I recently had he oil changed in my 2008 D3500 Cummins at one of the local Dodge dealerships.
I was told they had nothing but synthetic oils.
Getting hard to find conventional oil in parts stores, unless you buy the house brand (NAPA, Fram).
This is very true - products in general. I use Castrol Syntec 0W40 for my 2016 Challenger Scat Pack & cannot find it in any stores around me. I just ordered two jugs of it online today through Amazon. Hey - what are you gonna do? I prefer to support brick & mortar, but they ain't got!