Post by s54smg2 on Feb 26, 2014 11:42:32 GMT -5
Do oil filters matter?
That depends on who you talk to...or what you read.
The late, great Bob Winters of Bobistheoilguy.com fame ran his car with the oil filter completely bypassed to see if it would make a difference on used oil laboratory analysis results. Apparently there was no conclusive evidence that the filter made any difference in the oil contamination levels that the laboratory analysis could detect.
Since there seems to be a limit in particle size that oil analysis labs can detect, this does not necessarily mean there were no filterable abrasive particles in the oil anyway.
Remember the original Volkswagen Beetle?
These engines originally used no filters at all and they seemed to reach 100,000 miles at least as often as other cars' engines that had filters. To be fair, the strategy for a well maintained, long lived old VW engine was to change the oil about twice as often as filtered engines required it. This would certainly get rid of most of the build up of abrasive particles and sludge in the VW engine.
-Ford Motor Company experimented with some of the first full flow oil filters (the modern method where all oil must pass through the filter on the way to the engine internals) back in the 1950s and found an approximate halving of abrasive engine wear...And this with the likely primitive filter media available at the time.
-Other credible sources say that the filter you choose is more important to engine longevity than the oil you use.
...But then again, look how cars so often go 200,000 or even 300,000 miles nowadays with little owner thought or knowlege about filters or oil. They just use whatever the shop or oil change place uses.
Flow vs Filtration
There are 2 schools of thought here:
1. Those who want maximum oil flow and figure that any particles hitting the filter repeatedly will be mostly caught after a few passes. These folks want a filter to be as unrestrictive as possible - even if the media is rather "coarse" and permeable to debris.
2. Those that feel they want as much debris as possible to be caught as quickly as possible by a "fine" filter media, and are not concerned by the relatively small oil pressure drop across the oil filter.
Who is right?
This is something of a judgment call because there is a logic to both people's preferences. Personally, I lean toward the second school of thought because the first one assumes that a load of debris is put into the oil at one time with no more debris being added. In this case, the filter will likely catch almost all of the debris in successive passes. In reality, there will be a continuous generation of particulate debris as the engine is run. There will be carbon and sludge, and there will be wear particles and also dust getting into the engine that makes it past the air cleaner. This is why multipass tests generally show a lower efficiency percentage than single pass tests - "dirt" is being continually added to the oil going through the filter being tested.
I have seen little evidence that any correctly selected name brand oil filter is much more than "invisible" to the oil pressure system as a whole. There may be some exceptions for a few picky engines that use small, high efficiency filters, or in racing applications. I try to choose a happy medium between flow and absolute per pass filtration.
Some of my comparisons will show a 2 or 3 fold difference in time that is takes the filter center tube to fill with oil. This should not be taken as that there would be a 2 or 3 fold reduction in oil flow to the engine. I look at it this way: "Filter A" may drop 3 psi when "Filter B" would be dropping only 1 psi. But out of, for example, 60 psi oil pressure to the engine parts, it makes no real difference.
Another thing is that just because a filter has a "fine" and efficient media, that does not preclude an easy passage of oil. There are wide variations in media composition, quantity, and media thickness in any given filter size. A filter with a larger quantity of media, all other things being equal, will pass oil more easily.
Whatever you choose...
Whichever type of filter you choose and whichever flow vs filtration characteristics you are comfortable with, it is my understanding that all oil filters must pass certain requirements. This is probably true, and a reputable filter that is advertised as meeting or exceeding car manufacturer or OEM specifications will likely serve you well in the long run.
Filter Construction and Terminology
Oil filters are usually constructed pretty much the same, overall. Dirty oil under pressure flows into the outer ring of holes on the baseplate, then pushes past an anti-drain-back valve on its way to the filter element (the element is the stucture that holds the "paper" media as the top left header picture shows), the dirty oil is then forced through the media which filters it, through the perforated center tube (above right), and out to the engine through the big, threaded center hole of the base-plate.
Should the media become clogged, or the oil too cold and thick to be forced through the media in proper quantity, a bypass valve is forced open (above right picture - center of the tube) to allow unfiltered oil to get to the engine. This is critical. Some filters do not have these, as it is part of the engine itself. One reason it is important to match the filter to the engine.
The anti-drain-back valve is normally just a rubbery disc that allows oil into he filter, but resists the oil from draining back out. This is to help keep oil ready to go in the filter and prevent "dry-starts" after the engine is shut off.
There are some differences in not just the quality and quantity of the filtering media, but the type and strength of the materials that hold it all together. Racing or off-road filters tend to have heavier canisters to resist puncturing by rocks or other debris. Since most filters are fairly well up out of the way of ground debris, and most of us do not race, I don't pay a lot of attention to certain physical characterisics such as this.
The two main things about construction that seem to matter to many people who are picky about the oil filters they buy, are the material that the anti-drainback valve (ADBV) is made of, and the location of the bypass valve.
