Comment by trenchpilgrim
2 days ago
I began noticing this about seven or eight years ago when the oil filters I bought changed from official ones to obvious counterfeits (certain pieces were missing entirely + media was much thinner than the real ones). Had to switch to a local auto parts supplier to guarantee the correct part.
How did you notice that the media was thinner? On passenger vehicles at least, the filter media is in a stainless steel cup that precludes examination.
Not always - some passenger vehicle filters have exposed media. An example GM filter: https://parts.gmc.com/product/acdelco-gm-original-equipment-...
My current car has a traditional steel-can filter. I cut those open after oil changes to inspect for debris.
BMW at least has the media completely exposed. There is no canister like you might find on Honda oil filters. Basically on BMWs the oil filter housing is permanent. I don't think it's a BMW specific thing. Might be a German car thing?
Similar with VAG.
It was a suzuki with a paper filter cartridge you load into a metal cylinder that is part of the engine. So you can see and feel the media.
Toyota Tundra filters (at least) are the ‘innie’ pieces, and the cup is a removable/reusable part on the vehicle. A counterfeit would be pretty obvious unless it was at the microscopic level.