About K&N
K&N Engineering was founded in 1969 by motorcycle racers Ken Johnson and Norm McDonald -- the company name comes from the first letters of their first names. What began as a motorcycle parts shop supporting a K&N factory race team shifted focus after the pair developed the original washable, oiled-cotton-gauze High-Flow Air Filter, a design the company has manufactured continuously ever since. K&N remains headquartered in Riverside, California, where it operates a manufacturing complex spanning roughly 400,000 square feet, with additional facilities in England, the Netherlands, and China supporting a catalog the company says covers more than 12,000 parts for cars, trucks, SUVs, motorcycles, ATVs, and industrial equipment.
The reusable cotton-gauze filter K&N pioneered in 1969 is still the core of its lineup today: drop-in replacement engine air filters, cold air intake systems (introduced in 1992), washable cabin air filters, and oil filters, all built around the idea that a properly maintained filter can outlast the vehicle it's installed on rather than being thrown away every service interval. K&N backs its washable engine air filters and intake systems with a Million Mile Limited Warranty -- among the longest warranty terms offered on any air filtration product sold on Amazon -- and its cotton-gauze media technology has become a recognized standard in the performance parts industry over more than five decades.
Brand website: knfilters.com
What K&N makes
K&N's range runs wider than the products we review. The lines we know best from our own testing are marked with a star:
High-Flow engine air filters
washable oiled-cotton-gauze drop-in replacement filters, made in Riverside, California -- the line featured on RevRated — featured on RevRated
Washable cabin air filters
reusable oiled-cotton-gauze cabin filters on a rigid wire mesh frame -- the line featured on RevRated — featured on RevRated
Cold air intake systems
bolt-on performance intake kits, part of the catalog since 1992
Oil filters
spin-on and cartridge oil filters for gas and diesel engines
Recharger cleaning kits
the cleaner-and-oil kits used to service and re-oil K&N's washable cotton-gauze media
Home air filters
washable HVAC furnace filters using the same reusable cotton media technology
Why we recognized K&N
The RevRated Top Brand recognition isn't paid for and can't be applied for. We award it to the brands whose products consistently stand out in our hands-on category reviews. K&N earned it on the strength of the products below, evaluated the same way every product on this site is: bought, run on real vehicles, and judged on merit.
K&N products we rated highly
K&N 33-2443 High-Flow Engine Air Filter
Four layers of oiled cotton gauze measurably outflow the cellulose and synthetic media in every disposable filter we tested, while still holding particles in the 10 to 20 micron range. The washable, reusable design means one filter can serve the life of the vehicle -- over 100,000 miles of driving that eliminates roughly eight disposable filter purchases -- and it's manufactured in the USA at K&N's own Riverside, California facility, backed by the brand's Million Mile Limited Warranty.
Read the 7 Best Engine Air Filters of 2026 guide →
K&N VF2000 Washable Cabin Air Filter
The same oiled-cotton-gauze technology K&N uses in its engine filters, adapted for the cabin: wash it every 25,000 to 50,000 miles instead of replacing it, and it's the only cabin filter in our roundup backed by a Million Mile Limited Warranty against manufacturing defects. In our testing it produced noticeably less airflow resistance through the HVAC blower than any disposable filter, at every fan speed.
Read the 7 Best Cabin Air Filters of 2026 guide →What earned K&N the recognition
- K&N is one of only two brands to earn a spot in both RevRated's engine air filter and cabin air filter roundups, with the 33-2443 and VF2000 each rated among our top picks in their categories.
- Both featured filters use K&N's washable oiled-cotton-gauze media, the same reusable filtration technology the company pioneered in 1969 and has manufactured continuously since.
- K&N backs its washable engine air filters and cabin air filters with a Million Mile Limited Warranty -- the longest warranty term of any filter brand in either of our roundups, disposable or reusable.
- The 33-2443 engine air filter is made in the USA at K&N's own manufacturing facility in Riverside, California, where the company has been headquartered since its 1969 founding.
- In our testing, K&N's cotton-gauze media produced measurably less airflow restriction than cellulose or synthetic disposable media in both the engine bay and the cabin HVAC system.