2 equivs. each w/ diff. bypass specs.

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dlundblad

dlundblad

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How does this work?

The OEM Mann filter for the Audi A4 3.0 V6 has a bypass spec of about 33 psi as does the WIX and Fram equivalents. The spec'd filter by Mobil 1 for this engine is the M1-204 (PH16 equiv.) and has a bypass of about 12 psi. That is 3x less than the OEM bypass spec.

How does this work? As far as I can tell, this is the only filter spec'd for this engine with such a low bypass. If the M1-204 was being ran, wouldn't it always be in bypass?
 
Bypass only happens if filter gets clogged and is there to protect the filter itself...has nothing to do with the oil pressure you see on your gauge...there is way more to it than that but thats the short answer.
 
The bypass operates as a relief for pressure differential between the clean and dirty sides of the media. It's not based on engine oil pressure. Your oil pressure can be 100 psi, and the filter can stay in normal (non bypass) operation. Each filter has it's own tolerance for pressure differential.
 
Had the same issue when I bought some K&N oil filters for my Forester XT and then found later that they didn't meet Subaru's spec for bpyass pressure. I freaked out and bought OEM filters after my first change...now that I better understand the purpose of the bypass valve in the filter, I'm not worried about using the K&N I still have sitting around for a future change. I doubt very much that my filters will get dirty enough for the valve to be much of a factor, anyway.
EDIT - probably a bigger concern about the K&N filter I did use was an apparent tiny leak from below the 1" nut on top...it was just a trace, but it definitely wasn't there when I first put it on and I felt obligated to check it often. Never developed into a real problem.
 
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Flat gasket filters seem to weep a tad on subies - Ive had 8 of 'em ... Subies that is.
That drip at the nut prob came from the top side (base).

Ive had weeping with the famous Wix 51356 on a Fos X EJ253 and had to discontinue use.
 
Originally Posted By: ARCOgraphite
Flat gasket filters seem to weep a tad on subies - Ive had 8 of 'em ... Subies that is.
That drip at the nut prob came from the top side (base).

Ive had weeping with the famous Wix 51356 on a Fos X EJ253 and had to discontinue use.


My filter sits "nut up" on top of my engine (2.0l turbo), so I suspect the weep must have come from the joint for the nut...I found a few complaints online about other K&N filters with the nut doing much worse! If I ever buy any more K&Ns, I'll go "nutless" because the position of the filter makes it fine for hand tightening, anyway (and they're cheaper without the nut).
 
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Originally Posted By: JRed
If anything is going to kill an Audi it won't be an oil filter.


Hah. I'm surprised something with such a high sticker price has such a bad rap.
 
Where did you get the bypass specs for the Mobil 1 filter? I haven't been able to get these specifications for the Mobil 1 filters I use...
 
Originally Posted By: dlundblad
How does this work?

The OEM Mann filter for the Audi A4 3.0 V6 has a bypass spec of about 33 psi


Do you mean the Mann Branded aftermarket filters or the orginal Audi branded filters made by Mann? Those could have 2 different bypass settings? Same is true with some of the Toyota Branded filters (made by Denso), and some of the Denso first time fit aftermarket brand filters. The Toyota brand filters have a lower by pass setting, than the Denso aftermarket filters. I guess this is because some of the aftermarket filters are made to fit multiple applications.

I would actually rather have a lower by pass setting in my filters to insure proper oil flow at all times. Bypass is not just activated when the filter is completely clogged, filter could also go into bypass at start-up during very cold temps.
 
Originally Posted By: Hessam
Originally Posted By: dlundblad
How does this work?

The OEM Mann filter for the Audi A4 3.0 V6 has a bypass spec of about 33 psi


Do you mean the Mann Branded aftermarket filters or the orginal Audi branded filters made by Mann? Those could have 2 different bypass settings? Same is true with some of the Toyota Branded filters (made by Denso), and some of the Denso first time fit aftermarket brand filters. The Toyota brand filters have a lower by pass setting, than the Denso aftermarket filters. I guess this is because some of the aftermarket filters are made to fit multiple applications.

I would actually rather have a lower by pass setting in my filters to insure proper oil flow at all times. Bypass is not just activated when the filter is completely clogged, filter could also go into bypass at start-up during very cold temps.

Where did you find Denso bypass specs and that toyota is less than the first time fit?
 
There are many lengthy discussions about this same topic for Subaru filters. I believe the Subaru OEM filter bypass is like 23 psi, whereas most after market filters are closer to 8-12psi. Some people think it's very important, and some people think it's nothing. Both sides have spent a lot of time arguing their point. For my Subaru I just used high quality filters that came closer to matching the spec, so for years I used Purolator PureOne filters which had a bypass of like 18 psi, then because of the tear issues I started using Wix filters that had the 21-22psi bypass relief pressure.

You said Fram and Wix had the correct bypass pressure. I'd just use one of those. The Fram Ultra filters are amongst the best filters you can buy at most auto shops, and the Wix filters are very excellent themselves. If you can get either at a good price, just go with those and you'll be covered for the bypass pressure and have an excellent filter cleaning the oil too.
 
you can check filtertopia.com ... Baldwin used to have a great filter cross-reference site as well, but not anymore.
Fram makes the Honda OEM filters much like a their TG filters, but the aftermarket Fram TG's have different specs than the Honda branded (Frame made) ones.
Not saying that this is true for all applications, but there are some applications where the OEM branded filter does not have the same specs as their aftermarket line of filters, such as the Subie example noted above.
 
Originally Posted By: Nate1979
Bypass setting is also specific to the filter media.


So a filter with a higher bypass also has a less efficient (restrictive) media?
 
Originally Posted By: dlundblad
Originally Posted By: Nate1979
Bypass setting is also specific to the filter media.


So a filter with a higher bypass also has a less efficient (restrictive) media?


No I'm saying that the filter manufacturer must spec the bypass setting specific to the filter media based on the OEM flow requirements. It's ignorant to only look at the bypass specs (like the Subaru internet engineers do) without understanding the flow characteristics of the media.
 
More restrictive filtering media uses BPV with a higher psi rating? And the filter with lower psi BPV will have better flow?

Microguard MGL57060

Wix 57060

How can I find out flow and efficiency comparison for these 2 filters?
 
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