oil filter selection
- Thread starter chevydude
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Any oil filter sould be fine with any oil unless your going for a 10,000 + mile OCI. Napa/Wix are very good filters in my book
Originally Posted By: chevydude
When using blended or synthetic oils, does the oil filter need to be different as far as inside material or does the same oil filter such as PF48 that is used on conventional used for the blended/synthetic oils out there.
Nothing special needed. Any filter can handle oil from dino to synthetic. The Fram orange filter is a cheaply made filter. There are better for not much more.
When using blended or synthetic oils, does the oil filter need to be different as far as inside material or does the same oil filter such as PF48 that is used on conventional used for the blended/synthetic oils out there.
Nothing special needed. Any filter can handle oil from dino to synthetic. The Fram orange filter is a cheaply made filter. There are better for not much more.
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When you hear the talk of "synthetic" oil filters, they are simply referring to the use of glass as the filtering medium instead of fiber/paper. The marketing for each oil filter recommends a "synthetic" oil filter for synthetic oil, only because you can do a longer OCI with synthetic oil, and these filters are "rated" for longer.
I put "rated" in parentheses because there are plenty of people on this forum that have good 10k OCIs on non-synthetic oil filters.
Majority of the $5 oil filters (excluding the Fram Extra Guard) have a synthetic blend for their filter media, partially glass and partially fiber. Purulator PureOne, NAPA Gold, Fram Tough Guard, Wix are all good syn blend filters. There are also higher end 10k+ OCI filters like Bosche Distance+, Fram Ultra Guard, and Purulator Synthetic that are designed for long drain OCIs.
Ultimately I'll take any oil filter that has a silicone anti-drain back valve. That and a pressure relief valve arguably play the most important role for a filter.
Bottomline: Any filter will work with synthetic oil.
I put "rated" in parentheses because there are plenty of people on this forum that have good 10k OCIs on non-synthetic oil filters.
Majority of the $5 oil filters (excluding the Fram Extra Guard) have a synthetic blend for their filter media, partially glass and partially fiber. Purulator PureOne, NAPA Gold, Fram Tough Guard, Wix are all good syn blend filters. There are also higher end 10k+ OCI filters like Bosche Distance+, Fram Ultra Guard, and Purulator Synthetic that are designed for long drain OCIs.
Ultimately I'll take any oil filter that has a silicone anti-drain back valve. That and a pressure relief valve arguably play the most important role for a filter.
Bottomline: Any filter will work with synthetic oil.
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Pick your filter on duration of OCI and features that are important to you, not the oil.
Just about any filter is good for 5k. Most "standard" filters will do 7.5k without problem IMO. Beyond that, I'd want an extended use filter.
Just about any filter is good for 5k. Most "standard" filters will do 7.5k without problem IMO. Beyond that, I'd want an extended use filter.
dnewton3
Staff member
Originally Posted By: chevydude
When using blended or synthetic oils, does the oil filter need to be different as far as inside material or does the same oil filter such as PF48 that is used on conventional used for the blended/synthetic oils out there.
Does it "need" to be? No.
But using a high-end filter really gains you nothing, if you don't extend the OCI. Filters are there to extend the life of oil. Therefore, if you don't extend the OCI, then both the syn lube and premium filter are under utilized; they are a waste in a "normal" OCI.
When using blended or synthetic oils, does the oil filter need to be different as far as inside material or does the same oil filter such as PF48 that is used on conventional used for the blended/synthetic oils out there.
Does it "need" to be? No.
But using a high-end filter really gains you nothing, if you don't extend the OCI. Filters are there to extend the life of oil. Therefore, if you don't extend the OCI, then both the syn lube and premium filter are under utilized; they are a waste in a "normal" OCI.
Originally Posted By: dnewton3
Filters are there to extend the life of oil.
By removing abrasive particles that cause engine wear? Guess I'm asking because I keep hearing that filters really don't help at all (or very little) in preventing engine wear, so I'm confused on how they actually extend the life of oil. Seems like contradictory thoughts are popping up now and then on the issue of engine wear and particulate in the oil.
Filters are there to extend the life of oil.
By removing abrasive particles that cause engine wear? Guess I'm asking because I keep hearing that filters really don't help at all (or very little) in preventing engine wear, so I'm confused on how they actually extend the life of oil. Seems like contradictory thoughts are popping up now and then on the issue of engine wear and particulate in the oil.
dnewton3
Staff member
It's the difference between correlation and causation.
