An
oil filter is a
filter designed to remove contaminants from
engine oil,
transmission oil, lubricating oil, or
hydraulic oil. Oil filters are used in many different types of
hydraulic machinery. A chief use of the oil filter is in
internal-combustion engines in on- and off-road
motor vehicles, light
aircraft, and various
naval vessels. Other vehicle hydraulic systems, such as those in
automatic transmissions and
power steering, are often equipped with an oil filter.
Gas turbine engines, such as those on jet aircraft, also require the use of oil filters. Aside from these uses, oil production, transport, and recycling facilities also employ filters in the manufacturing process.