Not all oiled filters are similarly bad to K&N...

[SubieRubyRoo]

I have the S&B intake with oiled filter, and there had been some comments that it was a "rock catcher". I found this while searching for a replacement element, I'm at about 45k on the filter but there is no visible discoloration or accumulation of debris. Says the factory and the dry replacement options are only 0.4% more efficient than their oiled option... way better than K&N! Attachment is a PDF from S&B's website; very thorough and shows ISO testing methods and their comparisons to stock element.

 

[2strokeNorthstar]

These companies create tests to sell products. They found a certain size/type of dust that it will filter out. Doesn't mean that in the real world it performs. Does it matter? 3 of my vehicles have a dry flow synthetic filter for many years. All have high miles now and no know downside, yet anyway.

 

[Revving2Redline]

I would like to take the test of the oiled air filters and make them go through a cold weather test. I'm curious at what the freezing point is of the tact oil they use as well as whatever k&n and AFE. take those vehicles up to Yellowknife in the Northwest Territories in the midst of winter or Siberia. if that oil gets rock hard then it won't filter anything and I think the results would be different. now this isn't me being argumentative because I have no skin in The game everyone is welcome to use whatever filter that they want because they are buying their own stuff and as long as people are buying their own stuff then they are entitled to both their own opinion but not facts. furthermore, I don't have the facts to publish it's just a thought process that I recently paid attention to and thought why haven't they tested it to see how it would filter an extreme cold. we've got a lot of our workers or at least we did that were drilling in cold climate and there still is a lot of dirt and debris that gets shuffled around especially with high winds. another thought that I would like to ponder is what about areas that have extreme high humidity? as we all know once you are done cleaning one of these filters they have to completely dry before you start to oil them. if you have humidity like in Florida can that affect the filtration is that type of humidity would certainly build in between the pleats of the filter I would think. these are just some tests and some thoughts that I had and I'm not pitching project farm or anyone else to do them just simply trying to be a contributing member of things to discuss.

 

[twX]

Keep in mind that these tests were done with ISO Coarse dust, whereas many air filter tests are done with ISO A2 Fine dust, which is more representative of the particle size distribution of dust in a typical driving environment. ISO fine dust contains around 3-4 times more dust in the 1-10 micron range, which are the most difficult sizes to filter and also the most damaging to engines.

Still, 99.3% efficiency with coarse dust is respectable. It's unclear whether S&B is quoting initial, average, or final efficiency, but I'd guess it's the latter since it's better for marketing. They also don't mention the total test time, dust ingested, or final differential pressure, so they could have loaded the filter with the optimal amount of dust that would achieve the best average or final efficiency. I'd take their claims with a grain of salt, but I expect that this filter is still a lot better than a K&N.

That "0.4%" difference in efficiency vs the stock filter may seem small, but it will result in the engine ingesting over twice as much dust, which could double the wear rate of the piston rings. For a vehicle that's only driven on paved roads, that's unlikely to be an issue, but for a vehicle that drives in dusty environments, it could be.

 

[SubieRubyRoo]

These companies create tests to sell products. They found a certain size/type of dust that it will filter out. Doesn't mean that in the real world it performs. Does it matter? 3 of my vehicles have a dry flow synthetic filter for many years. All have high miles now and no know downside, yet anyway.

We weren't arguing about dry filters, seems we both agree there. Was just sharing that, at least for some oiled filters, they perform much better than K&N.

And @twX, they do offer a much finer pre-filter for finer dust that requires periodic cleaning. Unless UOAs show concern for that, it seems like a PITB for small improvements.

 

[UG_Passat]

Look at Green Filters. They use a woven cotton media, like a polo shirt

 

[2strokeNorthstar]

We weren't arguing about dry filters, seems we both agree there. Was just sharing that, at least for some oiled filters, they perform much better than K&N.

And @twX, they do offer a much finer pre-filter for finer dust that requires periodic cleaning. Unless UOAs show concern for that, it seems like a PITB for small improvements.

I'm not arguing. S&B are only "better" because they use a couple more layers. I used one for a while, still have it. Build quality is nice.

 

[2strokeNorthstar]

Look at Green Filters. They use a woven cotton media, like a polo shirt

Better than that super static material they use for sport shirts these days.

 

[LDB]

They are all the best. Just read their own literature and you'll see they are. I don't have one so it doesn't matter but they're probably all better and also all worse than advertised and believed, depending on whose information one is consuming.

 

[ZeeOSix]

It's unclear whether S&B is quoting initial, average, or final efficiency, but I'd guess it's the latter since it's better for marketing.

You would need to look at ISO 5011, which should call out how the efficiency is reported.

Same goes with the other measurements - ISO 5011 defines how the test is setup and ran, and how and what test results are reported. That's why ISO test standards exist for oil and air filters, so some standards can be followed to try and get decent apples to apples performance comparisons.

 

[OVERKILL]

I have the S&B intake with oiled filter, and there had been some comments that it was a "rock catcher". I found this while searching for a replacement element, I'm at about 45k on the filter but there is no visible discoloration or accumulation of debris. Says the factory and the dry replacement options are only 0.4% more efficient than their oiled option... way better than K&N! Attachment is a PDF from S&B's website; very thorough and shows ISO testing methods and their comparisons to stock element.