Filters do nothing to directly affect the engine. They indirectly affect the relationship; they do not act directly.
Filters clean oil. Clean oil holds wear down. Three things have effects on wear; filtration, add-pack and OCI. They work in concert. Until the add-pack is overwhelmed, filters really don't mean as much as the other two.
Most certainly filters are important; I'd agree with that. But they are not the only actor in wear avoidance. Until the contamination level escalates, the filter really does not even have a lot to do. Until combustion byproducts overwhelm the detergents and dispersents, whereby the contamination becomes larger, the filter cannot even catch the particles as they are too small for a filter to have much effect.
But as the oil ages, and the proportion of particulate increases, the filter does increase its effects. And that in turn allows it to lengthen the lifecycle of the lube.
Lube extends the life of the equipment, while filters extend the useful life of the lube. The filters have an indirect effect on equipment.
Consider these two situational conditions:
a) fresh sump of oil, but no filter whatsoever. Engine would still easily run 3-5k miles before any major issue set in.
b) fresh filter, but no oil in the crankcase. Engine would run perhaps 3-5 minutes (if that) before it ground to a halt.
Lubes stay in service longer due to filtration.
Clean lubes can be achieved by more than one means.
You can either filter out contamination, or flush it out with an OCI. Either is effective; two means to the same end.
Filters do nothing to directly affect the engine. They indirectly affect the relationship; they do not act directly.
Filters clean oil. Clean oil holds wear down. Three things have effects on wear; filtration, add-pack and OCI. They work in concert. Until the add-pack is overwhelmed, filters really don't mean as much as the other two.
Most certainly filters are important; I'd agree with that. But they are not the only actor in wear avoidance. Until the contamination level escalates, the filter really does not even have a lot to do. Until combustion byproducts overwhelm the detergents and dispersents, whereby the contamination becomes larger, the filter cannot even catch the particles as they are too small for a filter to have much effect.
But as the oil ages, and the proportion of particulate increases, the filter does increase its effects. And that in turn allows it to lengthen the lifecycle of the lube.
Lube extends the life of the equipment, while filters extend the useful life of the lube. The filters have an indirect effect on equipment.
Consider these two situational conditions:
a) fresh sump of oil, but no filter whatsoever. Engine would still easily run 3-5k miles before any major issue set in.
b) fresh filter, but no oil in the crankcase. Engine would run perhaps 3-5 minutes (if that) before it ground to a halt.
Lubes stay in service longer due to filtration.
Clean lubes can be achieved by more than one means.
You can either filter out contamination, or flush it out with an OCI. Either is effective; two means to the same end.
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Originally Posted By: dnewton3
It's the difference between correlation and causation.
Filters do nothing to directly affect the engine. They indirectly affect the relationship; they do not act directly.
Filters clean oil. Clean oil holds wear down.
The way I look at it is if a filter cleans oil, which holds down engine wear, then they certainly do have a direct affect on engine wear. If you take the filter away completely, then the wear it can prevent is now present. So it does have direct affect in that regard. Just my viewpoint.
Originally Posted By: dnewton3
Most certainly filters are important; I'd agree with that. But they are not the only actor in wear avoidance.
I don't think anyone is claiming the filter is the only thing that keeps engine wear down. Is it the most important? ... probably not, but guess that depends on how dirty the oil becomes.
Originally Posted By: dnewton3
Lube extends the life of the equipment, while filters extend the useful life of the lube. The filters have an indirect effect on equipment.
As said earlier ... depends on one's viewpoint. Without a good filter the oil would become contaminated, therefore the filter is the direct contributor to preventing wear caused by oil contamination.
Originally Posted By: dnewton3
Consider these two situational conditions:
a) fresh sump of oil, but no filter whatsoever. Engine would still easily run 3-5k miles before any major issue set in.
Probably ... but what's a "major issue"? The engine blowing up? I'm sure you could take any engine and not run any oil filter and change oil every 3K miles and it would probably still be running at 100K miles. But if you had the same exact engine and ran it exactly the same but with a good oil filter on it you could probably tell the difference in engine wear at 100K miles.
Originally Posted By: dnewton3
b) fresh filter, but no oil in the crankcase. Engine would run perhaps 3-5 minutes (if that) before it ground to a halt.
Of course the oil is most important.
Originally Posted By: dnewton3
Lubes stay in service longer due to filtration. Clean lubes can be achieved by more than one means. You can either filter out contamination, or flush it out with an OCI. Either is effective; two means to the same end.
