If you want to use a spin-on filter to make you feel better about having filtered oil, that's good. The problem with most of them is the size of the particles they remove. The micron size of a full-flow filter is so large that it only traps the big stuff. The original-equipment canister type filter had a much finer filtration built into the filter because the oil did not have to flow fast enough to supply the bearings with enough oil to keep the engine lubricated. The oil was well-filtered, and then simply drained back into the oil pan. One of the industrial-type filter manufacturers like Wix or Baldwin probably has a spin-on filter that has a 5 micron or smaller element that will actually do some filtering in a bypass application. Using a full-flow filter in a bypass situation makes an engine owner feel good, but it does little, if anything to really filter the oil.
Jerry
