Theres a post on tacomaworld where hey cut the oil filters open fram has cardboard in it and a paper filter some of oil filters have some cheap parts in it.
I recently swapped from the mobil1 to K&N oil filter the last couple oil changes. One thing I noticed is the k&n made my oil change color to a dark brown faster than using mobil1 filter. About 500 miles...Curious whether that's good or bad:dontknow: