It seems there is not a consistent psi rating between different oil filters. Amsoil 11-17 psi, wix 23psi and not sure of napa platinum. I know wix is not a synthetic media, but that is what i am looking for.
Oem bypass rating '13 outback 2.5i
- Thread starter 11crv
- Start date
- Status
Use the Wix then, the Napa plat. is good too, just remember All those differences are not big, I wouldnt sweat it too much, I also wouldnt want the bypass rating too high either.
The bypass rating for a filter is set by the filter manufacturer not the engine manufacturer and it's based on many design factors of the filter, such as the media collapse (amount of DP the media can withstand), area of the filter media, type and efficiency of media, etc. Looking for a direct fit aftermarket filter that matches the OE filter bypass setting is not a useful endeavor. You will find many are close but you might find that some are way different and that will often be due to the fact that the design of the filter is way different than OE.
The OEM bypass pressure on the Subaru factory filters is very high. Not sure if there are any aftermarket filters with a higher rating.
The oil filter bypassing will not often cause the oil pump to bypass. The major restriction in the lube system is downstream from the filter. There are some very specific (uncommon) situations and combination of circumstances where it might be remotely possible (generally a restricted filter with a very high bypass setting combined with thick oil and high revs) but it's not worthy of a risk assessment study, nor any special preparation for on a street engine.
Originally Posted By: Jim Allen
The bypass rating for a filter is set by the filter manufacturer not the engine manufacturer
Sorry, Jim. That's not true for Subaru. They specify a filter bypass of 23-26 psi along with other critical parameters in the FSM.
Ed
The bypass rating for a filter is set by the filter manufacturer not the engine manufacturer
Sorry, Jim. That's not true for Subaru. They specify a filter bypass of 23-26 psi along with other critical parameters in the FSM.
Ed
Originally Posted By: edhackett
Originally Posted By: Jim Allen
The bypass rating for a filter is set by the filter manufacturer not the engine manufacturer
Sorry, Jim. That's not true for Subaru. They specify a filter bypass of 23-26 psi along with other critical parameters in the FSM.
Ed
Subaru is most likely talking specifically about their OEM oil filter is the spec is in the service manual. I agree with Jim that a filter's bypass setting is also based on the design of the oil filter.
If a stainless steel mesh filter was specified for a Subaru the filter's bypass setting certainly wouldn't be as high as a filter with cellulose media.
If say Purolator or FRAM or WIX designed an oil filter specifically for a certain Subaru engine, they would set the filter's bypass setting dependent not only on the oil volume and viscosity characteristics of that specific engine, but also the media flow characteristics (flow vs PSID & flow area) and media strength of the filter
Originally Posted By: Jim Allen
The bypass rating for a filter is set by the filter manufacturer not the engine manufacturer
Sorry, Jim. That's not true for Subaru. They specify a filter bypass of 23-26 psi along with other critical parameters in the FSM.
Ed
Subaru is most likely talking specifically about their OEM oil filter is the spec is in the service manual. I agree with Jim that a filter's bypass setting is also based on the design of the oil filter.
If a stainless steel mesh filter was specified for a Subaru the filter's bypass setting certainly wouldn't be as high as a filter with cellulose media.
If say Purolator or FRAM or WIX designed an oil filter specifically for a certain Subaru engine, they would set the filter's bypass setting dependent not only on the oil volume and viscosity characteristics of that specific engine, but also the media flow characteristics (flow vs PSID & flow area) and media strength of the filter
Originally Posted By: supercity
Is there a risk that a "correct" aftermarket filter with a higher by pass valve pressure will cause the oil pump to by pass more often or at higher RPM etc? Is this a cause for concern?
If an oil filter (like the OEM Subaru) has a very high bypass setting, then that means Subaru has (supposedly) designed the oil pump to put out enough oil pressure to achieve that much PSID inside the filter to cause the filter to bypass with no danger of cutting flow to the engine (ie, the engine supply pressure is still high when filter has 26 PSID across it). In other words, apparently the Subaru oil pump must put out more pressure than what normal cars put out, so in this case it wouldn't be a concern.
Is there a risk that a "correct" aftermarket filter with a higher by pass valve pressure will cause the oil pump to by pass more often or at higher RPM etc? Is this a cause for concern?