Obviously good filtration is the best method ... that's why high efficiency oil filters exist. Doubt anyone really wants to dump oil every 1000 miles these days to help keep engine wear down.
It's the difference between correlation and causation.
Filters do nothing to directly affect the engine. They indirectly affect the relationship; they do not act directly.
Filters clean oil. Clean oil holds wear down.
The way I look at it is if a filter cleans oil, which holds down engine wear, then they certainly do have a direct affect on engine wear. If you take the filter away completely, then the wear it can prevent is now present. So it does have direct affect in that regard. Just my viewpoint.
Originally Posted By: dnewton3
Most certainly filters are important; I'd agree with that. But they are not the only actor in wear avoidance.
I don't think anyone is claiming the filter is the only thing that keeps engine wear down. Is it the most important? ... probably not, but guess that depends on how dirty the oil becomes.
Originally Posted By: dnewton3
Lube extends the life of the equipment, while filters extend the useful life of the lube. The filters have an indirect effect on equipment.
As said earlier ... depends on one's viewpoint. Without a good filter the oil would become contaminated, therefore the filter is the direct contributor to preventing wear caused by oil contamination.
Originally Posted By: dnewton3
Consider these two situational conditions:
a) fresh sump of oil, but no filter whatsoever. Engine would still easily run 3-5k miles before any major issue set in.
Probably ... but what's a "major issue"? The engine blowing up? I'm sure you could take any engine and not run any oil filter and change oil every 3K miles and it would probably still be running at 100K miles. But if you had the same exact engine and ran it exactly the same but with a good oil filter on it you could probably tell the difference in engine wear at 100K miles.
Originally Posted By: dnewton3
b) fresh filter, but no oil in the crankcase. Engine would run perhaps 3-5 minutes (if that) before it ground to a halt.
Of course the oil is most important.
Originally Posted By: dnewton3
Lubes stay in service longer due to filtration. Clean lubes can be achieved by more than one means. You can either filter out contamination, or flush it out with an OCI. Either is effective; two means to the same end.
Obviously good filtration is the best method ... that's why high efficiency oil filters exist. Doubt anyone really wants to dump oil every 1000 miles these days to help keep engine wear down.
dnewton3
Staff member
This is about the difference of correlation and causation, period.
Finer filtration correlates with less engine wear; that is an indirect relationship.
Less contamination causes lower engine wear; that is a direct relationship.
You can achieve less wear by either flushing or filtering out contamination.
It's that simple.
This is where probably 99% or more folks get confused. The difference between correlation and causation.
Folks that read the famous (or infamous as I call it) GM filtration study synopsis don't get it either. Only when you truly read the entire study and understand the DOE does the "correlation" of the topic of filtration become apparent.
And you don't have to dump oil every 1000 miles to get low wear. In fact, although it may be counter-intuitive, that is the wrong thing to do. Anyone who wants to understand this topic needs to purchase and read SAE 2007-01-4133 and understand how wear is MAINLY controlled by the tribochemical barrier established via means of general oxidation of the lube. Yes - that's right; some amount of oxidation is actually beneficial. In fact, the anti-agglomerates (dispersents) can have a detrimental effect on the tribochemical barrier. That is why wear is actually accelerated towards the front end of the OCI when the add-pack is freshest. The longer the OCI runs, the less wear is seen, for quite some time. Most assuredly, contamination would eventually overcome any lube. But that limit is WAY, WAY further out than most folks think. And before anyone "poo-poo's" the SAE study I reference, understand that it is the second of such studies, and builds upon many other similar studies that contribute conceptually to the explanation of contributing circumstances and resultant consequences. They (Ford and Conoco) directly measured wear via electron-bombardment of the components; that is about as accurate as any method could ever hope to be. It was not an inferred wear rate, they were EXACTING measurments and clearly showed that wear rates drop as far out as 15k miles, to practically zero. There was no fancy filtration used. The lube came from Ford CV taxis in Las Vegas, run in everyday normal operation with normal filtration.
I have many thousands of UOAs in my database. I can tell you that when I run data to standardize for controllable criteria, there is no evidence whatsoever that "better" filtration results in less wear during a normal OCI. There simply is nothing to prove it to be so.
Again - I am not saying filtration isn't important. What I'm stating is that once a reasonable minimum threshold of filtration is achieved, anything overtly above that is unneeded and does not manifest into any significant difference in wear control.
