Bypass PSI Question

Joined
Aug 13, 2022
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205
Okay,
So as I know now, Walmart is out of filters for the most part. I normally use basic filters like the Supertech or the Orange Can of Nuclear destruction.

I've started changing the oil in my my friends Subaru Forester with the 4cyl 2.5 non turbo engine. Calls for 0w20 oil which we are using now with some 5 k runs of Valvoline Restore and Protect. Maybe later we will try the ESP 0w30.

So I was looking at alternative filters since Walmart is no longer viable. When I first bought filters I looked in the filter book at Walmart and it gave the SuperTech6607 which is short, and the Fram PH7317 which is taller as the options. I bought both for the heck of it. Not thinking about bypass PSI as I figured the book was accurate (enough)LOL.

So now I'm looking at Purolator filters as an option (Good deals on Amazon at times)

On their filter lookup page I found this.

For the Forester it says the One PL14615 which is 2.93 inches tall and has a bypass psi of 20-30
When I cross referenced the SuperTech6607 which is 2.93 inches tall it gives the PL14612 with bypass of 14-18 psi.
When I cross referenced the Fram PH 7317 it gave the PL14610 3.52 inches with bypass of 14-18 psi.

So as a side note, I changed the oil in another friends Altima with the 4cyl. I looked up the filter and it said to use the SuperTech 6607 which I had on hand for the Forester. Cool!
So I asked Google AI what the bypass was for the SuperTech and it said between 8-11 psi. Remember, this is the same filter the catalog said to use on my friends Subaru.

Since the Subaru and Altima were calling for the same Walmart filter I looked at the Microgard Select because I know that is popular. The same filter came up as being the one to use for the Subaru and Altima. I could not find bypass pressure listed on website so I asked AI. It said:

MicroGard Select MSL57055
is often cross-referenced with the WIX 57055 or WIX XP 57055XP, which also utilize the 27 PSI bypass setting to meet original equipment (OE) requirements for high-pressure oil systems. Standard oil filters typically have much lower bypass settings, often between 8–15 PSI, which could lead to unfiltered oil circulating too frequently in engines designed for a 27 PSI threshold.

So this is putting the psi for the Microgard to be similar to the Purolator pl14615 for the Subaru, when for the Altima calls for a Purolator pl14610 with the 14-18 psi.

Basically I'm getting mixed psi settings for the bypass when I look at different filter recommendations from catalogs and websites.

We live in a warm climate with a cold winter morning being in 30's and a hot summer day over 100. 80's during the day for the most part.

Is the bypass psi really something I need to be concered about with my friends Subaru? It currently has the SuperTech 6607 in it.
Amazon has a great price on the 14612 right now. Under $3 for the "Tech" which list the same settings as the One 14612.

Share your thoughts please.






 
You have to either believe the filter look-up from the filter manufacturer or not. If not, then you have to prove to yourself that the one they specify is wrong. The bypass valve setting is not only dependent on the engine it's going on, but the filter itself in terms of the dP vs flow of the media and how that dP changes with expected loading during use. As you found out, you can look at 10 different oil filter brands/models specified for the same engine and there will be a difference seen in their bypass valve setting.

Not sure exactly which engine is in that Subaru, but maybe it has the lower flow oil pump. But If you want to feel comfortable about what filter to use, then choose the specified filter that has the highest bypass valve setting.
 
My thoughts on bypass valve pressure:
Assuming you have an engine in good shape, under good maintenance and you selected "the highest bypass valve setting" suggested above.

1) Were I to hear any rattling upon start up, an oil filter with a lower setting is the first thing I'd try.
Obviously, BITOGers' autonomic nervous systems factor in the ambient temp and selected oil grade.

2) I do not trust the consistency of the stamped leaf and coil springs used to actuate bypassing. Variations in the sheet and wire are beyond the control of those attending the 'high-tech production' of these parts. Ever see a video on bypass pressure?
 
1) Were I to hear any rattling upon start up, an oil filter with a lower setting is the first thing I'd try.
Obviously, BITOGers' autonomic nervous systems factor in the ambient temp and selected oil grade.
If an engine is making rattling noises on a start-up it's probably the ADBV leaking causing the galleries above the filter to drain out and not the bypass valve setting.

2) I do not trust the consistency of the stamped leaf and coil springs used to actuate bypassing. Variations in the sheet and wire are beyond the control of those attending the 'high-tech production' of these parts. Ever see a video on bypass pressure?
The bypass valve built into a leaf spring is still going to operate the same regardless if the leaf spring is ruffled and leaking some oil through the gap between it and the end cap.
 
Tokyo Roki oil filte, which OEM. I believe the PSI may be crucial....I have a Mazda 3 Turbo and buy my filters from Japan.
 
