I'm about to have an oil & oil filter change on my car.
I've bought both the oil (a vollsynthetisch 5W-40 from a German firm) and the oil filter (the OEM genuine part, made in Germany too). Out of curiosity, i opened the oil filter package and noticed that the OEM filter lacks the anti drain back valve. There's just a hole and nothing else.
I have an aftermarket filter in my possession and this one comes with a plastic ADBV instead.
Another aftermarket filter from a different brand (Mahle OX173D, if you want to look at it) features an even more advanced looking metal valve.
Is there any real difference between these filters? Is the ADBV really beneficial to engine wear (the bypass valve should allow oil flow to the engine even at its thickest, but i don't know how an ADBV can improve wear protection)? My mechanic, who i task with the oil changes, says that the genuine one is the best. It's also the cheapest one, probably due to the missing ADBV.
Here's a pic of both filters (the genuine one is on the left, the aftermarket one is on the right)