The motor oil that you put into your engine, along with its additives, works to absorb and hold organic and inorganic contaminants. Organic contaminants can include bacteria, bugs, and oxidized oil. Inorganic impurities can include metallic particles, wearing off the components of the engine, and dust. Thus, motor oil helps to helps to protect the engine, and improve its efficiency and performance. However, to prolong the life of your engine and provide better performance, car manufacturers also install oil filters that clean the oil before directing it to vital moving parts of the engine.
Types of filter media
Oil filters have different media, or membranes, inside them that filter out and clear the contaminants of the motor oil as it circulates.
Cellulose filter media: Typically, disposable oil filters have cellulose filter media. This media can hold back particles 8 to 10 microns in size and can clean up to 40% of the motor oil. It is advisable to have your mechanic check/replace them at every 3,000 miles.
Synthetic filter media: Higher quality oil filters use synthetic media. This media is effective in removing 50% of the particles in sizes ranging from 20 to 40 microns, and 24% of particles in the 8 to 10 micron range. These oil filters should be checked/replaced every 5,000 to 7,000 miles.
Microglass filter media: Most high-end oil filters include an extremely fine metal media or microglass. This microglass mesh is made with fibers that are 10 times finer than cellulose fibers. They also present far less of a restriction to the flow of motor oil and only need to be checked/replaced ever 2 to 5 years or 10,000 miles (whichever comes first).
Types of oil filters
There is a wide range of oil filters in the market and the type of engine in your car; its size and manufacturing company dictate the kind of oil filter it uses.
Primary oil filters: Most car engine manufacturers install primary oil filters. These oil filters, also known as full flow filters, filter 100% of the motor oil. Since it is essential for these oil filters to work efficiently in order to keep the engine lubricated, they have lower flow restrictions. In colder temperatures, motor oil thickens, and a restrictive oil filter can result in damage to the engine. Thus, primary oil filters allow smaller particles of contaminants to pass through them. Manufacturers also install a fail-safe bypass valve in case the membrane of the filter becomes too clogged. If the filter becomes clogged and does not allow motor oil to reach the engine, a specific pressure system will redirect the motor oil around the membrane to the engine so it continues to lubricate it.
Secondary oil filters: In addition to the primary oil filters, some manufacturers also install secondary oil filters. These oil filters work on a small portion or about 1% to 10% of the motor oil and clean it before routing it back to the engine. They work independently of the primary oil filters and help by removing additional contaminants. As a result, you need to replace the motor oil less frequently. Even if your vehicle does not have a secondary oil filter, you can choose to install one after purchase. These oil filters are also called bypass filters. However, it is important to remember that they are completely distinct from the bypass valve.
Conventional oil filters: These oil filters are a form of secondary filters and use basic cellulose membranes. Since they filter out smaller contaminants, they need replacing more frequently.
Thermal chamber oil filters: These oil filters work in two ways. They filter the motor oil to remove impurities and in addition, raise its temperature so that certain contaminants in the motor oil burn off or get destroyed. In a way, these oil filters work to refine the oil, but to do so, they need to consume electricity. This is why they can reduce the fuel efficiency of your car.
Spinner filters: Also called centrifugal oil filters, these filters use a spinning motion to trap and hold motor oil contaminants. Typically, these oil filters have two sections, a housing chamber and membrane. When the media gets clogged, you only need to replace it while the housing chamber remains usable. The base gasket is an important component of a spinner filter. It works to prevent motor oil from leaking, but is not very durable. If your car uses a spinner filter, have your mechanic check the base gasket, at least once every three months or 3,000 miles.
Magnetic oil filters: These oil filters work to remove the metallic impurities from the motor oil and are ineffective on dust. You do not need to replace this oil filter; simply cleaning it periodically should keep it functional.
Keep in mind
It is always advisable to use the oil filter that your Original Equipment Manufacturer (OEM) recommends. Also, follow the instructions carefully on the frequency of oil filter maintenance or replacement. These instructions are typically based on the conditions in which you regularly drive and the mileage.
If you drive in dusty conditions very often, you might want to have your oil filter checked more frequently.
This article originally appeared on YourMechanic.com as Understanding the Different Types of Oil Filters and was authored by Saroj Aggarwal.