The Mann OEM Audi filter question

[Georgi1]

I have always used the original Mann filter on my 2.8 V6 Audi and over the years it got updates. The anti drain back valve was rubber and then it is white silicon, the filter media itself was that dark brown/orange and is now very bright yellow - most likely blend media. However the design remain the same.
What is very strange for me is the ONLY 4 RATHER SMALL HOLES for oil to pass. There are another 10 different brand oil filters for my engine and none of them has such a small number and size of holes. In Germany for example the second most used best filter after OEM/Mann would be Mahle. Even their filter has double the number holes.

This is an example with the cross ref filter from Purolator. Although smaller it has double the overall holes. Even this small tiny Toyota filter has more overall holes than it.

Any thought on that?

 

[ZeeOSix]

The pressure drop across that base plate with 4 holes must still be acceptable for the engineer(s) who designed it. They just don't make a design like that without verifying the flow performance. Most people can't get a good estimate of how something like that flows oil just by looking at it ... it needs to be ran through a flow analysis.

Besides, engines use a positive displacement oil pump for a reason, to ensure it forces oil adequately through various components that have different flow resistance. The engine's oiling system is typically has 12-15 times more flow resistance than an oil filter.

 

[shortyb]

Odd if another German filter (ie; Mahle, Hengst) would be different in the same application. The design parameters are very specific among auto manufacturers and finding something as "insignificant" as an oil filter that is drastically different across suppliers would be rather unusual. For example, my 2.0T CCTA engine uses a metal can spin-on with a plastic standoff for "upside down" mounting and all of the OE "German" ones available (VAG, Mann, Mahle, Hengst) are identical except for part numbers and labeling.

 

[Chris142]

For example, my 2.0T CCTA engine uses a metal can spin-on with a plastic standoff for "upside down" mounting and all of the OE "German" ones available (VAG, Mann, Mahle, Hengst) are identical except for part numbers and labeling.

And if you use ANY other brand it will dump oil all down the front of the engine when removed.

 

[shortyb]

And if you use ANY other brand it will dump oil all down the front of the engine when removed.

Always amazed that it doesn't dribble even a drop when spun off. Yet another reason to use the OE speced "German" ones (my last Mann was made in Spain though).

 

[ZeeOSix]

Always amazed that it doesn't dribble even a drop when spun off. Yet another reason to use the OE speced "German" ones (my last Mann was made in Spain though).

Does that filter have an ADBV? If not, then the oil is draining out so there isn't anything to dribble when the filter is removed.

 

[shortyb]

Does that filter have an ADBV? If not, then the oil is draining out so there isn't anything to dribble when the filter is removed.

Yep. White silicone one. 5-hole base plate too.

 

[ZeeOSix]

Yep. White silicone one. 5-hole base plate too.

Then it probably isn't sealing very well if other oil filters with an ADBV will retain oil that comes out when the oil filter is removed. Or the oil might be draining out the center tube if the media is pretty porous.

 

[shortyb]

Then it probably isn't sealing very well if other oil filters with an ADBV will retain oil that comes out when the oil filter is removed. Or the oil might be draining out the center tube if the media is pretty porous.

Oh there is still oil in it when taken off. Just nothing comes out when you do. Likely what oil that would, has already drained from the center tube back into the engine after shutdown.

 

[Chris142]

Always amazed that it doesn't dribble even a drop when spun off. Yet another reason to use the OE speced "German" ones (my last Mann was made in Spain though).

I get ones with fram, stp etc and they make a mess

 

[skyactiv]

Once had a GTI and my wife had an A4 that used an oil filter with a stud on it. I've had a Fram and even a Mann filter leave the stud and plastic thing in the block a few times. Switched to Mahle and it never happened again.

 

[Georgi1]

Odd if another German filter (ie; Mahle, Hengst) would be different in the same application. The design parameters are very specific among auto manufacturers and finding something as "insignificant" as an oil filter that is drastically different across suppliers would be rather unusual. For example, my 2.0T CCTA engine uses a metal can spin-on with a plastic standoff for "upside down" mounting and all of the OE "German" ones available (VAG, Mann, Mahle, Hengst) are identical except for part numbers and labeling.

Yes, Hengst and Mahle are different. I have pictures of them too. There must be a reason for the only 4 small holes and I am still not sure why no other manufacturer would do the same way for whatever reason it was done

I have had Tiguan with CCTA and I cut open 17 or so filters and here is the clip and topic

That Fram stud on the picture above can happen to all brands. It is not hard removing it on the Fram and few others because they have that nasty hex cut off where you can use a wrench, while the well made Mann and the other rebrands you need a big pipe wrench

 

[ZeeOSix]

There must be a reason for the only 4 small holes and I am still not sure why no other manufacturer would do the same way for whatever reason it was done

Could be to keep the base plate ridged instead of making it thicker with more holes that wouldn't drop the dP across the base plate much to justify more holes. Even there are only 4 holes, they aren't that tiny in flow area.

 

[ZeeOSix]

This is how base plate holes can be misleading with respect to looking at them and trying to estimate how they flow oil.

This was the base plate on a Fram Ultra XG3600. It had 8 small holes, each only 0.20 inch in diameter. Total combined flow area of the 8 holes was only 0.251 in^2. Hot oil at 15 cSt is close to what 20W-50 would be at 100C (212F).

Even at a flow of 10 GPM through the base plate, the dP across the base plate was only 1.6 PSI. Even with the oil much thicker at 500 cSt, the dP was 3.0 PSI. A base plate with more or larger holes might drop the dP to 1.0 PSI with hot oil at 10 GPM. It really gets you nothing significant.