[GO FURTHER]

Some common questions answered by K. & N. Filters;

Will a K&N filter cause my vehicle's mass air sensor to fail?

No. This is an “urban myth” and has not been supported by any factual evidence. The oil does not come off of a K&N air filter when it is in use, even when over-oiled or in extreme air flow rates exceeding 1000 CF’M.

If somehow K&N air filter oil were to make contact with a mass air sensor, the oil would not cause the sensor to fail. We have intentionally coated mass air sensors with our filter oil, and monitored the sensors’ output when installed in daily driven vehicles. These sensors continued to function normally, even after being sprayed and submerged in K&N air filter oil. K&N air filter oil does not cause problems with mass air sensors.

More airflow means you are letting more dirt through, right?

No, not at all. K&N air filters operate using a much different technology than other types of air filters. Most disposable filters are "barrier filters". That is, their filtering media acts as a physical barrier to dust particles, and once a dust particle covers a pore in the media, air can no longer flow through that space. This principle is called "surface loading". K&N air filters are built using a fabric filtering material which absorbs dirt and dust particles instead of physically blocking them. This is a principle called "depth loading". The pores in the material continue to let air flow through as the filter absorbs dirt in the media.

What is the micron rating and efficiency of a K&N air filter?

Automotive air filters are not rated by micron size, they are rated by efficiency. K&N tests the filtering ability of our air filters using the ISO 5011 test procedure. In general, most K&N air filters will test between 97%-99%
efficiency.

Can a K&N filter give my engine too much air flow?

No, an engine can only draw in a certain volume of air depending on the engine’s bore and stroke, and number of cylinders. A replacement air filter or performance intake system cannot physically increase the volume of air the engine takes in.

How will a K&N filter affect my vehicle's fuel economy?

K&N does not make any claims or advertisements regarding fuel economy.

What increase in horsepower should I expect from a K&N replacement filter?

K&N does not complete vehicle performance tests (dynamometer tests) for every application we build a replacement air filter for. We do complete air flow testing for every air filter, and can verify that a K&N air filter will flow air with less restriction than its OEM counterpart. However, other components of the vehicle’s air intake system (like the air filter housing or tubing) can create air restriction and limit horsepower. The design of these parts varies among different vehicles and manufacturers, so there is no way to estimate a certain amount of horsepower gain from just replacing an air filter. The higher air flow and lower restriction will increase performance, but we cannot guarantee a certain/exact amount.