Finer filtration correlates with less engine wear; that is an indirect relationship.
Less contamination causes lower engine wear; that is a direct relationship.
You can achieve less wear by either flushing or filtering out contamination.
It's that simple.
This is where probably 99% or more folks get confused. The difference between correlation and causation.
Folks that read the famous (or infamous as I call it) GM filtration study synopsis don't get it either. Only when you truly read the entire study and understand the DOE does the "correlation" of the topic of filtration become apparent.
And you don't have to dump oil every 1000 miles to get low wear. In fact, although it may be counter-intuitive, that is the wrong thing to do. Anyone who wants to understand this topic needs to purchase and read SAE 2007-01-4133 and understand how wear is MAINLY controlled by the tribochemical barrier established via means of general oxidation of the lube. Yes - that's right; some amount of oxidation is actually beneficial. In fact, the anti-agglomerates (dispersents) can have a detrimental effect on the tribochemical barrier. That is why wear is actually accelerated towards the front end of the OCI when the add-pack is freshest. The longer the OCI runs, the less wear is seen, for quite some time. Most assuredly, contamination would eventually overcome any lube. But that limit is WAY, WAY further out than most folks think. And before anyone "poo-poo's" the SAE study I reference, understand that it is the second of such studies, and builds upon many other similar studies that contribute conceptually to the explanation of contributing circumstances and resultant consequences. They (Ford and Conoco) directly measured wear via electron-bombardment of the components; that is about as accurate as any method could ever hope to be. It was not an inferred wear rate, they were EXACTING measurments and clearly showed that wear rates drop as far out as 15k miles, to practically zero. There was no fancy filtration used. The lube came from Ford CV taxis in Las Vegas, run in everyday normal operation with normal filtration.
I have many thousands of UOAs in my database. I can tell you that when I run data to standardize for controllable criteria, there is no evidence whatsoever that "better" filtration results in less wear during a normal OCI. There simply is nothing to prove it to be so.
Again - I am not saying filtration isn't important. What I'm stating is that once a reasonable minimum threshold of filtration is achieved, anything overtly above that is unneeded and does not manifest into any significant difference in wear control.
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Originally Posted By: dnewton3
And you don't have to dump oil every 1000 miles to get low wear. In fact, although it may be counter-intuitive, that is the wrong thing to do.
Anyone who wants to understand this topic needs to purchase and read SAE 2007-01-4133 and understand how wear is MAINLY controlled by the tribochemical barrier established via means of general oxidation of the lube.
I'm assuming you are talking here with the thought that there is a decent filter present - you didn't qualify one way or the other. If there was no oil filter during the whole OCI, then the level of contamination increases over the OCI. In order to keep the contaminates low in the oil when there is no filter, you would have to dump the oil at relatively low mileage. Was it Jim Allen that said he saw many VW engines that ran a pretty open strainer screen as a "filter", and those engines really didn't last very long before a rebuild was needed (much less than 100K miles).
Originally Posted By: dnewton3
The longer the OCI runs, the less wear is seen, for quite some time. Most assuredly, contamination would eventually overcome any lube. But that limit is WAY, WAY further out than most folks think. And before anyone "poo-poo's" the SAE study I reference, understand that it is the second of such studies, and builds upon many other similar studies that contribute conceptually to the explanation of contributing circumstances and resultant consequences. They (Ford and Conoco) directly measured wear via electron-bombardment of the components; that is about as accurate as any method could ever hope to be. It was not an inferred wear rate, they were EXACTING measurments and clearly showed that wear rates drop as far out as 15k miles, to practically zero. There was no fancy filtration used. The lube came from Ford CV taxis in Las Vegas, run in everyday normal operation with normal filtration.
So did they run any of those taxis in this test fleet with no oil filter at all (but keeping all other variables the same) to see what effect that had on wear?
Originally Posted By: dnewton3
Again - I am not saying filtration isn't important. What I'm stating is that once a reasonable minimum threshold of filtration is achieved, anything overtly above that is unneeded and does not manifest into any significant difference in wear control.
Hard to believe, but must be true of there is solid data to support it. But real question is, what exactly was the level of filtration used in these tests, and did they consider using no filtration or some known crummy filtration performance to see what effect it had on the wear?
And you don't have to dump oil every 1000 miles to get low wear. In fact, although it may be counter-intuitive, that is the wrong thing to do.
Anyone who wants to understand this topic needs to purchase and read SAE 2007-01-4133 and understand how wear is MAINLY controlled by the tribochemical barrier established via means of general oxidation of the lube.
