Air filters are not measured by micron size. As an industry standard, air filters are tested in accordance with the ISO 5011 test protocol to measure capacity (the physical amount of dust a filter can hold before cleaning is necessary) and efficiency (the filter’s ability to trap and hold dust). See technical service bulletin 89-5R from the Filter Manufacturer's Council. The dust selected for the test contains a specified distribution of different particle sizes according to ISO standards.

Air filters are not rated by micron size on an absolute basis. (See technical service bulletin 89-5R from the Filter Manufacturer's Council) The proper rating system for air filters is a testing procedure developed to measure the efficiency of the filtration media at varying micron sizes. We routinely subject a sample of our air filters to this testing procedure conducted by independent laboratories.

The micron rating of a filter represents the size of particle that the filter can remove from the fluid passing through it. The micron rating should be associated with an efficiency or beta value to indicate how efficient the filter is at removing that size of particle. Any given filter will remove various sizes of particles. The difference between filters is how efficient they are at removing certain sizes of particles.

No. An engine can only draw in a certain volume of air depending on the engine’s size (measured by such things as bore, stroke and number of cylinders). Vehicles are designed to accommodate large changes in air pressure so they can operate at sea level or at an altitude of 14,000 feet. Engine computers adjust the amount of fuel required as a result of changes in air pressure (density).

If you have not experienced a decrease in mileage or engine performance, chances are your filter is fine and does not yet need cleaning. To be more specific, the filter does not require cleaning if you can still see the wire screen on the entire air filter regardless of how dirty it may appear. When the screen is no longer visible some place on the filter, it is time to clean it.

K&N has an active Custom Air Filter Program to meet the needs of consumers with special filtration needs. We offer thousands of possible configurations of custom filters, in different shapes, dimensions and heights. Click here to read more.

Use a K&N Filter Care Service Kit, available at all major auto parts stores and a low pressure nozzle-free garden hose. A filter cleaned with K&N cleaning products will ensure a lifetime of performance from your air filter. Instructions for cleaning your K&N air filter are on our Air Filter Cleaning Instructions page.

K&N direct replacement filters which install into your vehicle’s factory air box can provide an increase of between 1 and 4 horsepower. Results will vary depending on your vehicle, driving habits, load on the engine (towing for example), existing air system restriction, and other factors.

If an existing K&N filter is large enough to provide negligible restriction, a larger than required filter will not affect the amount of air an engine can take in, however, it will lengthen the filter’s service interval. A longer service interval can be an important factor when racing in dusty, dirty environments.

There is a relationship between air filter restriction and mileage. The theory behind this is simple, the harder an engine has to work to suck air through the intake tubes and air filter, the more gas gets wasted in the process. Replacing a dirty or clogged air filter is one of many recommendations the U.S. Department of Transportation suggests for improving fuel economy (see http://www.fueleconomy.gov/feg/FEG2007.pdf).

It is against federal law in the United States for a manufacturer to require the use of a specific brand of air or oil filter unless it provides a replacement air or oil filter, free of charge, under the terms of the vehicle warranty. For a more thorough discussion of this law known as the Magnuson-Moss Warranty Act, see our Vehicle Warranty Section of our Air Filter Facts page, and our Letter Regarding Vehicle Warranty and K&N Replacement Filters.

It is impossible because we know that the oil treatment on our cotton is very small (usually less than 2 ounces). Once the oil is properly and evenly absorbed through the cotton, no oil will come off, even under extreme engine conditions.

A micron rating is a value assigned to a filter, indicating that filters ability to remove a certain size of particle. To accurately determine the filter's ability in removing a certain particle size, Beta Ratios from multi-pass testing should be used.

For best results, we recommend that you use K&N air filter recharging oil and K&N air filter cleaner. K&N air filter oil is a special compound which forms a very efficient tacking agent that helps capture dust. Our cleaner is a non-detergent degreaser. Petroleum products such as transmission fluid and motor oil will soften and destroy the rubber sealing edges. Harsh solvents and gasoline will harden the rubber seals causing the filter to distort (shrink).

According the list members, the proper part number is #33-2111. Be warned the part number #33-2014 fits, but not properly.

It is against the law for a manufacturer to require the use of a specific brand of air filter unless it provides a replacement air filter, free of charge, under the terms of the warranty. For a more thorough discussion of this law known as the Magnuson-Moss Warranty, see our Vehicle Warranty Section of our Air Filter Facts page. Also see our Letter Regarding Vehicle Warranty and K&N Replacement Filters.

A:You can buy the K&N chemicals (cleaner and reoiler) or you can use a detergent called Formula 409 (used for cleaning kitchens in the US) to save some money (the K&N cleaner is rumored to be the same as Formula 409). You should always use their oil though. Also do not rinse the filter in hot water. It'll shrink the cloth.

K&N is an aftermarket manufacturer of air filters for your car. The air filters from K&N provide higher flow (and thus increased power, although maybe not noticeably) of air to your engine. The more air your engine has to use, the more power it will output. You don't necessarily need one for your Grand Prix, but it's not a bad idea.

A measure of the pore size in the filter media. Expressed as either ‘Nominal’ or ‘Absolute’. Nominal Rating relates to the percentage of particles at a given size that a filter can capture ie. 10 microns at 90% means it will remove 90% of particles 10 microns in size. Absolute refers to the removal of all particles at a given micron size and larger ie. 20 micron absolute means 100% of particles 20 microns or greater will be captured.