Are dirty oil filters more efficient?
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I think this is generally true, at the small (tiny?) risk of going into bypass more easily under extreme conditions.
Yes. The pores are getting clogged slowly.
Originally Posted By: LeakySeals
Yes. The pores are getting clogged slowly.
Or do the smaller pores get blocked first leaving the larger pores open?
I think filters probably get more efficient over time, up to a point. But I've always wondered about the above.
Yes. The pores are getting clogged slowly.
Or do the smaller pores get blocked first leaving the larger pores open?
I think filters probably get more efficient over time, up to a point. But I've always wondered about the above.
That's why I do 20K oil filter changes with 3 drain / refill oil changed.
Originally Posted By: spasm3
Originally Posted By: LeakySeals
Yes. The pores are getting clogged slowly.
Or do the smaller pores get blocked first leaving the larger pores open?
I think filters probably get more efficient over time, up to a point. But I've always wondered about the above.
Lol! good point. I assumed all the pores were the same size..
Originally Posted By: LeakySeals
Yes. The pores are getting clogged slowly.
Or do the smaller pores get blocked first leaving the larger pores open?
I think filters probably get more efficient over time, up to a point. But I've always wondered about the above.
Lol! good point. I assumed all the pores were the same size..
Originally Posted By: Mr Nice
That's why I do 20K oil filter changes with 3 drain / refill oil changed.
I would only do so with a filter spec'd for that long of an interval. Otherwise the filter might clog and go into bypass or tear.
That's why I do 20K oil filter changes with 3 drain / refill oil changed.
I would only do so with a filter spec'd for that long of an interval. Otherwise the filter might clog and go into bypass or tear.
Synthetic media has depth filtration, with multiple levels of "small" pores, it would take a major amount of dirt & sludge to completely block the media. Short of running conventional oil long past it's rated lifespan, IMO it would be hard to do. Since rebuilding my old '90 Civic wagon motor, which had a fair amount of sludge due to being ran with a bad radiator & a badly warped head, I haven't really had too many sludge issues.
Sorry to say this, but....This is simply another case of needing data.
Since there are so many variables a) media type, b) filter construction differences, c) engines' differing ways of making dirt, d) oils' additive packages response to dirt-does the oil's chemistry break down dirt clumps, for example; labs would need hundreds and hundreds of test combinations to answer the question.
As usual, oil analysis will answer your question in your setting. If you don't pay for oil analysis you simply must fall back on the "formula" of more frequent oil changes to be safe.
Since there are so many variables a) media type, b) filter construction differences, c) engines' differing ways of making dirt, d) oils' additive packages response to dirt-does the oil's chemistry break down dirt clumps, for example; labs would need hundreds and hundreds of test combinations to answer the question.
As usual, oil analysis will answer your question in your setting. If you don't pay for oil analysis you simply must fall back on the "formula" of more frequent oil changes to be safe.
Depends IMO. Glass media like in the Fram Ults, I would hypothesize, has a progressive increase in efficiency as it loads up. Paper and blend media might suffer an efficiency slump during the middle of the filter life as documents posted recently have suggested, and this may possibly be due to the inevitable moisture absorbing on the paper media, softening it some and allowing PSID to push some particulate through.
Originally Posted By: lukejo
Let's go with a high quality Fram Ultra for example. Assuming a well maintained engine, and that dirt is not so much as to "clog" the filter, would it filter more efficiently past the 10k mile mark?
I have heard air filters on air handler units get more efficent hater they have been in use for a while .
So , the same may be true with oil filters ?
Let's go with a high quality Fram Ultra for example. Assuming a well maintained engine, and that dirt is not so much as to "clog" the filter, would it filter more efficiently past the 10k mile mark?
I have heard air filters on air handler units get more efficent hater they have been in use for a while .
So , the same may be true with oil filters ?
I wouldn't take a chance on the oil filter going into Bypass over a tiny bump in filtering efficiency.
Let's say it does start to filter finer particles out and then BAM, it goes to into Bypass and doesn't filter JACK for the remaining 1,000 miles of your interval.
so what good did you accomplish?
Let's say it does start to filter finer particles out and then BAM, it goes to into Bypass and doesn't filter JACK for the remaining 1,000 miles of your interval.
Originally Posted By: Joenpb
I would only do so with a filter spec'd for that long of an interval. Otherwise the filter might clog and go into bypass or tear.
