Attached is a link to a major test of air filter types, using expensive, state of the art testing equipment.  The reason this type of testing equipment is necessary is because the human eye cannot determine how much dirt passed into your engine's cylinder, by just looking.  Dirt may get sucked into a cylinder without leaving a trail on a filter or inside a carburetor.  

http://duramax-diesel.com/spicer/index.htm

The report is long but well worth reading.  It shows that NOTHING filters air as well as a paper filter.  K&N's cotton gauze is one of the least effective, as you will see.

Although not mentioned in the test results, it is important to remember that paper air filters cannot be cleaned and re-used, due to their filtering the sticky petroleum contaminants found in exhaust fumes and industrial airborne pollution.  The solutions needed to wash these contaminants out would destroy the paper filter.

 The link you provided consists of a link quoting part of the of the link I initially posted, and the opinions of other posters.  Unless I'm missing something, what data is in your link to support your suggesting that that the comprehensive testing that was done, is exaggerated, concerning K&N?

Sorry, but I don't agree with your interpretation or suggestion that this major test is biased against oiled filters.  The Testand Corp engineers who did these tests clearly know exactly what they are doing and wouldn't risk their company's reputation in the field by publishing  info that could be so easily disproved or attacked; especially by those not trained in the subject; and it would make no sense if one were to suspect that this test had hidden agendas.  Testand has nothing to gain by being deceitful or biased.  Furthermore, K&N has been tested a number of times in less definitive tests, and every one I've seen on the Internet shows sub-standard results for K&N, its clones and of course foam filters.  Anyone who wants to spend the time can also search the net for these less thorough test results.

Despite all this, I myself use a cheap cone style cotton gauze filter oiled with KN oil, which probably lets everything pass through it except for rocks.  But it sure sounds nice to hear the intake howl as it sucks in air.

You said the tests are biased, and that suggests deceit.  Do you suppose the testing engineers would be unaware that their tests were biased?  And if they were aware, it would have been deceitful of them to knowingly present biased results as fact.  No 'strawmen' here.

How do you know that oil is "blown off" the filter? Do you think KN and other oiled filter designers would design filters which; when used according to instructions; allowed oil to be vacuumed into your engine, and risk having the public find this out?  How do you know that oil and dust are condensed and passed through the filter? Your argument that the oil leaves the filter because you can smell it, is invalid without supporting data.  Filter oil is made up of various chemistries, so if you are smelling something, it may be a other added chemistry that may be harmless to an engine, and not "airborne oil droplets". The other chemistries may be vaporizing, leaving the oil on the filter.  There is no way for your nose to know what it is smelling, unless you have test data analyzing the vapors, or test data analyzing the chemistry of what the testing equipment collected.  I used to use KN filters on my cars and bikes, and I never saw any evidence of oil in the carb mouth or anywhere else. However, perhaps I did not read the test results I posted carefully enough, so if there are test results describing oil passing through the filter or condensing with dust and passing through, please correct me and you will have my apologies.

As for the less definitive tests on the 'net, you can find them by using your search engine.  The test link I provided was all I saved because it is the most definitive there is.  

Foam filters are used on off-road vehicles because any filter will clog  quickly when off roading in dusty areas.  I've done a great deal of off roading and the reason for the foam filters is because when you stop for a break, you can quickly remove the clogged foam filter, wash it with the water and detergent or bar of soap you brought along,  ring it out and oil soak it again.  I've had to do this several times a day, off roading in the desert.  If you also use that vehicle for street use, you then remove the foam filter and re install the factory unit.  The foam unit is a compromise for that very reason.  It does not filter as well as a paper unit, but unless you want to bring along a box of spare filters, you must use the washable foam unit.

I did not suggest that KN and foam filters are "crap".  

"Naw, it's valid.  Anything that you smell off a filter is a collection of molecules that have evaporated off of it and gone up your nose. As far as the public perception of oil going into the engine (ruined sensors and whatnot) the filter manufacturer can always claim over-oiling. They probably formulate the oil sticky enough so that it would take a severe over-oiling to foul any sensors."

Wrong.  What you smell may not be a complete collection of molecules.  Depending on the product, it may be a partial collection.  Case in point:  Safety Kleen Corp. leases an aqueous parts washing machine, which contains an 'open to the atmosphere', mix of heated water and surfactant chemistry.  The water evaporates out of the machine into the atmosphere, but the surfactant chemistry does not.  It stays behind, and the businesses that use the unit are told to simply add more water when the level is low as a result of evaporation.  Some molecules will stay behind in some circumstances and this may be exactly what is happening to the chemistry on an oiled filter, until you run the tests needed to determine that.  

You state that they "Probably formulate the oil sticky enough so that it would take a severe over oiling to foul any sensors".  Again, you are guessing thats what they do.  You don't know for sure what they do and therefore cannot use a guess to validate any of your conclusions.






"It's possible they didn't consider the oil, as the test is primarily for automotive and industrial air filters, only a small percentage of which are oiled.  It's possible they know the effect but consider it insignificant. It's possible they pre-blew the filter with filtered air to lessen the effect, or devised some unspecified way to compensate for it. We don't know. All scientific experiments contain SOME amount of bias BTW.  The engineers drew a line somewhere that probably does not affect the vast majority of their tests but I think may be significant for oiled filters on motorcycles."  

It is also possible they did consider the oil.  It is just as possible that they do consider the effect significant. Its is also possible they did not pre blow the filter to lessen the effect, and did not devise some unspecified way to compensate it.  As you said, you "don't know".  You cannot use these arguments to validate your claims because you are guessing what they did.




"For purposes of the test, who cares about the chemical makeup of the molecules that evaporate off the filter? Whether they are the heaviest paraffins, olefins, asphalt, or lower flash point components considered "oils" or the lightest aromatics like butane, they all have mass and therefore don't contribute to the weight of the filter after the test."

You care, because you state that they form droplets and are condensed in the test stations post filter, gets logged as dirt and hurts the dirt retained calculation.



"Your requests for the chemical analysis of the vapors and that the condensed vapors be considered, isolated from the dust and weighed in a lab, are impossible red herrings. I don't need to provide this (likely non-existent) lab data to validate a phenomenon you know darn well is occurring.  I don't expect or want an apology, and I'll understand if it just isn't your style to say "Oh yeah, thanks" when someone points out something you didn't notice at first, but that might refine your thinking on a subject."  

Wrong again.  No one knows "darn well" it is occurring, because you do not know which of the molecules has passed through the filter into the testing machine.  Again, you are guessing.

 If someone wants to disagree with this test data, they need to substantiate their claims with contradicting data.  Without that, disagreement with the data is nothing more than un-supported opinion, and should be stated as such.   "Knowing darn well" means nothing.

My opinion of Oldfeller's filter is off topic.  Why do you keep trying to draw me into that discussion?  If you want to discuss his filter, start a new thread in the "Rubber Side Down" section.