K&N Engineering, Inc. (also known simply as "K&N") is a manufacturer of air filters, cold air intake systems, oil filters, performance parts, and other related products. K&N manufactures over 12,000 parts for various makes and models of cars, trucks, SUVs, motorcycles, ATVs, industrial applications and more. Founded in 1969, K&N is headquartered in Riverside, California, in a complex of 10 buildings comprising nearly 400,000 square feet. K&N also operates facilities in England, the Netherlands, and China. K&N is owned by Goldman Sachs.
K&N was founded by Ken Johnson and Norm McDonald in 1963. The name K&N came from the first letters in the founders' first names. Johnson and McDonald sold motorcycles and motorcycle parts and supported a K&N factory race team. Air filters soon became the primary focus of the company. In the late 1980s, K&N introduced a bolt-on air intake kit to replace the factory air box and air filter. K&N also released a line of oil filters with a stamped hex to accept a standard wrench for installation and removal. K&N has maintained very active involvement in racing and motorsports throughout its history, including the NASCAR Pro Series East and West, and the King of the West 410 Sprint Car Series.
K&N's claims for their air filters have been the subject of some controversy, with 3rd-party tests finding that K&N's oiled cotton gauze filters are less efficient and let more dirt into the engine than original-equipment paper filters, and that they become increasingly restrictive as they are coated with particulates. (air filters in general become more airflow-restrictive as they collect contaminants, but efficiency typically increases for the majority of a filter’s service life.)
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