"According to Fram’s Technical Training Manager Jay Buckley, dirt and foreign material measuring smaller than 10 microns will be small enough to be carried in suspension in the oil and will pass through even tight bearing clearances. Material larger than 20 microns is generally considered too large to pass through tight bearing clearances although with performance engines with main bearing clearances of 0.0030-inch, this is certainly possible. But generally speaking, foreign material in the range between 10 and 20 microns will potentially do the most engine damage over time. So a filter that can efficiently filter within this range would offer distinct advantages and certainly reduce engine wear."
http://www.onallcylinders.com/2015/05/29...our-oil-filter/
“Fram Ultra Guard filter, it is 99 percent efficient at 20 microns. At 10 microns it’s 94 percent efficient.”
Very impressive!
For some comparison/context, here's what Royal Purple says about their filters:
99 percent @ 25 microns/80 percent @ 10 microns
http://www.onallcylinders.com/2015/05/29...our-oil-filter/
“Fram Ultra Guard filter, it is 99 percent efficient at 20 microns. At 10 microns it’s 94 percent efficient.”
Very impressive!
For some comparison/context, here's what Royal Purple says about their filters:
99 percent @ 25 microns/80 percent @ 10 microns