I'm assuming you are talking here with the thought that there is a decent filter present - you didn't qualify one way or the other. If there was no oil filter during the whole OCI, then the level of contamination increases over the OCI. In order to keep the contaminates low in the oil when there is no filter, you would have to dump the oil at relatively low mileage. Was it Jim Allen that said he saw many VW engines that ran a pretty open strainer screen as a "filter", and those engines really didn't last very long before a rebuild was needed (much less than 100K miles).
Originally Posted By: dnewton3
The longer the OCI runs, the less wear is seen, for quite some time. Most assuredly, contamination would eventually overcome any lube. But that limit is WAY, WAY further out than most folks think. And before anyone "poo-poo's" the SAE study I reference, understand that it is the second of such studies, and builds upon many other similar studies that contribute conceptually to the explanation of contributing circumstances and resultant consequences. They (Ford and Conoco) directly measured wear via electron-bombardment of the components; that is about as accurate as any method could ever hope to be. It was not an inferred wear rate, they were EXACTING measurments and clearly showed that wear rates drop as far out as 15k miles, to practically zero. There was no fancy filtration used. The lube came from Ford CV taxis in Las Vegas, run in everyday normal operation with normal filtration.
So did they run any of those taxis in this test fleet with no oil filter at all (but keeping all other variables the same) to see what effect that had on wear?
Originally Posted By: dnewton3
Again - I am not saying filtration isn't important. What I'm stating is that once a reasonable minimum threshold of filtration is achieved, anything overtly above that is unneeded and does not manifest into any significant difference in wear control.
Hard to believe, but must be true of there is solid data to support it. But real question is, what exactly was the level of filtration used in these tests, and did they consider using no filtration or some known crummy filtration performance to see what effect it had on the wear?
dnewton3
Staff member
Sorry - didn't mean to leave behind a confusing trail.
Yes - the taxis had "normal" filters in use during the OCI runs for that SAE study package.
Quote:
But real question is, what exactly was the level of filtration used in these tests, and did they consider using no filtration or some known crummy filtration performance to see what effect it had on the wear?
I cannot tell you what ISO spec they (Ford) defined, but it is reflected in every filter we purchase for any known application. Nor can I tell you what they considered to do in the study; I can only tell you what they actually did. IOW - I cannot speculate on what they mulled over at the bar while scribbling on a napkin, hypothesizing the DOE. We only know what the study tells us; we don't know what the study does not tell us because we cannot know for sure what was omitted by purposeful or accidental exclusion, in regard to other filtration options. Yes - they could have decided to run low quality filters, or no filters; but that was not addressed in the study. The topic for the study was the affect of OCI duration on wear. The two variables manipulated were the OCI and the type of lube (they used three difference add-packages to validate the fact that the phenomenon was not unique to one lube add-pack, but generally applicable to many lubes). Being that this SAE study was a Ford/Conoco endeavor, I rather suspect they used the FL-820; that's the standard filter for the 4.6L Mod motor in the CV. Past that, I cannot tell you what "minimum threshold" filtration is needed; I only know what they used.
As you and I would likely agree, there are two ways the aftermarket spec's a filter for any application:
1) they get the direct specs from the OEM at match accordingly
2) they purchase some OEM filters for testing and reverse engineer a filter with as-good-or-better performance
So it really does not matter what the OEM spec is; the aftermarket is going to be at or above that performance level. For each separate application, there might likely be small differences. But for each application, there will always be filters that are more than "good enough" to easily support the OEM OCI intent, and often way past that.
My 2000 Galant has a OEM "normal" OCI of 7.5k miles, and the "normal" FCI is 2x that, at 15k miles. No fancy high-end filter needed per the manual. I recently bought the car used; it's in good shape. I'm running an ARX cycle just to clean it, even though it really looked very good on the top end; it was a precautionary move. Once I'm done with that flush/rinse, I'm going to run some 7.5k/15k mile OCIs with 15k mile FCIs and then UOA. Stay tuned ...
Hope that clarifies a bit; my apology for not being a clear as I had initially intended.
Yes - the taxis had "normal" filters in use during the OCI runs for that SAE study package.
Quote:
But real question is, what exactly was the level of filtration used in these tests, and did they consider using no filtration or some known crummy filtration performance to see what effect it had on the wear?
