Just my 2 cents, but when it comes to filters, only motorcraft for me. Aftermarket filters were responsible for part of the undeserved bad rep the 6.0 has. More than a few of the aftermarket oil filters were not made to spec and failed, killing the engine. WIX may be good, but I'll spend a couple extra bucks to protect the 15K engine. Ford actually put out a warning video (I think you can see it on youtube), warning 6.0 owners about aftermarket filters. The 6.0's lifeblood is oil, and I don't mess around in that area - too much risk, for too little reward.