Hmmm, according to this, ISO 5011 uses 350cfm:

ISO5011 air filter comparison

A comprehensive comparison of Duramax paper, foam and cotton air filters tested to ISO5011

www.project200.com.au

 

[SubieRubyRoo]

Hmmm, according to this, ISO 5011 uses 350cfm:

ISO5011 air filter comparison

A comprehensive comparison of Duramax paper, foam and cotton air filters tested to ISO5011

www.project200.com.au

Wow, that article had a ton of awesome info! But, was your reference to the 350cfm to illustrate that the S&B test used higher flow? And that this knowledge of ISO 5011 makes one wonder what the filter performance is at double the test cfm? Just trying to clarify, been a long weekend

 

[OVERKILL]

Wow, that article had a ton of awesome info! But, was your reference to the 350cfm to illustrate that the S&B test used higher flow? And that this knowledge of ISO 5011 makes one wonder what the filter performance is at double the test cfm? Just trying to clarify, been a long weekend

Yeah, it seemed S&B was using a higher flow than the test calls for, which has me questioning their use/claims of SAE 5011, unless there are provisions in the sequence to run it at a different test volume, but I wouldn't expect that to be the case because the entire test is standardized.

 

[SubieRubyRoo]

Yeah, it seemed S&B was using a higher flow than the test calls for, which has me questioning their use/claims of SAE 5011, unless there are provisions in the sequence to run it at a different test volume, but I wouldn't expect that to be the case because the entire test is standardized.

Maybe they mixed their “max flow test” data with the 5011 results. If I’m bored this week I’ll try to give them a call and ask.

 

[twX]

You would need to look at ISO 5011, which should call out how the efficiency is reported.

Same goes with the other measurements - ISO 5011 defines how the test is setup and ran, and how and what test results are reported. That's why ISO test standards exist for oil and air filters, so some standards can be followed to try and get decent apples to apples performance comparisons.

I've only found an incomplete preview of the ISO 5011 standard, but it seems that the manufacturer has the freedom to define the rated flow rate of the air cleaner, and the test flow rate is allowed to be lower than the rated flow rate. They can use either ISO Fine or ISO Coarse test dust, and there are three different efficiency tests defined in the standard: initial efficiency, incremental efficiency, and full-life efficiency. It's not clear from the document I have, but they may be able to arbitrarily define the terminating differential pressure as well, which would affect both the efficiency and dirt holding capacity.

So there are many ways that a filter manufacturer could game the test conditions to maximize the filter's tested efficiency.

Here's a snippet from the standard:

 

[dnewton3]

Well, that kind of makes the test not so "standardized" and therefore just about useless. To be useful, each maker would have to state the specific parameters they chose to use for testing AND then you'd have to get lucky that two or more makers used the same criteria for the tests. Otherwise the compare/contrast is apples to oranges.

 

[RooflessVW]

If the filter isn't dirty...

 

[SubieRubyRoo]

If the filter isn't dirty...

It’s not stopping any dirt?

 

[OVERKILL]

Well, that kind of makes the test not so "standardized" and therefore just about useless. To be useful, each maker would have to state the specific parameters they chose to use for testing AND then you'd have to get lucky that two or more makers used the same criteria for the tests. Otherwise the compare/contrast is apples to oranges.

Yeah, that totally torpedoes the standardization and would mean that you can't compare a filter tested by company A to company B because they might have used different parameters?!

 

[ZeeOSix]

I wouldn't say it "totally torpedoes" the whole standardization. Obviously, the "Duramax ISO 5011 Test" was all done on the same test setup/hardware under the same test conditions by the same operator(s), so that's a pretty good apples-to-apples comparison there.

As far as comparing different company efficiency claims, the main thing you need to know is if the test was done with the "ISO Fine Dust" or the "ISO Coarse Dust" - see attachment below for the specs on the two test dust options. Most will not divulge that info unless you contact the manufacturer. For instance, I contacted Fram about the Ultra air filter and asked them which test dust was used in the ISO 5011 test and was told it was the fine dust (link below to my post).

Air Filter Options for 4.0L V6 Toyota

Looking to replace the air filter on my 2005 Tacoma with 4.0L V6 (1GR-FE engine). I usually go with OEM, but wondering if anyone has found a good aftermarket filter (like AC Delco, WIX, etc) that fits and filters well. One concern is that it must fit well like the OEM filter. The Toyota dealers...

bobistheoilguy.com

Question is ... if the same filter brand & model was tested in the same test setup under the same test parameters, except that the dust used was the specified coarse instead of fine, how much would the efficiency really change? Only some controlled experimentation would tell.

As far as the three different efficiency tests, I would think most filter testers are reporting the "full life efficiency" since air filters will become more efficient as they load up (oil filters do not, they actually get less efficient when loaded up, as discussed in many threads).

I would think the air flow rate may have some impact on the measured efficiency as that may cause some captured debris "sloughing off", but nobody would know for sure without some controlled experimentation to show how. I'd suspect the design of the media has a big factor there, and filters that test lower efficiency are 1) letting particles through, and 2) probably sloughing off some already captured debris too. Filters that test higher in efficiency are doing 1) and 2) to a lesser degree.

The delta-p across air filters is really very low, only 25-30 inches of H20 (1 PSI) when really loaded near usable capacity, so it may be that air filters really don't slough off much if any already captured debris, and that phenomena is what cause them to become more efficient as the loading increases and the dP increases (without sloughing debris).

Also, keep in mind that ISO 5011 does not determine efficiency by using "particle counters" like ISO 4548-12 does for oil filter testing. ISO 5011 uses the weight of the total amount of test dust used, and compares the amount of the test dust by weight caught in the air filter to determine the overall efficiency of the filter.

Obviously, like any testing there is some room for setup and testing parameters, but the standard is better than nothing. It's an industry standard that's been around over 20 years, just like ISO 4548-12. If it was "that bad" it wouldn't have survived that long IMO.

From ISO 5011:

ISO 5011 Test Dust Specs for "fine" and "course" test dust:

Reporting sheet from ISO 5011 - Automotive Applications:
There are different test methods and reporting sheet for industrial application air filters.