I started to run FilterMags a few years ago after looking how much got caught in the transmission pan!
Iím using a PAIR of FilterMags and more neodymium bar magnets on the empty spaces around the filter
the FilterMags doesnít cover.
Over the years Iíve tried most major brands of oil filters, in each case the engine oil darkened just as quickly.
In vintage cars hi blow-by can allow soot to darken oil. In late model cars, blow-by is a lot less, itís mostly wear metals.
Iím up to 8 months before then engine oil darkens instead of 2 months! The UOA come back with lower metals across the board.
I figure with 50% less iron allowed to circulate in the oil then wear to other parts including lead babbit main bearings drops to.
So far lead is at < 1PPM - meaning ďtrace levelĒ only, kinda nice!
I use a drain plug mag too with a 1Ē long mag built in, but no accumulation on it for the last 3 years. My PPMs overall are fairly low anyway.
Since oil pan steel is .080Ē or thicker, magnets on outside of steel pan have little effect in the oil pan, plus you canít clean off
the inside. The steel shell of a spin-on filter is under .020Ē thick so FilterMags and bar mags work well, when get rid of the filter
you get rid of the metals too!
Since oil filters are specíd around 95% (at 20 microns) all the stuff picked up is way smaller and never gets caught in filter Ė just the magnets.
I tried whatís in this PDF, lots of good pics too:FILTERMAG vs HOMEBREWhttps://app.box.com/s/uxvu8dmscf5wcgftutdm0ejqwgn86tw7