I cannot tell you what ISO spec they (Ford) defined, but it is reflected in every filter we purchase for any known application. Nor can I tell you what they considered to do in the study; I can only tell you what they actually did. IOW - I cannot speculate on what they mulled over at the bar while scribbling on a napkin, hypothesizing the DOE. We only know what the study tells us; we don't know what the study does not tell us because we cannot know for sure what was omitted by purposeful or accidental exclusion, in regard to other filtration options. Yes - they could have decided to run low quality filters, or no filters; but that was not addressed in the study. The topic for the study was the affect of OCI duration on wear. The two variables manipulated were the OCI and the type of lube (they used three difference add-packages to validate the fact that the phenomenon was not unique to one lube add-pack, but generally applicable to many lubes). Being that this SAE study was a Ford/Conoco endeavor, I rather suspect they used the FL-820; that's the standard filter for the 4.6L Mod motor in the CV. Past that, I cannot tell you what "minimum threshold" filtration is needed; I only know what they used.
As you and I would likely agree, there are two ways the aftermarket spec's a filter for any application:
1) they get the direct specs from the OEM at match accordingly
2) they purchase some OEM filters for testing and reverse engineer a filter with as-good-or-better performance
So it really does not matter what the OEM spec is; the aftermarket is going to be at or above that performance level. For each separate application, there might likely be small differences. But for each application, there will always be filters that are more than "good enough" to easily support the OEM OCI intent, and often way past that.
My 2000 Galant has a OEM "normal" OCI of 7.5k miles, and the "normal" FCI is 2x that, at 15k miles. No fancy high-end filter needed per the manual. I recently bought the car used; it's in good shape. I'm running an ARX cycle just to clean it, even though it really looked very good on the top end; it was a precautionary move. Once I'm done with that flush/rinse, I'm going to run some 7.5k/15k mile OCIs with 15k mile FCIs and then UOA. Stay tuned ...
Hope that clarifies a bit; my apology for not being a clear as I had initially intended.
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I see the oil and the filter connected synergistically.
Remember that contamination begets wear, which begets more wear, which begets even more wear... and that's what's called the "chain reaction of wear." It's all about keeping the contamination level as low as possible for as long as possible and that's what the filter does. The oil helps prevent wear, and thus reduces further contamination FROM wear, but there are contamination inputs beyond the wear metals generated by the engine and these probably have as much or more to do with wear than what is produced by "normal" wear itself.
What are some of the relevant inputs to oil contamination?:
1) Built in contamination from manufacture. Most of this gets filtered pretty quickly but it really wreaks havoc first and creates even more particles... many of which are too small to be captured by the filter. Though most of it is flushed out quickly, it may take a while for all of it to be captured.
2) Overall, the biggest contributor to contamination inputs is the air intake. A lot of harmful particles that come thru the intake are blown past the rings by combustion. As they grind past the rings, they are broken up and in the process takes metal off the rings and cylinder walls, which become even more contamination. From there, that material does it's nasty work wherever it goes until (or if) it's filtered or drained out. This input is never-ending as long as the engine is running, making air filtration as important (maybe more so) than oil filtration.
3) Wear metals. Early on, as the engine break in, there are a lot of them being produced, but they taper off to a "normal" low rate (for that engine in it's normal environment). As long as the other inputs are low, this input stays low as well, especially if the oil is doing it's job.
4) Combustion: Blowby produces gasses and fuel dilution that effects the oil directly, which effects wear indirectly by degrading the oil's ability to reduce wear (sooner or later). As to some direct particulate contamination from the combustion process, with gas engines, there is some hard carbon particles that can migrate down the cylinder walls. Diesel soot is a big contributor to particulate contamination and oil degradation.
So, we know from the famous, or infamous, GM filtration study, and others, approximately how much wear occurs with high levels of contamination and that higher levels produce more wear.
We know less about what happens with contamination at lower levels. I have not seen any detailed studies that measure wear at oil contamination levels we see as "normal" e.g. what you might see at the end of a typical OCI with a normal filter, let alone any that shows the wear with a finer level of filtration. This is likely because at lower levels of contamination, wear is much more difficult to measure. You'd have to make long dyno runs which cost money. It's easy to rapidly and artificially increase the contamination level and measure wear at high levels. To measure the difference between a 35-40 um abs "ordinary" filter and a 20 um abs "premium" filter would probably take years of dyno time, or a very controlled study in vehicles on the road.
