KITPLANES Magazine Oil Filter Testing May 2025 - Reuseable Screen Oil Filters Are Ineffective

[1980Mooney]

Great oil filter analysis conducted by KITPLANES Magizine.  It shows that the reusable screen oil filters by Challenger and K&P are shockingly ineffective and cumulatively blind much more easily than traditional disposable pleated filters.

• Challenger claims 22 microns and K&P claims 35 microns effective removal however neither removed even 1% of particles in the 20-40 micron range.
• Examination by mesh calibration labs of the stainless-steel wire cloth in both screen filters showed that it is recognized as having only a 60 micron effective removal range within the process industry.
• The results show that they stop only the largest particles and that they blind off more easily

In terms of effectiveness, they remind me of the old oil screens in the vintage VW air cooled Beetle engines.

Oil Filter Testing - KITPLANES

Edited May 30 by 1980Mooney

[1980Mooney]

34 minutes ago, lithium366 said:

These claims aside, I have a dumb question: with older airplanes having only oil screen, does fine particles oil filtering even have a noticeable impact on wear till (and past) TBO and will impact parts limits at overhaul?

Carbon particulates from combustion byproducts in oil can be very abrasive especially as they clump together. 

[lithium366]

24 minutes ago, 1980Mooney said:

Carbon particulates from combustion byproducts in oil can be very abrasive especially as they clump together. 

I have very little knowledge of what testing is done by FAA for STC but I am surprised and disappointed that K&P filters were never tested for their claims independently since they were used in cars for a while now, and also by FAA

 

update: looks like some testing was done https://www.motor1.com/news/736893/metal-oil-filter-comparison-test/#:~:text=The results are decisive,Yikes

 

https://bobistheoilguy.com/forums/threads/particle-count-comparisons-fram-ultra-vs-k-p-reusable-stainless-mesh-oil-filter.376224/#:~:text=Looks like below 20u the,must be ultra fine screen

Edited May 31 by lithium366

[Paul Thomas]

If you want to geek out, Van's Air Force forums, had a thread about it when the results came out.

[0TreeLemur]

Very interesting.  It seems that Wix is head-and-shoulders above the rest at total capture.   Larger particles are more likely to do damage.  I'd like to know what is the particle size where removal is a) most beneficial and b) essential for engine longevity?