Silicon and nitrile are the usual materials for the ADBV. Silicon is supposed to be more temperature stable of the two and remain flexible better for long oil change intervals. Premium filters often tout their silicon ADBV right on the box. Hopefully, either one will seal properly for a reasonable oil filter life, but the silicon version probably really is better.
Some filters have the bypass valve on or near the threaded baseplate, and some have it on the opposite end - often called the "dome end" of the filter.
The advantage of a threaded end bypass is that if and when the filter goes into bypass mode, the unfiltered oil from the oil pan is pumped around the media without first flowing past it.
When a dome end bypass opens, the oil flows past this media on the "dirty side" of the filter, there is the possibility of some of the previously captured debris being swept back into the engine oil.
I do not feel that this is not a big problem with dome end bypasses since there will still be pressure against, and usually some oil flowing through the media, tending to hold filtered debris in place.
Test Pictures and Results
Conclusions
My own category picks after all these examinations are as follows:
Filtration:
1. Delco UPF 52
2. PureOne, Bosch Premium, and Donaldson
3. Purolator Classic, Mobil 1 Ext Perf. and K&N, Mann, Fram Extended Guard
4. Wix/NAPA Gold and Wix built Delco Duraguard PF53, Mahle
5. Ecore style AC/Delco, Supetech, STP, and Fram Extraguard
6. Denso, Honda, Hamp
Construction:
1. Mobil 1 and K&N
2. Wix/NAPA Gold, Fram Extended Guard, Mann, Mahle
3. Purolator, Bosch Premium and PureOne
4. Denso, Honda, Hamp
5. Ecore style AC/Delco, Supetech, STP
6. Fram Extraguard
Easy oil flow:
1. Denso, Honda, Hamp
2. Mann, Mahle, Purolator Classic, Proline, Fram Extraguard, Fram Toughguard
3. Mobil 1, K&N, Wix/NAPA Gold,
4. PureOne, and Bosch Premium
5. Ecore style AC/Delco, Supetech, STP
6. Delco UPF52 , Fram Extended Guard
Not all test were done on all filters as you can see.
Any of these sample filters tested will filter your oil and should do the job. If you want maximum flow with absolute minimum pressure drop from the filter, you may decide to choose from very low restriction filters.
I hope by putting up these pictures and descriptions, you have a better idea of the variations in different aspects of performance, as far as they show up in these simple media tests.
Oil Filtration Comparisons From the Workbench
That depends on who you talk to...or what you read.
The late, great Bob Winters of Bobistheoilguy.com fame ran his car with the oil filter completely bypassed to see if it would make a difference on used oil laboratory analysis results. Apparently there was no conclusive evidence that the filter made any difference in the oil contamination levels that the laboratory analysis could detect.
Since there seems to be a limit in particle size that oil analysis labs can detect, this does not necessarily mean there were no filterable abrasive particles in the oil anyway.
Remember the original Volkswagen Beetle?
These engines originally used no filters at all and they seemed to reach 100,000 miles at least as often as other cars' engines that had filters. To be fair, the strategy for a well maintained, long lived old VW engine was to change the oil about twice as often as filtered engines required it. This would certainly get rid of most of the build up of abrasive particles and sludge in the VW engine.
-Ford Motor Company experimented with some of the first full flow oil filters (the modern method where all oil must pass through the filter on the way to the engine internals) back in the 1950s and found an approximate halving of abrasive engine wear...And this with the likely primitive filter media available at the time.
-Other credible sources say that the filter you choose is more important to engine longevity than the oil you use.
...But then again, look how cars so often go 200,000 or even 300,000 miles nowadays with little owner thought or knowlege about filters or oil. They just use whatever the shop or oil change place uses.
Flow vs Filtration
There are 2 schools of thought here:
1. Those who want maximum oil flow and figure that any particles hitting the filter repeatedly will be mostly caught after a few passes. These folks want a filter to be as unrestrictive as possible - even if the media is rather "coarse" and permeable to debris.
2. Those that feel they want as much debris as possible to be caught as quickly as possible by a "fine" filter media, and are not concerned by the relatively small oil pressure drop across the oil filter.
Who is right?
This is something of a judgment call because there is a logic to both people's preferences. Personally, I lean toward the second school of thought because the first one assumes that a load of debris is put into the oil at one time with no more debris being added. In this case, the filter will likely catch almost all of the debris in successive passes. In reality, there will be a continuous generation of particulate debris as the engine is run. There will be carbon and sludge, and there will be wear particles and also dust getting into the engine that makes it past the air cleaner. This is why multipass tests generally show a lower efficiency percentage than single pass tests - "dirt" is being continually added to the oil going through the filter being tested.
