The oil filter is a part of the oiling system on an internal combustion engine. The filter takes dirty oil and removes particulates and metal flakes from the oil. The cleaned oil is recirculated through the engine after leaving the filter.
There are two types of oil filters commonly in use. The first is a metal, one-piece canister filter that is removed and installed as one piece. The second is a canister that uses a removable filter element. In the latter, the filter snaps into a cap that is screwed into the oil-filter housing.
The oil filter features a paper filter element with a bypass valve that controls when oil may enter the filter.
In combination with high-quality oil, a good oil filter can help your extend service intervals on your vehicle by keeping the motor oil cleaner for a longer period of time.
Although a variety of oil filters may fit a particular vehicle application, going with the least expensive is not always the best choice. As Automedia notes, a filter is not the right one "just because [it] looks right or screws onto an engine"
If an oil filter gets clogged, it will stop filtering oil altogether, forcing dirty oil to bypass the filter and be recirculated through the engine. In order to avoid this, change your engine oil and filter at the service intervals recommended by your manufacturer.
