K&N cannot comment on tests conducted by this person since we have no way to
confirm or validate his statements about how he performed them (or if in
fact he did).
We can only tell you our findings when we had our filters tested.
Our filters are tested by an outside, independent laboratory. They have
been proven to stop at least 99% of particles on a SAE dust test. This test
uses particles as low as the 0 - 5 micron range and goes up to 20 microns.
For comparison, a paper filter also stops 99% on the same test and the OEM
minimum standard is 96%. Foam is generally the worst media with a typical
efficiency rating of 75 - 85%.
The testing procedure used is SAE J-726 using ISO Test Dust. This test is
the standard of the air filter industry. The test procedure consists of
flowing air through the filter at a constant rate (airflow rate is
determined by the application) while feeding test dust into the air stream
at a rate of 1 gram per cubic meter of air. Links to the filtration tests
are on our web site at http://www.knfilters.com/images/factstab1.gif
As the filter loads with dust the pressure drop across the filter is
increased to maintain the prescribed airflow rate. The test is continued
until the pressure drop increases 10" H2O above the initial restriction of
the clean element (in this case .78" to 10.78" H2O). At this point the test
is terminated. The dirty filter element is then weighed. This weight is
compared to the clean element weight to determine the total Dust Capacity.
The amount of dust retained by the filter is divided by the total amount of
dust fed during the test to determine the Cumulative Efficiency.
The K&N filter achieved the following results:
Dust Capacity: 305 grams
K&N Cumulative Efficiency: 99.05 %
K&N Initial Pass Efficiency: 97.11 %
OEM Paper Cumulative: 99.29 %
OEM Paper Initial Pass: 96.47 %
Holding the filter to the light is useless, pin holes are normal. That is
what makes a K&N filter. There are actually dozens of microscopic fibers
that cross these holes that when treated with oil become somewhat
transparent but still capture and hold the very fine particles. Spray WD-40
on a piece of paper and it will be transparent too. On the same hand, they
allow the filter to flow more air than paper or foam. The filter is 4 ply
cotton gauze unlike some competitors synthetic material filters. The
synthetics do not have the very small fibers that natural cotton does.
Also, the oil can be pulled off of a foam filter contaminating electronic
sensors. It will absorb into cotton and stay in the media.
We got started over 30 years ago making filters for motorcycles and off road
racers. The filters did so well that these guys wanted them for their cars
and trucks. We started making filters for these applications and here we
are today. If they did not work, we would not still be here and growing
We now make filters for Chrysler/Mopar, Ford Motorsports, Edelbrock, Rotax
Engines, and Harley Davidson. We come as original equipment on the 2000
Ford Mustang Cobra-R. We even made filters for the Apache helicopters used
in Desert Storm because of maintenance problems with the original paper
design. Now we are on the new unmanned Predator plane being used in
I hope this answers any question you have about our filters ability to
K&N Engineering, Inc.
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