I just received my answer direct from shell. Here is what I was told.
Case No: 00116431
Enquiry: Rotella t
Response:
Hello,
Trust you are well. We have not reduced the zinc content of our Rotella Oils -all of the Rotella Multigrade oils (with the exception of Rotella Multi-vehicle 5W-30) still contains approximately 1200 ppm of zinc and 1100 ppm of phosphorus which is suitable for flat tappet engine application especially those that require high zinc oil.
Hope this helps. Stay safe
This is why I run Shell Rotella T6 syn 5W40 in my wet clutch motorcycles that have shim-bucket slider cams. Its JASO-MA2 rating is good for most water cooled bikes. The 15W40 is good for most Air cooled bikes.
Stolen from BITOG, a member on here posted it there.
