N-Trouble wrote:
The whole thing just sounds a little weird to me. At the end of the day the 6.4 is still an internal combustion gas engine. There is nothing exotic about it. Have never heard good things about Penzoil in general and would never buy a vehicle that could only use oil from a single source. Especially a work truck. Exotic sports car maybe... I would just run any of the top synthetics out there (Amsoil, Mobil1, Rotella) and not even think twice about it.
While I agree it's likely a marketing racket between RAM and Penzzoil (like the previous recommendation to only use Mobil 1 in the SRT cars), it has been said that the wrong viscosity oil will cause a check engine light due to the MDS system using oil to activate/deactivate the MDS system.