I copied this from the NCRS forum.
Q - I heard shell rotella changed again and lowered zddp to less than 800.
Dukes answer - Okay, the CJ-4 spec has been in place since 2006, and the first released products showed up on retail shelves in early 2007, and the 1200 PPM P limit will not change. Any major changes such as a reduction in P will require a new spec, and I am not aware that a new spec is anything other than in the advanced planning stage at this point with industry providing input. I expect the CJ-4 spec to remain current and not be superseded for several more years, and when a new spec is released sometime in the future, we will know if there is a change to the CJ-4 P limit.
The Internet is full of ignorant morons that run around spreading baseless rumors - Chicken Littles screaming that the sky is falling.
My suggestion is that anyone who "hears" something bad do some research. Detailed information on engine oils is readily available from the API and manufacturers, and the Chevron Delo Web site provides the most comprehensive technical data. Any other manufacturer's same API category product is going to be essentially the same because they are all blended to meet the same performance specifications/requirements including the same comprehensive test suite that all must pass.
So the next time anyone "hears" something about motor
oil, how about doing some research on your own before you pass along Internet trash on this site.
Until a new C-category spec is released by API in the indeterminate future, the CJ-4 product will remain the same as it is today, which is the same as it was when CJ-4 products showed up on retail shelves in early 2007. The P concentration will not change!
Likewise, the engine
oil information in the article published in The Corvette Restorer a year ago will remain current until a new C-category spec is released, and when a new spec is finalized, I'll likely know about it, including any changes that might affect engine
oil choice for our vintage cars.
Until then keep using CJ-4 or CI-4 and ignore all the scare-mongering on the Internet!