Since this also goes back to the original question posted.
From Shell's Rotella T 5W-40 data sheet 2008 we can see that oil met both API Diesel and Gasoline engine specifications
and same for Rotella T-6 circa 2012
Here's someone's used oil analysis from 2012 (posted the web)
And here's the results from the last oil analysis I had done on the Jeep's original engine.
I was using 5W-40 because it got winter use and short trips, yet it consumed 30 at a faster rate. That engine was very worn out.
With respect to latest API Diesel specifications CK-4, the latest version of Widman's paper has the following
and that Rotella T 15W-40 was, as of the time he last checked, still permitted to have up to 1200 ppm since its API CJ-I.
It also still met gasoline engine API: SM