Two types of oil filters are now used:

One is the assembly type and we said filter assembly, the internal structure is generally interwoven steel net together, iron shell combination and external together. The type or part number printed on the iron shell, replacing the need to replace the whole.

Another is the split core type, its exterior is a metal shell protection, installation (usually with iron, aluminum, two) is an internal filter (usually with blankets, paper and metal wire material three). And the inside of the filter shell is separated, the filter can be replaced only the need to replace it.

Oil filter replacement cycle

Oil filter oil, the impurities and dirt in the filter, with various impurities, dirt accumulation, a long time will need to be replaced.  

The replacement of the oil filter is always done at the same time as the oil change