One notable and real-world (in the HD realm anyway) test I saw in the Pall Corp paper, "Diesel Engine Lubrication Contamination and Wear" (Addison & Needelman) included a chart that showed the contamination levels of oils in diesels used in a mine, some with a 60 um abs "paper" filter and the others with a 10 um abs synthetic filter over 500 hours of running. The level of contamination was 20 times more with the 60 um filter than with the 10 um and the finer filter was reported to have more than twice the service life. Though they did not detail the UOAs they took, they stated:
"Spectrographic oil analysis revealed significant reductions in wear metals on those engines using composite-cynthetic medium filters. Since the accuracy of spectrographic oil analysis is severely limited for particles 5 microns and larger, these results do not completely reflect the dramatic reduction in wear debris achieved with the composite-synthetic filter medium."
How much the wear is created by contamination may be determined by the type of engine. The most wear prone areas are those with the least clearance and the least amount of oil flow. According to a chart in the Pall paper (it's handy but I've seen similar elsewhere), the tightest clearances are in the valvetrain, drive gears and and the piston rings. I would add a flat tappet cam. Interestingly, these are not places where there is a high flow to oil to make a good hydrodynamic wedge (>2 um). Engines with roller valvetrains are the least effected by contamination. The rings are most effected by the small
Given all the evidence, logic dictates that less contamination simply has to result in less wear but it's maddening not to see it reflected in UOAs. As I said before, the levels of contamination rise very slowly in the real world (the street environment with good air filtration and a sealed crankcase), so there are long periods of relatively clean oil, even without extraordinary filtration. When the rate of contamination is very slow, mostly coming only from the small amount of engine wear and the small amount that gets thru the air filter, it takes a long while for the level of contamination to rise to the point of being a problem in terms of increasing wear. In many cases, the oil is changed before that occurs. This is why Dave Newton can find no statistical evidence in UOAs to support an assertion that improved filtration has any effect on wear in the real world. But I would also think that given the fairly blurry picture we get from a UOA, it may not be telling the whole story either.
I think what Dave tells us statistically is exactly the same thing the OEM and aftermarket filter manufacturers do, that the current (or ordinary, customary) level of filtration is "good enough." The gains from improved filtration become harder to justify economically at a certain point (to me that "certain point" is a 30-35 um abs level of filtration) even if gains are present.
BUT! The key to this is to control the other inputs, most especially air filtration. That will be the killer long term. Fine air filtration levels leave little for the oil filter to do and reduces wear a lot.
I think diesels have more to gain from oil filtration than gassers. The soot aspects, especially with the newer EGR equipped diesels, make for a better potential payoffs. Keeping the soot levels low definitely extends oil life. I think this statement is justified by the many diesel that have fine bypass filtration OE.
Commenting on my previous comment about air cooled VWs: Yes, I rebuilt a lot of them and the only oil filtration they had was a screen that was not much tighter than a kitchen collender. They ran pretty loose bearing clearances and flowed a lot of oil. The oci was 2-3000 miles as I recall. I saw few engines that lasted longer than 75K but I can't say honestly that it was all oil related or that the failures were bottom-end related. Usually it was burned valves. BUT, when the engines were torn down for any reason, the bearings were usually pretty wiped out. Heavily embedded and scratched up... ditto the crankshaft.
Remember that contamination begets wear, which begets more wear, which begets even more wear... and that's what's called the "chain reaction of wear." It's all about keeping the contamination level as low as possible for as long as possible and that's what the filter does. The oil helps prevent wear, and thus reduces further contamination FROM wear, but there are contamination inputs beyond the wear metals generated by the engine and these probably have as much or more to do with wear than what is produced by "normal" wear itself.
What are some of the relevant inputs to oil contamination?:
1) Built in contamination from manufacture. Most of this gets filtered pretty quickly but it really wreaks havoc first and creates even more particles... many of which are too small to be captured by the filter. Though most of it is flushed out quickly, it may take a while for all of it to be captured.
2) Overall, the biggest contributor to contamination inputs is the air intake. A lot of harmful particles that come thru the intake are blown past the rings by combustion. As they grind past the rings, they are broken up and in the process takes metal off the rings and cylinder walls, which become even more contamination. From there, that material does it's nasty work wherever it goes until (or if) it's filtered or drained out. This input is never-ending as long as the engine is running, making air filtration as important (maybe more so) than oil filtration.
3) Wear metals. Early on, as the engine break in, there are a lot of them being produced, but they taper off to a "normal" low rate (for that engine in it's normal environment). As long as the other inputs are low, this input stays low as well, especially if the oil is doing it's job.
