Subaru 15208AA160 and Mazda N3R1-14-302 cut open and compared

Subaru uses a 23psi bypass. I spend $4ea for Subaru blue cans and don't see what the problem is, Subaru is willing to warranty the engine with them and fiber end caps are no big deal. I do like the Wix/Napa Gold filters also 23psi bypass and a much nicer ADBV it is not just silicone but it is larger and flatter with reinforcements on the back side, it seems to be a good solid filter for $6.
 
While to two black can filters do appear very similar, unless one knows the efficiency specs of both can't say that they are identical OFs. That even if the bypass spec on both is the same. Being OEM, highly unlikely efficiency spec of either or both can be found.

As for the Suby OEM made by Fram, I'm sure it works as intended and warranted by Subaru and can be used with confidence.

That said, it is perfectly fine to have a preference for a construction type in a spin on filter. I do, and I seek out filters with that type of construction. Fwiw, I rarely if ever run OEM filters in the vehicles I maintain.
 
Thinking over the comments about needing to know the filtration efficiency and delta-p to be sure they're equivalent.

I guess I would have to amend my conclusion to say that they're equivalent as far as it's possible to determine without proprietary data. But this conclusion is still at least as useful as any conclusion one can reach about choosing an aftermarket filter, or even choosing the blue Subaru filter over the black one. In the absence of the proprietary information, we have no filtration efficiency data on which to make a comparison, so if we reasonably assume the stock filter is a good choice, our options become a) Buy the stock black filter on the gray market and trust that it's best; b) Buy the Mazda filter and trust that it's the same efficiency because it appears to be; c) Buy the blue filters and trust they are the same or better efficiency; or d) Buy aftermarket filters and hope that you are not unknowingly compromising efficiency compared to any of the previous choices.

All those choices contain guesses. Subaru uses two different filters. They both at least meet Subaru's specs, but one or the other could exceed the specs and filter better. There are eleventy gazillion aftermarket choices, including the Mazda, but we can't know which of them, if any, have better or worse filtration than stock.

So either we do not have enough data to make any choice, or we proceed without that particular data point and make choices based on what we can know. And that leads us away from using any of the three filters I took apart, and toward using aftermarket filters for which efficiency data is published. We still can't know if it's better than stock, but at least we can know what it is for that particular product, and we can choose based on what is generally known about how good a filter can objectively (as opposed to comparatively) be.
 
If filter efficiency is the main important factor, then choose a filter that has published ISO 4548-12 information from the manufacturer that meets your goal.

If construction is the main important factor and efficiency isn't that important, then choose a filter that shows the construction you want/need. Construction also includes reliability during use, meaning it doesn't fail in some way.

If you want both, then you have to blend the efficiency and construction factors to an acceptable combination that you're comfortable with.

From an engineering viewpoint, as long as the construction and build quality doesn't lead to failures, then its construction is acceptable for the job. An oil filter is a throw away item after it does its job.

Purolator PureOne filters were super popular here before the media tearing reports started pouring in. It was advertised as ISO 4548-12 efficiency of 99.9% @ 20μ, had decent construction with metal end caps, and had good flow vs delta-p (which was proved by data from Purolator). And the cost was reasonable. But when the media tearing started, people dropped the PureOne and switched to the Fram Ultra (including me), because it met the desired efficiency, construction and reliability requirements for many. And its cost was also reasonable. Cost is yet another factor for many, but can be justified to some degree by what you get.
 
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It's a long shot, but I wrote to Tokyo Roki and asked them if they will provide specs for those two filters.
 
It's a long shot, but I wrote to Tokyo Roki and asked them if they will provide specs for those two filters.
Probably is a long shot, but if they respond with actual efficiency and flow data please post it up.
 
Probably is a long shot, but if they respond with actual efficiency and flow data please post it up.
Well, I did receive an automated reply from their contact form, which is promising:

1649622926294.png


In case anyone here can't read Japanese:

1649623022008.jpg
 
^^^ At least the robots care. 😄

BTW, if they come back with a response that the information is "propitiatory" then that means it's not very good. No company in their right mind will hide performance data that bolsters their products.
 
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^^^ At least the robots care. 😄

BTW, if they come back with a response that the information is "propitiatory" then that means it's not very good. No company in their right mind will hide performance data that bolsters their products.
Not sure if "propitiatory" is a joke about translation error, or just a slip on your part, and don't want to assume.

