Read John Martin's Member 2 Member article in TDR issue #54. It starts on page 10. He did a great job of describing why we should keep running the CI-4+ oils as along as we can in our pre-Diesel Particulate Filter trucks. The way I understand it is that they reduced the detergents and additive packages in CJ-4 to reduce the Ash residue so it won't plug the particulate filter. The CJ-4 oils won't suspend or carry the soot like the older CI-4+ or CG-4 oils, which is why some manufactures are saying you might have to lower your oil change intervals when using the CJ-4 in the older diesels. Also read TDR issue #51 "new lube oils" on page 57. If you have a Jan. 07 any brand diesel with a particulate filter you have to run the CJ-4 oil.
Regards, Mike.