Every gas-powered vehicle comes with an oil filter, right? So why do some truck owners install second "bypass" oil filters?

See All 14 Photos Bypass Filtration 101:Things You Need To Know Absolute Micron Rating:The smallest particle of which a filter can catch nearly 100 percent of (typically above about 98.5 percent ...

A bypass valve prevents the unit from plugging ... Absolute Micron Rating: The smallest particle size a filter can catch. Micron: Micrometer, which equals one millionth of a meter, or 0.00003937 ...