Rotella 15w40

Actually it has a bad reputation because as I said, it is literally liquid plastic in a can. Using it changed the formulation of the oil by a wide margin.

I pay for a quality oil, not something I have to add a supplement to, not knowing what it does to the host oil without testing it.
In that case, you SURE wouldn't like the concoction I've got in my 440 at the moment, LOL.