oil pressure and different weight oils

Ya gotta watch using just Rotella these days. The past few yrs. they've been cutting back on the ZDDP package in it because so many diesels have went to roller lifters they don't need it, or so I've read. If your lucky enough to be running a roller cam you can run just about anything.

15-40 Rotella T (triple protection) has 1200 ppm of zinc.
As far as I know and have read, none of the other Rotella's do.