What an oil filter actually does
An oil filter strains grit from engine oil before that oil recirculates. Spin-on or cartridge. A bypass valve exists. It is not the air filter, and the interval still matters.
The myth is that this can is a coffee filter you can ignore — or that it is the paper brick in the air box. What it actually does is strain oil after the pump, before that oil goes back through the bearings.
Spin-on or cartridge. Same job. Oil comes in around the media and leaves through the center. A bypass valve sits in the can. Cold thick oil, or a clogged pack, and that valve opens so the engine still gets oil — dirty rather than none.
It is not the air filter. That one is intake air. This one is the oil circuit. Interval matters because the media loads up. Skip the change and the bypass starts living open. The replacement can on the counter is the same part as the one on the block.
