I have two aims in creating this thread: First, to relay my experiences with oil filters. Second, to accumulate information about oil filers for the EJ25.

My '99 RS had a steady diet of Bosch oil filters from oil change one until today. I recently moved to an area remote from any Autozone and so had to buy a different brand of filter. I had heard many positive comments about Wix (NAPA Gold) filters and decided to try one of these.

The part number on the Bosch filters I've always used is 3310. These are about 3" in diameter and about 2.5" tall. The NAPA gold part number listed for the '99 EJ25 is 1365. Prior to 199, the part number is 1334.

The 1365 is noticibly smaller than the Bosch or the Subaru OEM Purolator. It is about 2.5" in diameter and 2.5" tall. However great the filter material in the Wix might be, there is only room for 70% as much of it relative to the Bosch 3310.

The 1334, on the other hand, is even larger than the Bosch. It appeared to be about 3.25" in diameter and 2.75" in height. The threads and rubber gasket were identical in dimensions to the 1365 and I have every confidence that the 1334 would screw on to the '98- EJ25 as though it were designed to do exactly that. I do not know if it has the required valve or not.

Anyway, this oil change has aroused my curiosity and I would appreciate your help. Please post if you have measurements and a part number on another brand of filter.


Thanks,

PK

Well I read all of your interesting thread but I can't really help much. I buy only genuine Subaru filters--which as has been noted before seem to be indentical in every way to the regular Purolator filter found at many autoparts store. (Except a missing "subaru" label.)

Three other filters to take a look at for performance are :

1) Mobil 1
2) K&N
3) Trasko

The K&N and Trasko ones IIRC are re-useable.

Read this or just go buy a Puralator PurOne.

http://members.nbci.com/minimopar/oilfilterstudy.html

Anyone know the part number for the EJ25 Mobil 1? It's never in the books.

Colin - could I ask you to measure your OEM filter?

skidplatez - do you have the dimensions on one of those Purolator Ones?

Hey Pk,

The OEM Puralator filter is 3" diamater and 3" tall. This shouldn't matter. It depends on what they use as the material inside. The oem filter for my dad's landcruiser is tiny relative to the aftermarket ones. As long as the filter fits over the seal tightly, it should be fine.

-JOE

EDIT: Hey Pk, puralator makes the OEM ones for subaru. I'm holding a Oem one and it says puralator all over it.

I, too, use the Bosch filters, so I'm no help either. I do 3000 mile oil changes, so I'm sure other filters would work just fine, but I like to throw money at my car so I spend the extra couple bucks. ;)

Anyway, I wanted to point out that there is not a Mobil1 filter for the 2.5RS. If you cross-reference all the part numbers, you might think that the MI104 (which is the SVX filter) will work. It appears to be the right size, and the threads are also the correct size. However, the endplate of the filter is concave (rather than flat like the correct filters are) so when you thread the MI104 onto an EJ25 you'll only get about 1 - 1.5 turns of thread engagement before the gasket contacts the block. I'm sure there are guys using these filters without problems, but there's not a chance in hell I'm going to trust that fitment. I wouldn't trust such a small amount of thread engagement for any critical part.

Pat Olsen
'97 Legacy 2.5GT sedan

I've cut up several EJ25 specified oil filters and the only ones I would use are:

- Subaru OEM (Purolator)

- Purolator L14460 and it's derivatives (Pure-One PL14460, and that other brand they sell at PepBoys) Note the Purolator's have a flat gasket compared to the OEM convex gasket. And for readers of the mini-mopar filter review, these Purolators have a metal clip holding the filter media ends instead of a string.

- Bosch 3310 (only thing being the bypass valve opens at
a somewhat lower pressure than the Purolator's. The filtering media while of a smaller area than OEM, seems to be of slightly better quality)

or if I had some more $$ a reusable CantonMecca filter.

Haven't looked at a K&N or Trasko.

I've cut open several new Wix based filters (Napa Gold, Castrol +) and found poorly glued media ends on most of them (one had already come apart at the seam -- meaning the oil would have gone thru unfiltered from day 1).

All other filters (Amsoil, Hastings, Fram, Mobil1, Pennzoil, etc. ) cross to a honda app and so the thread engagement is less than ideal like Pat mentioned and they all have anti-drainback valve's -- not the best thing for performance. ADV's are known to cause startup lifter noise on Subaru's...

PK, if you need some 3310's I have a few left over I can give you.

Where do you guys get Bosch filters? I don't think I've ever seen them anywhere.

Around here Bosch filters are sold at all Autozone locations. I don't know of any other retailer of Bosch products. For myself, I use purolator in my RS. Just recently I purchased a Bosch filter for my wifes P5.

I'd be happy to take those 3310s off your hands.

I know the Mobil 1 issue has been hashed over again and again. There is a Mobil 1 which is different than the SVX filter which some members are using. I just can't find the part number using a search, although I know I've seen it posted before.

Anyway, the Wix seems to have been a general disappointment. Just a word of caution to those who are using them or considering it.

Where can I find the PureOne? I don't recall seeing one of those locally.