If an oil filter (like the OEM Subaru) has a very high bypass setting, then that means Subaru has (supposedly) designed the oil pump to put out enough oil pressure to achieve that much PSID inside the filter to cause the filter to bypass with no danger of cutting flow to the engine (ie, the engine supply pressure is still high when filter has 26 PSID across it). In other words, apparently the Subaru oil pump must put out more pressure than what normal cars put out, so in this case it wouldn't be a concern.
Originally Posted By: ZeeOSix
If say Purolator or FRAM or WIX designed an oil filter specifically for a certain Subaru engine, they would set the filter's bypass setting dependent not only on the oil volume and viscosity characteristics of that specific engine, but also the media flow characteristics (flow vs PSID & flow area) and media strength of the filter
The filters by the three manufacturers you list do have a filter specific for Subaru now. They all have a nominal 25 psi bypass. The factory filters regardless if manufactured by Honeywell, Tokyo Roki, or Purolator in both the larger and smaller sizes have a nominal bypass of 25 psi. Every aftermarket filter that "fits" a Subaru but is also specified for other makes does not have a nominal bypass of 25 psi.
Given those facts, I find it hard to argue that 25 psi is not a Subaru specification.
Ed
If say Purolator or FRAM or WIX designed an oil filter specifically for a certain Subaru engine, they would set the filter's bypass setting dependent not only on the oil volume and viscosity characteristics of that specific engine, but also the media flow characteristics (flow vs PSID & flow area) and media strength of the filter
The filters by the three manufacturers you list do have a filter specific for Subaru now. They all have a nominal 25 psi bypass. The factory filters regardless if manufactured by Honeywell, Tokyo Roki, or Purolator in both the larger and smaller sizes have a nominal bypass of 25 psi. Every aftermarket filter that "fits" a Subaru but is also specified for other makes does not have a nominal bypass of 25 psi.
Given those facts, I find it hard to argue that 25 psi is not a Subaru specification.
Ed
Originally Posted By: edhackett
Originally Posted By: ZeeOSix
If say Purolator or FRAM or WIX designed an oil filter specifically for a certain Subaru engine, they would set the filter's bypass setting dependent not only on the oil volume and viscosity characteristics of that specific engine, but also the media flow characteristics (flow vs PSID & flow area) and media strength of the filter
The filters by the three manufacturers you list do have a filter specific for Subaru now. They all have a nominal 25 psi bypass. The factory filters regardless if manufactured by Honeywell, Tokyo Roki, or Purolator in both the larger and smaller sizes have a nominal bypass of 25 psi. Every aftermarket filter that "fits" a Subaru but is also specified for other makes does not have a nominal bypass of 25 psi.
Given those facts, I find it hard to argue that 25 psi is not a Subaru specification.
Ed
Of course the "25 psi" is a Subaru specification ... I never said is wasn't. What I'm saying is that depending on the exact design of the oil filter brand (made for that Subaru engine), it may have a lower (or even a higher) bypass setting than a filter from Subaru. That's because the bypass setting is also dependent on the exact design of the oil filter ... not just the oil flow and viscosity parameters of the engine.
Originally Posted By: ZeeOSix
If say Purolator or FRAM or WIX designed an oil filter specifically for a certain Subaru engine, they would set the filter's bypass setting dependent not only on the oil volume and viscosity characteristics of that specific engine, but also the media flow characteristics (flow vs PSID & flow area) and media strength of the filter
The filters by the three manufacturers you list do have a filter specific for Subaru now. They all have a nominal 25 psi bypass. The factory filters regardless if manufactured by Honeywell, Tokyo Roki, or Purolator in both the larger and smaller sizes have a nominal bypass of 25 psi. Every aftermarket filter that "fits" a Subaru but is also specified for other makes does not have a nominal bypass of 25 psi.
Given those facts, I find it hard to argue that 25 psi is not a Subaru specification.
Ed
Of course the "25 psi" is a Subaru specification ... I never said is wasn't. What I'm saying is that depending on the exact design of the oil filter brand (made for that Subaru engine), it may have a lower (or even a higher) bypass setting than a filter from Subaru. That's because the bypass setting is also dependent on the exact design of the oil filter ... not just the oil flow and viscosity parameters of the engine.