I have seen little evidence that any correctly selected name brand oil filter is much more than "invisible" to the oil pressure system as a whole. There may be some exceptions for a few picky engines that use small, high efficiency filters, or in racing applications. I try to choose a happy medium between flow and absolute per pass filtration.
Some of my comparisons will show a 2 or 3 fold difference in time that is takes the filter center tube to fill with oil. This should not be taken as that there would be a 2 or 3 fold reduction in oil flow to the engine. I look at it this way: "Filter A" may drop 3 psi when "Filter B" would be dropping only 1 psi. But out of, for example, 60 psi oil pressure to the engine parts, it makes no real difference.
Another thing is that just because a filter has a "fine" and efficient media, that does not preclude an easy passage of oil. There are wide variations in media composition, quantity, and media thickness in any given filter size. A filter with a larger quantity of media, all other things being equal, will pass oil more easily.
Whatever you choose...
Whichever type of filter you choose and whichever flow vs filtration characteristics you are comfortable with, it is my understanding that all oil filters must pass certain requirements. This is probably true, and a reputable filter that is advertised as meeting or exceeding car manufacturer or OEM specifications will likely serve you well in the long run.
Filter Construction and Terminology
Oil filters are usually constructed pretty much the same, overall. Dirty oil under pressure flows into the outer ring of holes on the baseplate, then pushes past an anti-drain-back valve on its way to the filter element (the element is the stucture that holds the "paper" media as the top left header picture shows), the dirty oil is then forced through the media which filters it, through the perforated center tube (above right), and out to the engine through the big, threaded center hole of the base-plate.
Should the media become clogged, or the oil too cold and thick to be forced through the media in proper quantity, a bypass valve is forced open (above right picture - center of the tube) to allow unfiltered oil to get to the engine. This is critical. Some filters do not have these, as it is part of the engine itself. One reason it is important to match the filter to the engine.
The anti-drain-back valve is normally just a rubbery disc that allows oil into he filter, but resists the oil from draining back out. This is to help keep oil ready to go in the filter and prevent "dry-starts" after the engine is shut off.
There are some differences in not just the quality and quantity of the filtering media, but the type and strength of the materials that hold it all together. Racing or off-road filters tend to have heavier canisters to resist puncturing by rocks or other debris. Since most filters are fairly well up out of the way of ground debris, and most of us do not race, I don't pay a lot of attention to certain physical characterisics such as this.
The two main things about construction that seem to matter to many people who are picky about the oil filters they buy, are the material that the anti-drainback valve (ADBV) is made of, and the location of the bypass valve.
Silicon and nitrile are the usual materials for the ADBV. Silicon is supposed to be more temperature stable of the two and remain flexible better for long oil change intervals. Premium filters often tout their silicon ADBV right on the box. Hopefully, either one will seal properly for a reasonable oil filter life, but the silicon version probably really is better.
Some filters have the bypass valve on or near the threaded baseplate, and some have it on the opposite end - often called the "dome end" of the filter.
The advantage of a threaded end bypass is that if and when the filter goes into bypass mode, the unfiltered oil from the oil pan is pumped around the media without first flowing past it.
When a dome end bypass opens, the oil flows past this media on the "dirty side" of the filter, there is the possibility of some of the previously captured debris being swept back into the engine oil.
I do not feel that this is not a big problem with dome end bypasses since there will still be pressure against, and usually some oil flowing through the media, tending to hold filtered debris in place.
Test Pictures and Results
Conclusions
My own category picks after all these examinations are as follows:
Filtration:
1. Delco UPF 52
2. PureOne, Bosch Premium, and Donaldson
3. Purolator Classic, Mobil 1 Ext Perf. and K&N, Mann, Fram Extended Guard
4. Wix/NAPA Gold and Wix built Delco Duraguard PF53, Mahle
5. Ecore style AC/Delco, Supetech, STP, and Fram Extraguard
6. Denso, Honda, Hamp
Construction:
1. Mobil 1 and K&N
2. Wix/NAPA Gold, Fram Extended Guard, Mann, Mahle
3. Purolator, Bosch Premium and PureOne
4. Denso, Honda, Hamp
5. Ecore style AC/Delco, Supetech, STP
6. Fram Extraguard
Easy oil flow:
1. Denso, Honda, Hamp
2. Mann, Mahle, Purolator Classic, Proline, Fram Extraguard, Fram Toughguard
3. Mobil 1, K&N, Wix/NAPA Gold,
4. PureOne, and Bosch Premium
5. Ecore style AC/Delco, Supetech, STP
6. Delco UPF52 , Fram Extended Guard
Not all test were done on all filters as you can see.
Any of these sample filters tested will filter your oil and should do the job. If you want maximum flow with absolute minimum pressure drop from the filter, you may decide to choose from very low restriction filters.
I hope by putting up these pictures and descriptions, you have a better idea of the variations in different aspects of performance, as far as they show up in these simple media tests.
Oil Filtration Comparisons From the Workbench