Is the STP oil filter for my 2005 6.0 any good? Where is the best place to get filters?

 

The Fram filter for the 6.0 is exactly the same as Motorcraft... Just re-packaged! If you have a Pep Boys nearby go there and pay only $3.50 each with a limit of 4 (instead of $20 each) although you might need the coupon from your local Sunday newspaper.
See the details in the link below:

https://www.ford-trucks.com/forums/6...l-filters.html

 

Or you can print the coupon from the Pepboys website here: http://pepboys.shoplocal.com/pepboys...PepBoys-071007