Review on Mobil 1 Extended Performance Oil Filter - M1-110/M1-110A by Eric Ross

This filter has louvers through which the oil must flow after it has passed the filter element. Blinds are probably used because they are cheaper to manufacture than openings. The problem is that many of the filters I've tested at retail, after seeing my lovers partially open, have either unopened holes or holes that look like hair. So when this happens it's much more likely that the filter is in the bypass and not the oil filter! Use FRAM XG instead of that overpriced Mobil1.