This issue has been covered extensively on BITOG and other sites.Personally, I highly doubt Shell have been packaging CK-4 in CJ-4 bottles. That could create a law suit if something happened anyone's engine and it was due to this false labeling/advertising. Plastics can be recycled very easily now days, so, why would Shell risk a law suit? Think this is merely a myth following about the internet.
Why not call Shell and ask them?
Have a Technical Question about a Shell Lubricant Product?
Shells info page on CK-4
What is PC-11? Now Called CK-4 & FA-4 | Shell ROTELLA®
There is no risk of a successful lawsuit since this CK-4 is considered a superior product and it DOES meet all the requirements of the API CJ-4 rating.
The only issues with false labeling are when an inferior product is packaged to indicate it has features it does not. For instance, if the CK-4 were not backward compatible (but it is) or if they had placed CI-4 in a jug labeled CJ-4.
Here is a deal for you. I will bet you the cost of an Oil Analysis that the new design gallon jugs labeled CJ-4 actually have CK-4 in them :winking: