I bought two oil changes because my headgasket blew and im going royal purple but first want a 'guinea pig' oil change to get rid of the milkshake first... so i bought two oil filters at o'reillys.
Got a K&N oil filter to go with the royal purple, and the 'cleanser' oil change is just Penzoil, so i just grabbed a cheapo. Turns out i grabbed an STP oil filter, and when i took it out of the box I almost crapped my pants, it was amazingly similar to the k&n!! im like, seriously?! I hold them up together... sure enough.
So heres the rundown...
K&N is defiantly stronger built on the outside... has a 1" nut on the outside for EZ removal, self lubed o-ring, box states 90% efficency of particle removal... $13
STP shares exact same base as k&n filter with self lubed o-ring, but doesnt have the nut on the back for EZ removal, construction is durable but not noticeably sturdy like k&n, and box states 96% efficency!!! paid a whole $3
Ten dolla difference is why im posting this! K&N is nice and all but if STP has the same filter system under that blue-coated surface, why ever buy POS fram??
Side by side pic comparison...




^K&N

^STP



Hope someone got learn'd
