Every K&N performance part comes with the best warranty in the industry. K&N air filters come with a million mile warranty which guarantees the filter for the life of your vehicle. The cotton media that the air filters are made from will never tear or break during operation and are very easy to clean. The K&N Million Mile warranty is only guaranteed is the product is service properly according to the company's standards.
The K&N Warranty for air filters gives the owners peace of mind when they are using them. Other automotive air filters cannot guarantee themselves because they aren't washable and reusable. K&N filters can be washed over and over again and it will not perform any differently.
If the user were to clean the K&N air filter with anything but the K&N cleaning kit, this would void the warranty. When a defect does occur to your performance air filter, K&N will ask to see it and they can tell right off the bat if it is due to improper servicing. The K&N cleaning kit is very inexpensive for what it does and will save you lots of money in the long run.
Once you receive your K&N performance auto part, you should register it so you can receive the proper warranty, as long as you bought it from a certified retailer or the company itself. This will ensure that you have a legitimate K&N product and not a knock-off. Any modifications done to the K&N air intake or K&N filter will also result in a voided warranty.