Interesting Information about K&N Filters

[rsimoes]

I asked them if their filter allow more dirt along with more air and this is what I got back:

Dear Rob,

Our filters, filter as good or better than paper while still increasing the air flow. 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%. To get higher ratings, the foam must be more dense and therefore way more restrictive. The "tack" characteristic of a K&N allows for increase filtration without loss of flow as well.

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.

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 every year.

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 Afghanistan. If they work in these conditions they will work for you. Links to the filtration tests are on our web site at http://www.knfilters.com/images/factstab1.gif and http://www.knfilters.com/images/factstab2.gif

Thanks for writing, Fred