filter is made from paper or other media to trap dirt and
other foreign particles as dirty air passes through the filter.
There are tiny holes in the media that allow the air to pass
through and these holes stop most particles.
Air filters are not 100 percent
efficient at trapping dirt particles. Most new air filters
are 97-99.9 percent efficient. A small amount of dust or dirt
can pass into the engine. As the air filter builds a dust
film, the holes in the media become smaller, and the filter
becomes more efficient at trapping dirt.
As the filter traps dirt, it is
more difficult for the air to pass through the filter, and
restriction increases in the air induction system.
The Filter Minder®
measures restriction or vacuum. The air filter service indicator
is calibrated per engine or vehicle manufacturer’s recommendations.
The air filter should be serviced
when the position indicator of the service indicator approaches
or reaches the red zone.
Use of the Filter Minder®
helps maximize filter service life, prevents excess fuel usage
from overly restricted filters, and saves on operational costs.