Oil filter shortage

Two questions somewhat but not really related, buts since there being discussed?

If the bypass rating is 9-15 for example, does that mean it starts opening at 9 and is fully open at 15, or is that just a tolerance / range?

What could possibly be the benefit of a higher pressure bypass? I realize you want to force oil through the media, but wouldn't I rather have lots of unfiltered oil rather than starved for oil? Wouldn't the bypass pressure be a function of the filter media and the ability for oil to flow through it, rather than engine its filtering oil for? I am just trying to understand it all?
 
Two questions somewhat but not really related, buts since there being discussed?

If the bypass rating is 9-15 for example, does that mean it starts opening at 9 and is fully open at 15, or is that just a tolerance / range?

What could possibly be the benefit of a higher pressure bypass? I realize you want to force oil through the media, but wouldn't I rather have lots of unfiltered oil rather than starved for oil? Wouldn't the bypass pressure be a function of the filter media and the ability for oil to flow through it, rather than engine its filtering oil for? I am just trying to understand it all?
Presumably the manufacture was seeing the bypass valve open more than they liked and spec'd it higher thus. I would be very interested to see some sort of Subaru tech-doc on the subject. Mazda says their issue was high pressure spikes due tot he high surface area bearings used.
 
The louvers help create what is known as the Venturi effect allowing for oil to flow through the media at a faster rate. Creating a negative pressure inside the core and the laws of physics happen. Where things of higher pressure migrate to things of lower pressure. And so the theory is better filtered oil at a faster rate.
The oil volume flowing through the filter is the same as the oil volume leaving the PD oil pump as long as the pump isn't in pressure relief, which is a rare occurrence. Louvers don't make an oil filter flow oil volume any faster than that. Actually, if louvers increase the total flow area of the center tube, then the actual flow velocity of the oil volume going through those louver openings is decreased, not increased.
 
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Wouldn't the bypass pressure be a function of the filter media and the ability for oil to flow through it, rather than engine its filtering oil for?
Yes, the filter's bypass setting is a function of the filter's performance as well as the engine it's used on. This is why 10 different oil filters specified for the same engine can have bypass settings that vary quite a bit. Obviously, if an engine's oil pump puts out 15 GPM max vs one that puts out 8 GPM max, then the filter bypass setting should be set higher for the engine with the 15 GPM max oil pump. Also, one oil filter can be specified for many different engines, and if the filter is designed to work correctly on the most demanding engine (ie, highest flow oil pump, uses the thickest oil, etc) out of the group, then it will also work correctly on all the other less demanding engines.
 
Royal Purple filters are out of stock in lots of models as well. Not sure who makes Subaru filters but RP 10-2867 (Honda and others) have been out of stock for over a year with no end in site.
Speak of the devil... this notice was in my inbox when I logged on this morning. The RP 10-2867 is back in stock at Summit Racing. Got get you some!!!

filter back in stock.JPG
 
After calling Wix they said it is the media for the filters they are having a problem acquiring the raw materials for making the filter media, and should be back in full production by February 2023.
 
Yes, the filter's bypass setting is a function of the filter's performance as well as the engine it's used on. This is why 10 different oil filters specified for the same engine can have bypass settings that vary quite a bit. Obviously, if an engine's oil pump puts out 15 GPM max vs one that puts out 8 GPM max, then the filter bypass setting should be set higher for the engine with the 15 GPM max oil pump. Also, one oil filter can be specified for many different engines, and if the filter is designed to work correctly on the most demanding engine (ie, highest flow oil pump, uses the thickest oil, etc) out of the group, then it will also work correctly on all the other less demanding engines.
Great explanation. Thank you. I'm a first time Subaru owner here and have found the focus on oil filter bypass psi by other Subaru owners unique, confusing, and I privately wondered if it was totally unnecessary. The dealer is doing complimentary oil changes for the 1st year on my new Forester. So I naturally wondered what filter would be installed this past weekend when it was time for another change. They installed the same blue colored filter that the old Subaru branded filter looked like with the previous change. Except ... this new filter had no brand name or identity on it other than some small printing on the very end ... see pic. There is a prolific Subaru YouTube poster who goes by MrSubaru1387 who purchased and opened what looks like the very same Subaru replacement oil filter as what was installed on my car, complete with the painted arrow head next to Made in the USA. I could be wrong, but the unidentified new Subaru filter he dissected looks like a Champ-built Ecore design to me. Anyway, I share that long story because in the YouTube video this guy also pushed on the bypass filters with his fingers and remarked how much easier it was to more the bypass replacement valve than it was on the regular Subaru filter. Totally anecdotal, I know. But the implication is that Subaru is using a replacement filter with a much lower bypass setting. If true, I find that amazingly ironic. Tells me that if I follow the car manufacturer's OCI recommendations I can use any available oil filter spec'ed for this car regardless of bypass psi and sleep well at night. :)

