I changed over to synthetic quite a while ago
I go 5,000 miles between changes, mostly because 5,000 is easy to remember, but also i am on the road a lot, i could get a call at any time to drive across the USA to do a job.
There have been times that i have had a oil change in one month & had to get another one in the next month, because i was already due mileage wise.
My dealership knows me quite well
I am considering ordering a Ram 1500 Diesel Quad Cab possibly in July, i use way to much gas with the HEMI