The manual for my truck (2007 - 5.9), calls out an oil spec. of API CI-4. When I was looking at oil this weekend, I noticed the Rotella 15-40 calls out CI-4 Plus but not CI-4. The other oils I looked at that called out CI-4 Plus, also hadthe CI-4 designation. I have not had much luck finding the difference. Does anyone know? Does CI-4 Plus cover all of the requirements of CI-4? I just want to make sure, for warranty's sake.

 

I did a quick Google search and came up with this interesting article. I especially liked the attachment article. Nicely done. Good to know information.

http://www.turbodieselregister.com/a...lem/Page1.html

 

The newer ratings (CI-4+ and CJ-4) are always backwards compatible, so if your manual calls for CI-4 it's okay to use CI-4+ or CJ-4. It works the same way for gas engines; an older car may call for an oil rated SJ, so it's okay to use SM or whatever the current rating is.

You may want to stick with CI-4 or CI-4+ instead of CJ-4, since they seem to have a higher TBN rating which should give them a longer life.

Here's another link you can read: http://www.apicj-4.org/faqs.html

 

Good luck finding a steady supply of CI-4 and CI-4 plus.