P5???

P5????? I knew someone would probably ask:D
That would be a Porsche 5th generation 911T.


Ok, so I'm dreaming, but someday I will have one maybe not a 911 though. Really P5 is my acronym for Protege 5 which is the car my lovely wife drives and loves.

the NAPA #1334 is the correct one..also known as a Fram # ph3593a. all ej25's use this size....

The Bosches are the best filters. A friend of mine works at the AZ and can some times find a larger filter with the same valving and inlet size, but for the Subaru he had no luck. Generally speaking a larger filter is better(more cleaning area), all other things being equal. On my Corolla GTS I ran a filter about twice the size of the stock one.

Note: All of you prabably know but, always prime the filter before installing it.

p.k., what's the feasibility of just ordering the filters online from www.autozone.com? buy in bulk to save on shipping, and...no tax.

GTkrockett - AutoZone.com will charge you CA sales tax. Better to just stock up next time you visit the store. Edit: whoops, I was thinking of Arcata, not Arcadia. One is definitely closer to Oregon than the other!

sidewayz - The books definitely show the #1365 as the filter for '98- Subarus. The #1334 is listed for pre-'97s. Perhaps we should e-mail Napa. Is the #1334 really made by Fram though?

By the way, the part number for the Mobil 1 is #104. I will find one to measure next weekend.

I bought three new filters the day I got my RS (oem filters) time for the first oil change, and suprise they are Purolator. Probably an O.K. filter, but I wanted the jap. nippon filter. Anybody know how I can get them?

i would recommend AMSOIL. i think mine is sdf36 or 86, i can't remember. the guy who i bought my car from was big on it, so he made me too. what i've heard is that AMSOIL is the best. i'm not any oil filter expert, i'm just throwin in my dos centavos.

Hmm, well based on all the info here, there is nothing that suggests using anything other than the OEM filter provides any benefit. I stick to buying to using the OEM until somebody can provide some hard fact as to why a filter not specifically made for the 2.5 RS is better than one that is.

The main issues in my mind are quality of the filtering agent(s), proper valving, and the ability to withstand the high pressures that our engines produce. It doesn't seem anybody has enough data to even cover the valving issue with all the non-OEM filters.

- Steve

well if you want to get technical. The relleged "oem" units you are using are made by purolator, which in turn is marketed inder several other names.

Autozone(and other retailers) have a catalog which shows not only part number per car but thread pitch and size, valving and diameter of sealing ring. Using these values you can sometimes find a larger filter with the same characteristics (I couldnt for the subie.)

Bosch filters use a semi-synthetic filtering membrane which is rellegedly superior to all paper. Thats why I like em.

Using "oem" only, you may end up with the same filter sold at "jimbobs auto parts" down the street. Lets try to avoid getting "dealer only" uppity, a lot of times there is a superior non-stock part available. Example- stock Champion spark plugs.

It's not about the dealer at all. We all know, don't we, that Subaru in their owner's manual actually specs the NGK plugs, not Champions? I can't explain why they are shipped with crap plugs, and spec a plug which we all know is about as good as it gets. I switched to the NGKs, BTW. If you want to buy the Purolator filter (I have bought these at Advance Auto, BTW), which is the same as the OEM unit, more power to ya - same thing, you're just spending your money at a different place for the same product with the same specs, right?

I wanted to go with Amsoil - I run Series 2000 0w-30 in the engine (Redline in the tranny...) - but it appears the valve is less than ideal. Based on Amsoils product quality, I have no doubt that they are superior, even to Bosch, but I don't want to risk the fitment issue. As to the Bosch, BG5 (above) reports that the valve is not the same spec. I figure, why risk it? I'm running the best synthetic oil you can buy, changing it every 3k or less - you really think using a supposedly superior filter to the OEM one given what I'm doing really matters all that much? Probably not. Now, if there were an oil filter that obviously helped performance in some way, I'd be real interested. IMO I dont' need a filter that will last three oil changes... That said, if I knew, based on the fact presented, that there wasn't a fitment issue, and new the filtering material was superior, I'd be all over it.

Here's some technical info I'll add. Next time you change your oil filter, take note of how close the oil filter is to the headers on the 2.5. Certainly this is not ideal as one side of the filter will always be much hotter than the rest. Do you really want a larger diameter filter than sits even closer to the header? Something to think about. Perhaps this is why people aren't find filters over OEM spec'd size.

P.K. - I hope you get back to us and thanks for providing some numbers.

- Steve

I agree with everything you said except about the valving being different from stock on the Bosch. I dont know where BG5 got the info. My friend says this is incorrect.
Also in refernce to the larger filter my experience has been a longer filter, not wider. Altho these may exist. Thats one of the reasons I looked so hard is that there is plenty of room for a longer filter.
Anyway to each his own, I think in the grand scheme of things they are all pretty close. I liked the bosch for the filtering media which BG5 seems to have found superior as well.

so what's the bosche number for the 00-01 rs's ? is it the same as the 99 or is it different?
Thanks,
Robert

Subysouth?