Filter.JPG
 
Great explanation. Thank you. I'm a first time Subaru owner here and have found the focus on oil filter bypass psi by other Subaru owners unique, confusing, and I privately wondered if it was totally unnecessary. The dealer is doing complimentary oil changes for the 1st year on my new Forester. So I naturally wondered what filter would be installed this past weekend when it was time for another change. They installed the same blue colored filter that the old Subaru branded filter looked like with the previous change. Except ... this new filter had no brand name or identity on it other than some small printing on the very end ... see pic. There is a prolific Subaru YouTube poster who goes by MrSubaru1387 who purchased and opened what looks like the very same Subaru replacement oil filter as what was installed on my car, complete with the painted arrow head next to Made in the USA. I could be wrong, but the unidentified new Subaru filter he dissected looks like a Champ-built Ecore design to me. Anyway, I share that long story because in the YouTube video this guy also pushed on the bypass filters with his fingers and remarked how much easier it was to more the bypass replacement valve than it was on the regular Subaru filter. Totally anecdotal, I know. But the implication is that Subaru is using a replacement filter with a much lower bypass setting. If true, I find that amazingly ironic. Tells me that if I follow the car manufacturer's OCI recommendations I can use any available oil filter spec'ed for this car regardless of bypass psi and sleep well at night. :)

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Actually I watched his video and it an emergency replacement filter. Meaning that it would do in a pinch and not a permanent solution. Heck all we know is that filter could be running in bypass mode 24/7. I would just use a WIX filter. And your dealer is giving you two free oil changes is nice.
 
Great explanation. Thank you. I'm a first time Subaru owner here and have found the focus on oil filter bypass psi by other Subaru owners unique, confusing, and I privately wondered if it was totally unnecessary. The dealer is doing complimentary oil changes for the 1st year on my new Forester. So I naturally wondered what filter would be installed this past weekend when it was time for another change. They installed the same blue colored filter that the old Subaru branded filter looked like with the previous change. Except ... this new filter had no brand name or identity on it other than some small printing on the very end ... see pic. There is a prolific Subaru YouTube poster who goes by MrSubaru1387 who purchased and opened what looks like the very same Subaru replacement oil filter as what was installed on my car, complete with the painted arrow head next to Made in the USA. I could be wrong, but the unidentified new Subaru filter he dissected looks like a Champ-built Ecore design to me. Anyway, I share that long story because in the YouTube video this guy also pushed on the bypass filters with his fingers and remarked how much easier it was to more the bypass replacement valve than it was on the regular Subaru filter. Totally anecdotal, I know. But the implication is that Subaru is using a replacement filter with a much lower bypass setting. If true, I find that amazingly ironic. Tells me that if I follow the car manufacturer's OCI recommendations I can use any available oil filter spec'ed for this car regardless of bypass psi and sleep well at night. :)

View attachment 131788

Been well discussed here:

 
I’m sticking with an OE Subaru E-Core I picked up for an Ascent under powertrain warranty. That way, I have an invoice that can be used for a warranty claim.

Else, since this filter is an E-core, I could have used a MP7317/ST7317.
 
I must say you should consider Silicon ADBV, By pass higher pressure and 15 to 20 micron rates for the good efficiency. The media Pleat should not be an issue as long as you keep changing the Oil every six months.

ACDelco are made by Champion Lab as far as I know.

Hope this can help.
 
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