How Often to Change Engine Air Filter
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The Different Types of Engine Air Filters and How They Work 

Your engine is like the heart of your car. And just like your heart, it needs clean air to work well. That's where the air filter comes in. It's the first line of defense against airborne contaminants, protecting the engine while allowing the right amount of air to flow through. In this article, we will look at the different types of engine air filters. 

Common Types of Engine Air Filters 

Engine air filters can be of different shapes and made of different materials. There are flat (panel-like), conical, round, or radial air filters, with flexible or rigid frames. Similarly, based on the filter media employed—responsible for capturing contaminants—there are paper, foam, synthetic filters. Here's a quick overview: 


FRAM Flexible Panel Air FiltersFlexible Panel Air Filters: These are the most used types of engine air filters. Flex panel filters are enclosed in a soft frame usually made from a type of polyurethane which gives them flexibility. While this makes them easier to install and remove, it does mean the frame can be damaged through rough handling. As with any engine air filter, proper installation is key to consistent performance. Any frame damage can lead air bypassing the filter and allowing contaminants through which can impact engine performance.



FRAM Rigid Panel Air FiltersRigid Panel Air Filters: With a solid frame made of rigid plastic, these filters maintain consistent shape and performance. However, because of their rigidity, a separate gasket is required in many cases to ensure proper sealing, whereas a flex panel filter does not. Rigid panel filters use a synthetic media allowing for consistent performance and durability. 



FRAM Conical Air Filters Conical Air Filters: You will see conical filters much less frequently than flexible or rigid panel filters. Conical filters were used in select truck applications in the past and were so named because of their cone-like shape. In terms of performance they are similar to flex panel filters, using similar media and polyurethane compounds. Installing a conical air filter can be trickier than a standard panel filter because the cone has to sit just right in the housing to ensure air cannot bypass. Proper installation is essential for durability and performance.



FRAM Round Air FiltersRound Air Filters: Round air filters are often found in classic cars. These filters provide standard filtration using various paper types. The round shape aids in the even distribution of air, helping the engine breathe more efficiently, although not necessarily optimizing the airflow to the degree that more advanced filters might. 



FRAM Radial Seal Air FiltersRadial Seal Air Filters: Radial seal air filters employ a unique sealing mechanism that is more efficient at blocking airborne particles from bypassing the filter and entering the engine. They're usually found in heavy-duty applications like trucks and industrial vehicles, where a superior seal is beneficial to handle demanding environments. 




Paper (Cellulose) Filters: These filters are made of cellulose fibers. Cellulose fibers are quite dense, so they provide good airflow and a solid level of filtration against dust and debris. Paper filters are generally the most affordable and common type of engine air filter.

Foam Filters: These filters are known for their lightweight and porous structure. They have increased filtration capacity against fine particles, which is beneficial in dusty environments. Foam filters are often used in off-road vehicles, motorcycles, small engines, and other applications where exposure to dirt and dust is a concern. 

Synthetic or Synthetic Blend Filters: Synthetic filters have increased durability and superior filtration capacity, capturing smaller particles with greater efficiency than standard paper filters. High-quality synthetic filters like FRAM Ultra Premium Air™ can achieve a balance between airflow and filtration efficiency and are typically more resilient to moisture, heat, and chemicals compared to paper filters.

By understanding the properties of each type of engine air filter, you can make a more informed decision about what's best for your vehicle. We recommended consulting FRAM's official website or contacting customer support to determine the compatibility of the engine air filter for your specific vehicle make, model, and year.

Questions? We're here to help. Reach out the FRAM specialists for product and maintenance support.


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