I noticed that all varieties of QS claim to have at least some seal conditioners to "help prevent and reduce leaks." But the star chart on the Pennzoil only claims the high mileage helps this issues. I know the wording is different, "prevent and reduce leaks" vs "conditions older seals." Still, I found it interesting that QSUD claims to help reduce leaks.
So, what you folks think? Could QS in general have boosted seal conditioners compared to PP varieties?
So, what you folks think? Could QS in general have boosted seal conditioners compared to PP varieties?