Seemingly Dexos certification = confusion ...... the oil forum is going through the same probelm.
FWIW It looks like Dexos 1 gen 2 is a revised list for 2017 with 777 less entries than before. Pennzoil Ultra isnt even on the list for Sept. 2017.
Dexos 2 seems to be the same list shown as last year; the same 155 entries; not seeing a new list for 2017 posted yet.
So would you roll with what is on the list or the bottle label?
Wonder what GM Dexos opinion would be?
http://www.gmdexos.com/owner/brands/