Yeah as I understand it, the new emissions devices are extremely finicky. Medium and especially high SAPS oils are not healthy for the particulate filter and catalyst. They are wanting to make sure that the oil used in the new engine will not cause issues with the emissions equipment, so they are specifying "European" oils that are designed and created to be used in engines with direct injection, particulate filters, turbos, etc. Most of the oils that meet FCA MS-12991 are labeled as "gas and diesel" on the bottles.
Having said that, I would like for
@RamCares to get us an explanation from the engineering team also about why we can't use diesel-specific oil like Rotella T6 anymore.