Choosing the right K&N filter is based on what you need it for as they come in many different size and shapes. K&N drop-in filters, K&N cone filters, and K&N oval filters fit each application differently and are not universal for each engine. K&N air filters are completely washable and reusable when used on any application and include their million mile warranty. K&N filters are also required to be serviced properly using the K&N cleaning kit to maintain this warranty.
K&N drop-in air filters are for those who need a replacement filter for their factory air box. The factory air box uses a square shaped air filter that is placed in front of the engine, but after the pipe that sucks in the air. K&N filters protect your engine from dirt and debris that is sucked in while driving. These K&N air filters are an exact replica of your factory air filter, but have much better filtration while adding horsepower.
K&N drop-in filters are needed because some of us do not want to keep buying an air filter every time it is dirty. The factory air filters cannot be washed or reused and as many as 10 filters will be gone through during the lifetime of your vehicle. K&N filters never need to be replaced, and can be washed whenever you feel it is too dirty or hindering your engine's performance.
If you have an aftermarket air intake, then you need a K&N cone filters. These K&N filters are cone-shaped to allow easy fitment when installing them. K&N cone filters have a large surface area that can filter more debris while still maintaining the best air flow. The cotton media is the same media used on all of their air filters and can last up to 100,000 miles. K&N filters include attachments that are needed to secure them to your intake pipe.
Since all automotive air intakes use different intake pipe sizes, K&N air filters are available in different diameters to fit there pipes. K&N filters easily slip onto the intake pipe and use a clamp that also makes for easy servicing. Once K&N air filters are dirty, the clamp just needs a few turns from a wrench and it pops right off.
K&N oval filters are universal air filters that also fit a wide variety of custom intakes and other performance parts. These K&N filters are perfect for custom projects in which size is an issue or the user has created his own custom air intake. K&N air filters are also good for engine swaps that are going into smaller vehicles. K&N oval filters are thinner than and not as bulky as cone filters so they take up less room while still providing quality air flow and filtration.
K&N filters are also specific for your motorcycle, ATV and RV. If you need a replacement air filter for any of these, K&N filters are selected by a pre-designed database that has every engine possible. Fitment will never be a problem and installation will be a breeze. The K&N motorcycle air filter is both flashy and performance-based so you are getting the best of both worlds.
K&N air filters also come in universal types that include different angles, shapes and sizes along with quality engine protection. K&N filters perform great on high performance vehicles that operate at high speeds around the racetrack or on the drag strip. K&N universal clamp-on filters can be angled in a direction that you would like to optimize air flow.
You can also use the K&N pre-wraps with any of these K&N air filters. The K&N Drycharger, K&N Precharger and K&N Airforce are filter pre-wraps that protect the K&N filter from dust and small particles that have a chance of getting into the engine. These pre-wraps are mainly for those people who drive in high dust areas with warm weather like the desert.