I guess back in the day Pennzoil and Quaker State were refined from Pennsylvania crude oil which contained quite a bit of paraffin.
I'm sure that it did sludge up engines, back in the day, if not changed at much shorter OCI's. There were lots of oils sludged up engines back then caused by more than just motor oils. Head gasket issue, poor PCV systems and oils that were not up to the test of today's standards.
However, Pennzoil and QS were sold off and now SOPUS owns the Pennzoil and Quaker State names. SOPUS, to the best of my knowledge, does not use PA crude oil in their motor oils.
All the oils made by SOPUS are out of the Houston, TX area and not out of PA.
There are only a couple of isolated oils now made in PA and think some of these are racing oils.