Okay,
So as I know now, Walmart is out of filters for the most part. I normally use basic filters like the Supertech or the Orange Can of Nuclear destruction.

I've started changing the oil in my my friends Subaru Forester with the 4cyl 2.5 non turbo engine. Calls for 0w20 oil which we are using now with some 5 k runs of Valvoline Restore and Protect. Maybe later we will try the ESP 0w30.

So I was looking at alternative filters since Walmart is no longer viable. When I first bought filters I looked in the filter book at Walmart and it gave the SuperTech6607 which is short, and the Fram PH7317 which is taller as the options. I bought both for the heck of it. Not thinking about bypass PSI as I figured the book was accurate (enough)LOL.

So now I'm looking at Purolator filters as an option (Good deals on Amazon at times)

On their filter lookup page I found this.

For the Forester it says the One PL14615 which is 2.93 inches tall and has a bypass psi of 20-30
When I cross referenced the SuperTech6607 which is 2.93 inches tall it gives the PL14612 with bypass of 14-18 psi.
When I cross referenced the Fram PH 7317 it gave the PL14610 3.52 inches with bypass of 14-18 psi.

So as a side note, I changed the oil in another friends Altima with the 4cyl. I looked up the filter and it said to use the SuperTech 6607 which I had on hand for the Forester. Cool!
So I asked Google AI what the bypass was for the SuperTech and it said between 8-11 psi. Remember, this is the same filter the catalog said to use on my friends Subaru.

Since the Subaru and Altima were calling for the same Walmart filter I looked at the Microgard Select because I know that is popular. The same filter came up as being the one to use for the Subaru and Altima. I could not find bypass pressure listed on website so I asked AI. It said:

MicroGard Select MSL57055
is often cross-referenced with the WIX 57055 or WIX XP 57055XP, which also utilize the 27 PSI bypass setting to meet original equipment (OE) requirements for high-pressure oil systems. Standard oil filters typically have much lower bypass settings, often between 8–15 PSI, which could lead to unfiltered oil circulating too frequently in engines designed for a 27 PSI threshold.

So this is putting the psi for the Microgard to be similar to the Purolator pl14615 for the Subaru, when for the Altima calls for a Purolator pl14610 with the 14-18 psi.

Basically I'm getting mixed psi settings for the bypass when I look at different filter recommendations from catalogs and websites.

We live in a warm climate with a cold winter morning being in 30's and a hot summer day over 100. 80's during the day for the most part.

Is the bypass psi really something I need to be concered about with my friends Subaru? It currently has the SuperTech 6607 in it.
Amazon has a great price on the 14612 right now. Under $3 for the "Tech" which list the same settings as the One 14612.

Share your thoughts please.
Don’t worry about it. Subarus have been using aftermarket filters all over, for a long time and they run just fine. My experience with Subarus and aftermarket filters for 20+ years has been great and I’ve never run an OEM filter.
 
Use whatever filter that filter maker catalogs for your application. If you hopscotch across the different filter makers assuming one filter SKU crosses to another without checking the application guide, you can find yourself out of application coverage sometimes for a particular SKU.
 
I run Subaruoutback.org and I use MSL57055 and countless people on that site use those as well. It's really nothing to overthink, just use it and move on in life.
Best quality out there at the moment it would seem. STP XL and Carquest premium are the same as well so anyone should be able to find at least one of those where they live.
 
No.

Bypass rating is based on the filter media of the filter, not the needs of the car.

The oil filter will essentially never open the bypass valve

Pick whatever oil filter you like and carry on
The original oil filter needs a high bypass setting, nothing to do with the oiling system? There usually is a reason why a car maker chooses an unusual spec., so it’s the particular oil filter they use? I definitely don’t understand that.

Different topic but neighbor has a 21 Forester and I wouldn’t be happy with the start up noise. Even warm it is pretty noticeable. I would try the Toyota S oil filter they sell for their Subaru clones to see if they have some magic to reduce the rattle. If it’s chain tensioners its probably no big deal. People like the vehicles and have them a long long time so it probably isn’t bearings, but I don’t know.

Looking at the Puro website the 2.4 brz which Toyota sells a clone of, uses the 2.4 engine 12-15 psi bypass, while the 2.5 engine in other models shows 20-30 psi. All the series from Boss to standard red use the same bypass settings.
 
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Yes, I am the founder of the website and the lead administrator since building it at the end of 2003 and opening it at the beginning of 2004.

Wow!! I’ve spent a lot of time on there; glad you have been able to keep it going, flourishing. I do miss LegacyGT.com though. A lot of priceless information has vanished at that site.
 
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