What is the efficiency rating and at what micron size?

What is the recommended change interval?
August 17, 2018
What function does the wire-backed media provide?
August 17, 2018

The efficiency of a filter is described in terms of a percentage of particles caught at a certain particle size(and larger). Using the ISO 4548-12 multi-pass filtration efficiency test, Royal Purple filters are:

-99% at 25 micron and larger

-98.7% at 20 micron and larger

-80% at 10 micron and larger