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)

enter image description here

  • 1
    Are you sure that is a by-pass valve? Is it not just a none return valve(anti drain back)?
    – HandyHowie
    Aug 29, 2018 at 12:21
  • @HandyHowie Yes, it definitely looks like an ADBV. Thank you very much!
    – Al_
    Aug 29, 2018 at 12:48
  • 1
    Deleted my answer as you have changed the question to something completely different.
    – Solar Mike
    Aug 29, 2018 at 13:10

1 Answer 1


That looks more like an anti drain back valve. It is just there to stop the oil filter emptying when the engine is turned off.

Is the filter mounted with that valve at the bottom?

Since you say that this is mounted with the valve to the top, then I would say that the valve is unnecessary. Maybe this filter can fit into other engines where it is installed the other way up, in that orientation, the valve would be functional.

  • Hmmm, i think you're right. A relief valve should have a spring and the one on the aftermarket filter is basically a plastic valve that just floats around and shows absolutely no resistance to touch. I guess the actual bypass is integrated in the filter housing. The filter housing is mounted at something like a 60° angle (from vertical) and the filter fits inside the housing with the anti drain back valve on the top. I'll reword the question. Thanks for noticing.
    – Al_
    Aug 29, 2018 at 12:45
  • 1
    I have updated my answer.
    – HandyHowie
    Aug 29, 2018 at 12:51
  • If i fit an ADBV equipped oil filter, other than being unnecessary, could it also possibly be detrimental (as an example: impair oil flow)?
    – Al_
    Aug 29, 2018 at 12:56
  • 1
    I can't imagine why it would cause a problem. Presumably the opening where the oil flows through is a similar diameter in both examples?
    – HandyHowie
    Aug 29, 2018 at 13:00
  • 2
    It's probably cheaper for the aftermarket manufacturer to minimize the number of different filters and get better economies of scale, rather than bothering about spending 5 cents on an unnecessary bit of plastic for a small number of engine types.
    – alephzero
    Aug 29, 2018 at 20:13

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