There has been a long standing debate out there on whether the Challenger and similar filters are any good.
This is one old report. Here is a more recent one. Predictably this is mostly from the US, due to their much larger owner community.
The general drift is that the reusable (stainless steel filter element) filters are much worse than the disposable (paper) ones. The seem to have test results to support this. However the guy who did the recent test is not disclosing some of the data because of who commissioned the test – AIUI.
However, there is no data supporting a longer engine life. I wrote to Camguard (who should have tons of data) and their reply was
In our experience, most oil filters do a good job keeping insolubles (oxidized solids from heat, use, and blow-by) out of circulation. As
long as they don’t exceed 0.6% in oil analysis, the oil filter did a good job.
Based on our tests, we haven’t found any oil filters that are better or worse than others, and the metals we test for are too small to filter, so the oil filter itself doesn’t usually have a big impact on wear levels. Feel free to use any filter you’d like. I won’t be surprised if the cheaper filters do a good job like more expensive options.
The same is true for reusable and disposable filters – we don’t see a significant difference in insolubles so both types of filters are good options.
I think if the paper filters were as much better as the test data suggests, this would translate into dramatic variations in engine life. These would also show up in oil analysis because that is what engine wear is: metals in the oil.
First, the test results were not unexpected… a quick glance comparing a paper vs reusable filter is enough, no need for expensive laboratory testing.
What the testing revealed is that some of the automobile filters provide better filtration (and price…) than their aviation counterparts.
this would translate into dramatic variations in engine life
As long as the in suspension particles don’t break the oil film, there shouldn’t be friction nor contact, therefore no different wear. Old engines equipped with screens or no filter at all did not exhibit more wear, if at all.
As we know, about 80% of the wear in an engine occurs during engine starts, the colder the worst.
Peter wrote:
I think if the paper filters were as much better as the test data suggests, this would translate into dramatic variations in engine life.
well, let’s just say that paper oil filters have been mostly phased out in professional applications and synthetics are commonly used. The reason being superior micro particle filtration. Having said that, we’ve seen well documented examples of Lycoming O360 exceeding 5k hours of reliable service operating on leaded fuel + mineral oils + paper filters
I think the most telling thing is that the oil analysis doesn’t seem to change.
How does one explain that?
the most telling thing is that the oil analysis doesn’t seem to change
I will not try to explain it, but rather reinforce that by showing (hopefully legible here) part of my before and after life with a S15 installed, oil analysis courtesy of AOA
Looks like almost everybody is sticking with the old screw-on disposable filters.
Well, they work, are mentally simple, but are a bastard to cut open and inspect.
Peter wrote:
but are a bastard to cut open and inspect
Search the web for “oil filter cutter”… Makes it trivial.
I have the Airwolf cutter. It is ok but messy.
I liked that Tempest oil filters had a magnet, so the worst (steel) metal particles would stick on it and were easy to inspect. Sadly they no longer have them since covid started and the supply chain issues started. They haven’t brought them back yet.
