Which Oil?

I use Rotella T. It's about $10 a gallon. A lot of guys hear use the synthetic stuff. I know that Amsoil is really popular, and I'm sure it's great. However with the dpf and egr dumping fuel that does in fact get into the crankcase, I don't think the longer miles between oil changes that synthetics promote is a wise decision for your engine. 5000 mile changes seem to be a better coarse of action, and synthetic is too expensive for that rate of change. Just my opinion for this particular engine/emission configuration. If you remove your dpf and thereby stop the regen cycles, this problem of fuel in your oil goes away.

Grey

CJ-4 oil is very easy to obtain nowadays.

I have been happy so far with my bypass setup and the Amsoil, though i do have to agree with grey a little that you may not get as much for extended intervals with the contamination of the EGR/DPF

Hey Travis13 I will check on this for you on Monday and let you know

- ROTELLA Products

I guess this stuff is fine. My local Napa carries this oil and an oil filter

on the 6.7's the egr is the main cause for the oil getting dirtier faster. if you ran a bypass oil filtering setup it seems you would be able to safely extend your oil change interval