I've been using the Royal Purple 5W-40 and having HHP change my oil. My dealer hasn't done anything to my car except TSB work and a front-end alignment.
Jason. Will this get your panties untwisted? The SRT Engineers said the new Mobile-1 0W-40 formulation is fine. http://www.challengertalk.com/forums/28459-post120.html
I didn't want to say anything as to not upset Jason but ... I got a call back from my service advisor the other day who checked with the "higher ups" at Chry and they all say the Mobil 0-40 is fine. Sooooooo ...