4) Combustion: Blowby produces gasses and fuel dilution that effects the oil directly, which effects wear indirectly by degrading the oil's ability to reduce wear (sooner or later). As to some direct particulate contamination from the combustion process, with gas engines, there is some hard carbon particles that can migrate down the cylinder walls. Diesel soot is a big contributor to particulate contamination and oil degradation.
So, we know from the famous, or infamous, GM filtration study, and others, approximately how much wear occurs with high levels of contamination and that higher levels produce more wear.
We know less about what happens with contamination at lower levels. I have not seen any detailed studies that measure wear at oil contamination levels we see as "normal" e.g. what you might see at the end of a typical OCI with a normal filter, let alone any that shows the wear with a finer level of filtration. This is likely because at lower levels of contamination, wear is much more difficult to measure. You'd have to make long dyno runs which cost money. It's easy to rapidly and artificially increase the contamination level and measure wear at high levels. To measure the difference between a 35-40 um abs "ordinary" filter and a 20 um abs "premium" filter would probably take years of dyno time, or a very controlled study in vehicles on the road.
One notable and real-world (in the HD realm anyway) test I saw in the Pall Corp paper, "Diesel Engine Lubrication Contamination and Wear" (Addison & Needelman) included a chart that showed the contamination levels of oils in diesels used in a mine, some with a 60 um abs "paper" filter and the others with a 10 um abs synthetic filter over 500 hours of running. The level of contamination was 20 times more with the 60 um filter than with the 10 um and the finer filter was reported to have more than twice the service life. Though they did not detail the UOAs they took, they stated:
"Spectrographic oil analysis revealed significant reductions in wear metals on those engines using composite-cynthetic medium filters. Since the accuracy of spectrographic oil analysis is severely limited for particles 5 microns and larger, these results do not completely reflect the dramatic reduction in wear debris achieved with the composite-synthetic filter medium."
How much the wear is created by contamination may be determined by the type of engine. The most wear prone areas are those with the least clearance and the least amount of oil flow. According to a chart in the Pall paper (it's handy but I've seen similar elsewhere), the tightest clearances are in the valvetrain, drive gears and and the piston rings. I would add a flat tappet cam. Interestingly, these are not places where there is a high flow to oil to make a good hydrodynamic wedge (>2 um). Engines with roller valvetrains are the least effected by contamination. The rings are most effected by the small
Given all the evidence, logic dictates that less contamination simply has to result in less wear but it's maddening not to see it reflected in UOAs. As I said before, the levels of contamination rise very slowly in the real world (the street environment with good air filtration and a sealed crankcase), so there are long periods of relatively clean oil, even without extraordinary filtration. When the rate of contamination is very slow, mostly coming only from the small amount of engine wear and the small amount that gets thru the air filter, it takes a long while for the level of contamination to rise to the point of being a problem in terms of increasing wear. In many cases, the oil is changed before that occurs. This is why Dave Newton can find no statistical evidence in UOAs to support an assertion that improved filtration has any effect on wear in the real world. But I would also think that given the fairly blurry picture we get from a UOA, it may not be telling the whole story either.
I think what Dave tells us statistically is exactly the same thing the OEM and aftermarket filter manufacturers do, that the current (or ordinary, customary) level of filtration is "good enough." The gains from improved filtration become harder to justify economically at a certain point (to me that "certain point" is a 30-35 um abs level of filtration) even if gains are present.
BUT! The key to this is to control the other inputs, most especially air filtration. That will be the killer long term. Fine air filtration levels leave little for the oil filter to do and reduces wear a lot.
I think diesels have more to gain from oil filtration than gassers. The soot aspects, especially with the newer EGR equipped diesels, make for a better potential payoffs. Keeping the soot levels low definitely extends oil life. I think this statement is justified by the many diesel that have fine bypass filtration OE.
Commenting on my previous comment about air cooled VWs: Yes, I rebuilt a lot of them and the only oil filtration they had was a screen that was not much tighter than a kitchen collender. They ran pretty loose bearing clearances and flowed a lot of oil. The oci was 2-3000 miles as I recall. I saw few engines that lasted longer than 75K but I can't say honestly that it was all oil related or that the failures were bottom-end related. Usually it was burned valves. BUT, when the engines were torn down for any reason, the bearings were usually pretty wiped out. Heavily embedded and scratched up... ditto the crankshaft.
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