Originally Posted By: edhackett
Every aftermarket filter that "fits" a Subaru but is also specified for other makes does not have a nominal bypass of 25 psi.
Yes, but are those other filters that "fit" actually specified by the manufacture to be used on that engine? That's the key.
Every aftermarket filter that "fits" a Subaru but is also specified for other makes does not have a nominal bypass of 25 psi.
Yes, but are those other filters that "fit" actually specified by the manufacture to be used on that engine? That's the key.
Baldwin filters make a oversize filter that has a 20 psi bypass that if you have the room would work.
Originally Posted By: edhackett
Originally Posted By: Jim Allen
The bypass rating for a filter is set by the filter manufacturer not the engine manufacturer
Sorry, Jim. That's not true for Subaru. They specify a filter bypass of 23-26 psi along with other critical parameters in the FSM.
Ed
They all "specify" something for the OEM filter but the aftermarkets don't necessarily follow that specification.
The '13 Forester 2.5 looked up in the Fram catalog is an Ultra XG7317 with a 13 psi bypass (and it's 13 psi all the way down the Fram application guide, syn and cellulose alike. The standard Wix # is the 57830, a cellulose media filter with a 28 psi bypass. Oddly that Subaru application is NLA with Puro, though they did list a part #. I couldn't find the Bosch spec but I guess I made the point.
Subaru can "specify" anything they like but the aftermarket knows they don't have to follow that spec... which could be for a myriad of excellent technical reasons. As I said, the filter bypass spec isn't really an engine parameter, perse, but is more of a filter parameter.
Originally Posted By: Jim Allen
The bypass rating for a filter is set by the filter manufacturer not the engine manufacturer
Sorry, Jim. That's not true for Subaru. They specify a filter bypass of 23-26 psi along with other critical parameters in the FSM.
Ed
They all "specify" something for the OEM filter but the aftermarkets don't necessarily follow that specification.
The '13 Forester 2.5 looked up in the Fram catalog is an Ultra XG7317 with a 13 psi bypass (and it's 13 psi all the way down the Fram application guide, syn and cellulose alike. The standard Wix # is the 57830, a cellulose media filter with a 28 psi bypass. Oddly that Subaru application is NLA with Puro, though they did list a part #. I couldn't find the Bosch spec but I guess I made the point.
Subaru can "specify" anything they like but the aftermarket knows they don't have to follow that spec... which could be for a myriad of excellent technical reasons. As I said, the filter bypass spec isn't really an engine parameter, perse, but is more of a filter parameter.
The Subaru specific Wix filter is the 57712 with a bypass of 23 psi. The Fram is the PH9715 with a bypass of 16-28 psi(Fram is real confident regarding their bypass operation, aren't they?)
I know Subaru has three sizes of filters now and has flip-flopped which to use on what engine the last few years. The point I wanted to make is that all sizes and manufacture of Subaru specific filters have the higher bypass. I'm sure the generic aftermarket filters listed work fine. Knowing the oil pressures and volumes Subaru engines run, there is a real reason for the higher bypass. I choose to stick with specification. Others are free to do as they see fit.
Ed
I know Subaru has three sizes of filters now and has flip-flopped which to use on what engine the last few years. The point I wanted to make is that all sizes and manufacture of Subaru specific filters have the higher bypass. I'm sure the generic aftermarket filters listed work fine. Knowing the oil pressures and volumes Subaru engines run, there is a real reason for the higher bypass. I choose to stick with specification. Others are free to do as they see fit.
Ed
Originally Posted By: edhackett
T The Fram is the PH9715 with a bypass of 16-28 psi(Fram is real confident regarding their bypass operation, aren't they?)
A range like that, 16-28, is the cracking to full open spec, i.e. the filter begins to open at 16 and is fully open at 28. It's the best way to spec the bypass pressure IMO because it give you the whole picture. Purolator specs are nearly all shown that way. If you see one number, that's usually the full open spec.
As to part numbers, I don't know why you got different part number than me. I just entered '13 Subie Forester 2.5L and got those numbers. Or is your the turbo? I glanced at those and saw some had different specs.
T The Fram is the PH9715 with a bypass of 16-28 psi(Fram is real confident regarding their bypass operation, aren't they?)
