Originally Posted by Gokhan
Originally Posted by y_p_w
And reading here there are a lot of people who deliberately choose an "incorrect" filter. Possibly based on the notion that a bigger filter with more media surface area will be bigger. Or a larger can might increase oil capacity. I get the idea that bigger is better, but it seems kind of excessive.
With the spin-on oil filters, if it mechanically fits, including the holes and gasket, there is no such thing as a bigger oil filter being incorrect. Someone posted on BITOG that the oil-pressure setting for the bypass valve in the aftermarket oil filter was smaller than for the ones in tiny Subaru OEM oil filters, hence incorrect, but that's utter nonsense. The pressure for the oil-filter bypass valve is determined by the oil-filter media (type and size), not the engine.
For my engine, Toyota originally used an oil filter about the same size as what I call oversized Fram Ultra XG3600 installed now. Purolator's standard L22821 oil filter for it, now discontinued, was also pretty big. Later, Toyota chose to cut the waste and cost and they have gone with one-size-fits-all tiny 90915-YZZF2 for most of their cars.
The only reason why Subaru uses a tiny oil filter for your engine is to cut the waste and cost. It's not because they are trying to optimize the oil filtration. I encourage you to upgrade to a more efficient and larger if possible aftermarket oil filter.
With cartridge oil filters, the cartridge may be of the incorrect type, such as missing the protrusion piece. That will cause engine damage. See my previous post.
No. Before this Subaru was using a larger oil filter. The OEM version sold in the US was made by Purolator - the one in the white can where I found a photo. They decided on the smaller filter with the same 23 PSI bypass spec. The reason was to give a little more clearance from the exhaust components that literally surround the filter. That smaller filter is actually more expensive. Subaru considered them interchangeable, although the smaller one was preferred for the turbo models. As far as I know, the Wix 57712 is the only aftermarket filter with the 23 PSI spec other than the OE-style aftermarket wholesalers like Beck-Arnley. Wix recommends that small one even though Subaru had a bigger OEM can with the same bypass spec.