Purolator used for approx. 3000 miles / 3 months with Supertech 10w30 in a 95 Geo Prizm with 128K miles on the car. Filter was good and no tears Delco PF52 used for approx. 2000 miles / 2.5 months with Smittys syn blend 10w30 in a 4.3L v6 S10 pick up that I replaced the intake manifold gasket on. There was a some sludge under the valve covers so I am doing low mile OCIs for now. I have no problems using the Purolator classic and I prefer AC delco oil filters.