A range like that, 16-28, is the cracking to full open spec, i.e. the filter begins to open at 16 and is fully open at 28. It's the best way to spec the bypass pressure IMO because it give you the whole picture. Purolator specs are nearly all shown that way. If you see one number, that's usually the full open spec.
As to part numbers, I don't know why you got different part number than me. I just entered '13 Subie Forester 2.5L and got those numbers. Or is your the turbo? I glanced at those and saw some had different specs.
Last edited:
Mine is a turbo. The Wix finder gives the 57712 for the OP's Outback. That crosses to the Fram PH9715 on their site. It appears that Wix has made a full migration to the Subaru Spec Filter. Fram's finder often lists the older 7317 you got that pre-dated the Subaru specific 9715. The introduction of the FB series engines has complicated the filter choices.
There used to be two filters, one for the 6 and one for the 4. Now there are three for the 4 and the one for the 6. The three vary only in physical size, the 6 still uses the old larger "Honda" filter with the more normal 14 psi nominal bypass.
Ed
There used to be two filters, one for the 6 and one for the 4. Now there are three for the 4 and the one for the 6. The three vary only in physical size, the 6 still uses the old larger "Honda" filter with the more normal 14 psi nominal bypass.
Ed
On the Wix filter, I don't know the flow rate specs for the FB25 engine (2013 OB), but the EJ25 puts out 12.4 GPM at 5,000 RPM. Wix specifies the maximum flow capacity of the 57712 as 9-11 GPM. The WIX filters have substantially smaller filtration area than the OEM filters.
The new FA and FB series take a different filter than the older EJ series. The specs available from Subaru are the same as far as we can tell, but there must be some reason for two different part numbers. WIX specs the same 57712 filter for both the EJ series and the FA/FB series of engines.
Overall, I'd stick with the OEM filters, that's what I'm advising my mother to do with her new Legacy 2.5i.
The new FA and FB series take a different filter than the older EJ series. The specs available from Subaru are the same as far as we can tell, but there must be some reason for two different part numbers. WIX specs the same 57712 filter for both the EJ series and the FA/FB series of engines.
Overall, I'd stick with the OEM filters, that's what I'm advising my mother to do with her new Legacy 2.5i.
Originally Posted By: gpshumway
On the Wix filter, I don't know the flow rate specs for the FB25 engine (2013 OB), but the EJ25 puts out 12.4 GPM at 5,000 RPM. Wix specifies the maximum flow capacity of the 57712 as 9-11 GPM. The WIX filters have substantially smaller filtration area than the OEM filters.
The unknown about these oil pump flow specs ... is that with no restriction of the engine on the pump's outlet, or is that the actual flow going through the engine's oiling system? If it's just the output of the oil pump without the restriction of the oiling system, then the actual flow through the engine could be less.
I highly doubt anyone has independently measured the flow rate, so the factory spec is open to interpretation IMO.
On the Wix filter, I don't know the flow rate specs for the FB25 engine (2013 OB), but the EJ25 puts out 12.4 GPM at 5,000 RPM. Wix specifies the maximum flow capacity of the 57712 as 9-11 GPM. The WIX filters have substantially smaller filtration area than the OEM filters.
The unknown about these oil pump flow specs ... is that with no restriction of the engine on the pump's outlet, or is that the actual flow going through the engine's oiling system? If it's just the output of the oil pump without the restriction of the oiling system, then the actual flow through the engine could be less.
I highly doubt anyone has independently measured the flow rate, so the factory spec is open to interpretation IMO.
Yes! Actual flow thru the engine WILL be much less. Look at the lube circuit of the average engine, see the 1/16" (or less) diameter passages and galleries and .002" bearing clearance and tell me it's going to flow 12 gpm. It won't. Every oil pump spec I've seen is the unrestricted maximum flow of the pump, not the flow thru the lube circuit. Maybe it different for Subies but I don't see how.
A turbo engine requires more oil flow because the turbo takes a big chunk of almost unrestricted flow. The pressure drop at the end of a turbo oil line is huge.
A turbo engine requires more oil flow because the turbo takes a big chunk of almost unrestricted flow. The pressure drop at the end of a turbo oil line is huge.
- Status