Generally (typically) - -
On a clean engine, ^^^^ this never happens
The "big stuff" the filter catches often isn't enough to plug it at all (dirty engines = different story)
The "small stuff" (less than 10 microns) goes right through, and that is what makes the oil dirty. The filter doesn't catch the stuff that "turns oil black" because it's too fine.
I would only do so with a filter spec'd for that long of an interval. Otherwise the filter might clog and go into bypass or tear.
Generally (typically) - -
On a clean engine, ^^^^ this never happens
The "big stuff" the filter catches often isn't enough to plug it at all (dirty engines = different story)
The "small stuff" (less than 10 microns) goes right through, and that is what makes the oil dirty. The filter doesn't catch the stuff that "turns oil black" because it's too fine.
According to Mann+Hummel, oil filters get a bit less efficient as they load up, except right at the end of the filter's life when it becomes almost clogged and the bypass valve opens up. Also, this phenomenon can be seen during data collection in the ISO 4548-12 efficiency test.
Yes, it seems illogical that this would happen, but test data shows the efficiency decreases slightly as the filter loads up.
There have been a few threads talking about this lately - like here: LINK
Yes, it seems illogical that this would happen, but test data shows the efficiency decreases slightly as the filter loads up.
There have been a few threads talking about this lately - like here: LINK
Originally Posted By: PeterPolyol
Depends IMO. Glass media like in the Fram Ults, I would hypothesize, has a progressive increase in efficiency as it loads up. Paper and blend media might suffer an efficiency slump during the middle of the filter life as documents posted recently have suggested, and this may possibly be due to the inevitable moisture absorbing on the paper media, softening it some and allowing PSID to push some particulate through.
Pure speculation.
Depends IMO. Glass media like in the Fram Ults, I would hypothesize, has a progressive increase in efficiency as it loads up. Paper and blend media might suffer an efficiency slump during the middle of the filter life as documents posted recently have suggested, and this may possibly be due to the inevitable moisture absorbing on the paper media, softening it some and allowing PSID to push some particulate through.
Pure speculation.
Originally Posted By: ZeeOSix
According to Mann+Hummel, oil filters get a bit less efficient as they load up, except right at the end of the filter's life when it becomes almost clogged and the bypass valve opens up. Also, this phenomenon can be seen during data collection in the ISO 4548-12 efficiency test.
Yes, it seems illogical that this would happen, but test data shows the efficiency decreases slightly as the filter loads up.
There have been a few threads talking about this lately - like here: LINK
Great info, I followed the links to the paper with these results and it was very interesting to flip through. I guess I still don't really get what's going on, but the facts are the facts.
Thanks for posting and exposing the [censored] I was peddling!
;^)
According to Mann+Hummel, oil filters get a bit less efficient as they load up, except right at the end of the filter's life when it becomes almost clogged and the bypass valve opens up. Also, this phenomenon can be seen during data collection in the ISO 4548-12 efficiency test.
Yes, it seems illogical that this would happen, but test data shows the efficiency decreases slightly as the filter loads up.
There have been a few threads talking about this lately - like here: LINK
Great info, I followed the links to the paper with these results and it was very interesting to flip through. I guess I still don't really get what's going on, but the facts are the facts.
Thanks for posting and exposing the [censored] I was peddling!
;^)
What's interesting is the ISO 4548-12 test procedure says to calculate the average efficiency for each measured particle size over the test run.
That means if a filter's average efficiency is 99% at 20 microns, then it doesn't exhibit much efficiency drop while going from new to nearly fully loaded. That tells me that the loss of efficiency due to loading is dependant on the media design.
It could be that oil filters that don't have a very high reported ISO 4548-12 efficiency are also the ones that probably exhibit the most drop in efficiency as they load up. The required ISO average efficiency calculation really drags down the efficiency if the media becomes a lot less efficient with use and debris loading.
IMO, this is another good reason to use filters with a high reported ISO efficiency number at 20 microns. I like anything that's 95% or better at 20 microns.
That means if a filter's average efficiency is 99% at 20 microns, then it doesn't exhibit much efficiency drop while going from new to nearly fully loaded. That tells me that the loss of efficiency due to loading is dependant on the media design.
It could be that oil filters that don't have a very high reported ISO 4548-12 efficiency are also the ones that probably exhibit the most drop in efficiency as they load up. The required ISO average efficiency calculation really drags down the efficiency if the media becomes a lot less efficient with use and debris loading.
IMO, this is another good reason to use filters with a high reported ISO efficiency number at 20 microns. I like anything that's 95% or better at 20 microns.
Just like dirty laundry water is more efficient.
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