Is it possible that the filter could have been overtightened, damaging the gasket in the process? Not intending to be critical of your work, just that I hand-tighten only and have never used a filter wrench. So IDK if it might be possible to do something like push the gasket out of shape leaning too hard on a wrench.Don't really know why, but after a few thousand miles there would always be a few drips on the bottom of the filter, only one that ever gave me any trouble. Might have something to do with the stamping. Also, the oil filter wrench wouldn't fit on properly, again, inconsistencies in the metal stamping.