But it's possible their contracts with Subaru and Mazda do not allow them to discuss it. Which would make sense, in a way; if Subaru won't tell us, they're not going to leave a loophole open for us to get the data from the supplier.

That's the response I expect, anyway. We'll see.
 
Not sure if "propitiatory" is a joke about translation error, or just a slip on your part, and don't want to assume.
It's not a joke about translation of the robot response or a slip on my part. What I'm saying is that if a company will not tell you what the efficiency specs are, when nearly all other filter companies tell you, then there's a reason for them not divulging the information.

For instance, WIX use to show the efficiency of their full synthetic (top of their line) XP oil filter as 50% @ 20u. Then all of a sudden that efficiency spec disappeared from their website and showed nothing. Then if someone called WIX and asked what the efficiency of their XP filter was, they would just tell you that "it's proprietary". Why do you think they would say that? :unsure: 😄

But it's possible their contracts with Subaru and Mazda do not allow them to discuss it. Which would make sense, in a way; if Subaru won't tell us, they're not going to leave a loophole open for us to get the data from the supplier.

That's the response I expect, anyway. We'll see.
Yes, in this case that could be true, and you would have to contact Subaru and Mazda instead. They may also tell you the information is "proprietary". If they say they don't want to share the information, then it's "proprietary" by the very meaning of the word. Like said, why would any company hide stellar performance specs on anything they sell? Next thing you know, car makers that make weak powered cars will say the torque and HP numbers are "proprietary" because they don't want the public knowing how lame they are, lol.
 
It's not a joke about translation of the robot response or a slip on my part ... if someone called WIX and asked what the efficiency of their XP filter was, they would just tell you that "it's proprietary". Why do you think they would say that? :unsure: 😄
If they said it was proprietary, then I'd think they were hiding something. But if they said it was propitiatory, which was the word you used that I was commenting on, I would ask them whether it was a joke or a mistake. :)
 
If they said it was proprietary, then I'd think they were hiding something. But if they said it was propitiatory, which was the word you used that I was commenting on, I would ask them whether it was a joke or a mistake. :)
LoL ... autocorrect victim. I guess depeding on the cirucmstances it could also be propitiatory (intended to reconcile or appease). Obviously I meant proprietary since it came out right in post #30.

1649633971828.jpg
 
LoL ... autocorrect victim. I guess depeding on the cirucmstances it could also be propitiatory (intended to reconcile or appease). Obviously I meant proprietary since it came out right in post #30.

View attachment 95914
Yes, by that point it was obvious you'd always meant proprietary and just had some sort of slip-up that you hadn't noticed. But initially, because you put it in quotes, I didn't know whether it was a slip or a joke about what kind of fractured English reply I might receive.
 
Their robot response wasn't too bad, but it will be interesting what the actual human response might be.
 
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I'll be much more than surprised if TR releases the efficiency data on either or both of the black can OEM OFs. And, in ISO 4548-12 form which is standard of efficiency ratings.

I guess 'shocked' would be an appropriate word for me IF it happened.

Using what data is available on Asian OEM OFs efficiency, which is very limited, I wouldn't expect either of them to be very efficient. And that's being kind.
 
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Ill
Most of you will probably already be aware that the Tokyo Roki 15208AA160 "black" filter that comes on Japan-built Subarus is not available in the USA. US Subaru dealers replace it with 15208AA15A "blue", made by Fram, at the first oil change. It's widely understood that the Roki filter is superior. Subaru fans have been buying Mazda N3R1-14-302 Tokyo Roki filters, intended for the RX-8, in the belief that they are the same filter as the Subaru 15208AA160. But are they? I decided to find out.

Here we have a disassembled Subaru black next to a disassembled Mazda filter.

View attachment 95724

I don't have a fancy-pants filter cutter like the rest of you experienced fanatics; I'm an inexperienced fanatic, so I opened these with an angle grinder.

They certainly look identical at first glance. The external dimensions are the same; the baseplate is the same. Internal construction is the same, with the same anti-drainback valve, and the same steel spring plate holding the filter cartridge down. The filter cartridge is the same length and diameter, and contains the same number of pleats (55), joined with a metal clip.

The bypass valve is spot-welded into the filter end cap:

View attachment 95725

So far so good. But we know that Subaru guys are laser-focused on the bypass valve pressure. How to compare that? Hmm.

