Tuesday, Nov 14, 2006 at 10:11
I wwas always sceptical of the K&N claims and when I found the site in the link below I knew why.
"Each test filter was used in the same car, on the same roads for 500
miles. The darker deposits indicate poorer filtration, and lighter ones better filtration. That said, both the cotton gauze type (K&N) and foam filters (Amsoil & Jackson Racing) showed the same levels of filtration. Both performed poorly compared to the fiberous or paper filters (Napa, Baldwin, and Mazda). "
Site Link
Note the owner of the site is a mechanical engineer and has quality assurance credentials.
The K&N fillters were designed for racing where engine rebuilds are common,almost weekly and a high level of airflow is considered more important than a high level of filtration.
As the above site shows, flow and filtration are closely linked.
FollowupID:
464710