What is micron rating?
A measure of the pore size in the filter media. Expressed as either ‘Nominal’ or ‘Absolute’. Nominal Rating relates to the percentage of particles at a given size that a filter can capture ie. 10 microns at 90% means it will remove 90% of particles 10 microns in size. Absolute refers to the removal of all particles at a given micron size and larger ie. 20 micron absolute means 100% of particles 20 microns or greater will be captured. The lower the micron rating, the greater the efficiency and hence the amount of dirt that is captured. Common oil filter micron rating is approximately 30. (Human hair is approximately 70 microns) When comparing different filter brands micron rating, you need to make sure that the same test procedures have been followed.