I put each filter cartridge in a cup on a scale and zeroed it:

View attachment 95726

I put a piece of blue tape on a driver:

View attachment 95727

Then I pressed down the bypass valve with the driver until the tape touched the end cap, and noted how much force the scale showed. I don't have pictures of this, because I only have two hands. You'll have to take my word for it. The Subaru filter took 5lb 6.2oz of pressure to open the valve to the tape, and the Mazda filter took 5lb 5.7oz of pressure. I would consider those results within the range of measurement error or manufacturing tolerance. Looks to me like it is the same valve. (Please note that I am not saying these are ~5-6psi valves. These numbers don't mean anything except for comparison to each other.)

So are they the same? Well, there is one difference. The center core is different. Here's the Subaru:

View attachment 95728

And the Mazda:

View attachment 95729

I didn't disassemble them to count the holes, but my eyeball estimate says the Subaru filter has about 50% more holes than the Mazda. What I don't know is whether that makes any difference. I took a look at a few other filters I have on hand (Champ, Wix, Baldwin, Purolator Tech, and Subaru blue) and the perforations in the core vary, but none of them have as many holes as the black Subaru pictured here. So I'm going to guess it doesn't matter, but I'm sure one of you guys will set me straight if I'm wrong.

So, assuming the core perforations are a difference that makes no difference, then my conclusion is that the Mazda N3R1-14-302 is functionally the same as the Subaru 15208AA160, is built to the same quality, and is a good choice to replace the USA-unavailable Subaru filter if you want the closest thing to what the engine was built with.

Just for a fun comparison, here's a Subaru 15208AA15A "blue" filter cut open:

View attachment 95735

That's a Fram or I'll eat dirt. The less said about it the better.

Comments are welcome.
never use the blues again. Just because they did the same on a dry filter and the paper end caps came off on the ADBV like glue. So assuming oil moisturizes the caps still. I only use the NR14’s and very happy. With PP or PUP which ever I’m feeling. I’ve got 2 and a blue. An just used one of the NR14’s. I’ll order another when down to 1. Those that don’t care that’s all on you.
 
They all look very good. The blue Subie filter looks better that a standard orange Fram. Looks closer to a tough guard to me minus the silicon ADBV..
I don’t trust that fiber end cap and in this day and age it’s uncalled for. Even a carbon composite like a Walmart Supertech filter works better.
Just no need. Maybe 20 years ago but this is 2020’s.
 
I don't know that there's hard data on that. Only Subaru would know the failure rate of the blue Subaru filters, and they don't publish that data. Everything else is anecdotal.

You don't have to look too hard to find people on this site who have had failures with Fram filters of this design, and it's reasonable to suspect that such failures do happen with the blue Subaru filters; it's not a question of "if" but "how often." Probably the answer is "not often enough to justify the cost of improvement."

You strike me as someone who knows there's no such thing as a solution, only a tradeoff. I don't doubt they're made to Subaru's specifications, but those specifications were almost certainly written with a cost/benefit analysis that said, "If we save a total of X on this component by accepting a failure rate of Y, then as long as the cost of replacing Y engines under warranty is less than the savings X, we're ahead." So overspec'ing the filter is not in their best interest even if it does cost them the occasional warranty claim, and there's the tradeoff.

Can I prove that? Not without access to Subaru's confidential data; but it seems at least plausible given what we see during the teardown.

The car owner's incentives are different. You probably also know what marginal utility is. He only has to worry about his own car, and the small amount of additional fail-safe provided by a higher quality filter may be worth it to him.

All that said, I'm going to stop using these Mazdas. They're too expensive. :) I'm not going to switch to the blue Subaru filters, but I'm sure Wix, Champ, or Purolator are fine.
Not expensive compared to 2700 dollar replacement jdm motor that’s for sure. Yes Puralator is probably the next best but at a draw back of bypass pressure. Granted this is a Delta pressure. Winter would be the concern vs cold start up. MrSubaru did a filter review. And if a Subaru master tech says he’s not using the blues. That’s all I need.
 
It's the same thing with Honda and Tokyo Roki and afterwards using the fram filters.
They also prefer the Tokyo Roki ,and now they are using anything that's available (purflux,Mahle tennex,...)
They look identical actually.
Whats the bypass pressure rating for the Subaru ?I just recently noticed the RX8 filter cross referenced with the s2000 filter and that was rated at 1bar (16psi).
It’s not it’s 18-24 psi. Your talking about the Gen 1 RX8 filter not the NR14
 
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