The early version of this motor in the 4th Gen Rams did not have a very good track record. However, the engines were redesigned for the 5th Gens, and so far, seem to have much better reliability (although, it is still too early to tell for long-term reliability).
Just stick the recommended maintenance schedule. There’s a whole sub-forum for the EcoDiesel…I’d recommend taking a look in there and reading some of the threads.
Discussion for the 3.0 EcoDiesel V6 and 8 speed transmission
5thgenrams.com