Selecting a aftermarket air filter is a process of weighing filtration and air flow.  Each type of air filter offers different advantages.

3 Types of Air Filters:  There are three types of air filters, Paper, Gauze and Foam.  Your vehicle generally comes from the factory with a paper air filter.

Paper Air Filters:  Filters made of paper offer filtration and air flow.  They are generally cheaper but have to be replace every 5,000 to 10,000 miles. 

Gauze Air Filters:  Gauze style air filters offer filtration and air flow.  There are 2 types.  Oil based and dry gauze filters.  The biggest advantage of a gauze style air filter is they are designed to last the life of our vehicle.  However, this requires you to regularly clean the air filter with the manufacturers recommended air filter cleaning kit.  Oil based gauze filters tend to filter better then dry but have to be oiled.  Whereas dry gauze filters don’t need to be oiled but the filtration generally isn’t the best.  Each air filter manufacture makes their gauze filters differently.  Most have between 4 and 7 layers of gauze depending on the brand and style of filter.

Foam Air Filters:  Foam air filters is gaining in popularity and offer both filtration and air flow.  Foam filters are very successful in dirt track racing because of their ability to catch the dirt but not loose the air flow.  These foam style air filters are designed to last the life of your vehicle, provided you follow the manufacturers cleaning instructions.  These filters need to be oiled, just like oil based gauze filters.