what oil to use

This got “discussed” on another thread and the ZDDP issue seems to be important.
http://www.forabodiesonly.com/mopar/showthread.php?t=27306&page=4

I’m going to research the content in the synthetic brands.
(As much as possible since this is all must be top-secret stuff):dontknow:
I see that Mobil 1 has Turbo Diesel Truck 5W-40, CE, CF-4 CG-4, CH-4 or CI-4