I'm getting my engine together and thought I would get some oil, the oil was cheaper with a stp filter so I took the combo.
This is on my 2.3 turbo engine and I've ran nothing but wix filters, I pulled the STP filter out of the box and just laughed.
I'll admit its a pita to take wix oil filters off because they sit so close to the steering shaft but I guess its worth it.
Here's a pic of the stp and a wix filter that has been sitting out for a while.
(http://i245.photobucket.com/albums/gg74/nukkah617/T-Bird/IMAG0829_zpsz7nyoscj.jpg) (http://s245.photobucket.com/user/nukkah617/media/T-Bird/IMAG0829_zpsz7nyoscj.jpg.html)