SO.......1st and foremost I need to speak up and own my mistake. Yes Pennzoil ultimate Platinum 0W-40 is Dexos approved, BUT not the specific formula I have currently.
My apologies @Byrds8.
So after some specific research in which most of my info came from the Lake the motor oil geek.
The...
Sorry @Byrds8 . That's incorrect information.
It is approved by GM.
They would have to prove it was the oil changes every 2500-3 K that blew the engine. I've got every receipt for everything I've ever done to my truck. I do my best to always use products that exceed GM's quality expectations!