I'm not sure what the concern is over the valving being "different". The anti-drainback valve is not a complicated item. It is just a one-way valve. Its sole purpose is to prevent the oil from draining back (in the reverse direction from the oil flow when the engine is running) from the galleries past the filter and back out into the oil pan. That's all. The design doesn't matter - there are only two stati for an anti-drainback valve: either it works, or it doesn't.

I cannot believe the '00s have a distinct part number from the '99s. Everything about the oil delivery system is the same, most notably the physical mounting to the block. A 3310 will work fine on the '00- RS.

As for bigger filters being closer to the header... A lot of Hondas and Nissans have the filter on the back of the engine, tucked up above exhaust parts and below the intake manifold, where there will be no airflow whatsoever. The filter on the EJ25 hangs down into moving air. Still, consider that you can hold your hand 3" away from the exhaust primaries when the engine is hot and feel warmth. On the other hand, if you touch the hot engine oil it will burn you. I REALLY doubt that a filter which closes the gap with the exhaust by .25" would be measurably hotter on one side than the other, because the radiant heat from the exhaust is a drop in the bucket compared to the heat of the oil. But even if it were, the overall temp would still be lower due to a larger surface area exposed to the air.

That said, I think a 3" filter is plenty large in diameter. I would indeed be interested if anyone knows of a quality filter with the correct threads and gasket diameter which is 3.5" long.

I just dont know your part numbers. Ive got a 2.2L Legacy and the Bosch oil filter for my car is 3310. If you have an EJ22 this is probably your filter as well(Impreza or Legacy.) The 2.5L motors I just dont know. Check AutoZone-they help me a great deal.

per this thread I just changed my oil with Mobil1 oil and a Mobil1 Filter and I could not be happier :)

also threw a fumoto valve on.

So did you observe the minimal thread engagement on that Mobil1 filter, as Pat spoke of?

Or did you not notice that part of the discussion, thus the reason you're happy? ;)

PK-

It's not the drainback valve people are talking about (which really wouldn't matter because of the filter orientation) It's the Bypass valve which is specific to each vehicle and application. this valve opens when the filter becomes clogged so as not to starve the engine of oil. Depending on the oil pressure in your car a lighter valve (than stock) could allow constant bypassing of the filter or a heavier valve could never open until the engine is already starved for oil.

BTW the Purone uses synthetic filtering media and a better ring seal and in all other respects is exactly to factory specifications.

I am a long time Amsoil filter user and now a dealer. The oil filter part # is SDF20 for ALL models and engines of Subaru from 1997 to 2000 (at least, since that is what my wife and I have). If you have different years, you can call or e-mail them (or me) for confirmation. The bi-pass valve needs to activate at the correct pressure to avoid engine damage. Amsoil's does. Amsoil filters exceed the capacity AND filtration cababilities of Mobil 1, WIX, FRAM, AC, Purolator, NAPA and the now discontinued HardDriver. The micron bi-pass filter (used in addition to a SDF filter) is in a class by itself.

PRODUCT DESCRIPTION
The AMSOIL Super Duty Oil Filter (SDF) is designed to provide maximum filtration while meeting the high flow demands of modern automobiles. The AMSOIL SDF contains a special cellulose, synthetic and glass blend media that offers the best possible balance of long life, high capacity and overall efficiency.

Traps Dirt Throughout Media Thickness
The AMSOIL SDF has a lofted fiber depth-type media that traps dirt throughout its entire thickness for exceptional filtering efficiency. It keeps oil clean and free of wear-causing contaminants. The AMSOIL SDF Oil Filter provides up to 100 percent more capacity and up to 20 percent greater efficiency than other filters provide. It is ideal for use with extended oil drain intervals.

Built for Rugged Performance
The AMSOIL SDF has a heavy-duty case of drawn steel. The case is double-crimped at the base with rolled-under seaming to withstand extreme pressure surges and road shocks.

Assures Oil Flow with Relief Valve
On most filters a relief valve is provided to assure ample oil flow. It prevents oil starvation in the engine in the event the media becomes saturated.

Prevents Oil Drainage During Engine Shutdown
On filter installations where the mounting is sideways or upright, dirty oil could drain out of the filter when the engine is shut off. The AMSOIL SDF has an anti-drainback valve that keeps trapped contaminants in the filter when the engine is not running.

APPLICATION
AMSOIL INC. recommends changing the AMSOIL SDF according to the following guidelines.

In gasoline-fueled engines using any AMSOIL motor oil except AMSOIL XL-7500 Synthetic Motor Oil, change the filter at 12,500-mile or six-month intervals. In gasoline-fueled engines using AMSOIL XL-7500 Synthetic Motor Oil, change the filter at 7,500-mile or six-month intervals. If a Hastings or other filter is used, filter should be changed at manufacturer recommendations.

When using an AMSOIL Oil Filter with conventional motor oils, refer to the owner's manual for the recommended oil filter change interval.

mrecknagel@wi.rr.com

I revived this thread because I thought I had discovered something new and exciting, when in fact it's already been discussed. Living in HI for the past 3 years I've been deprived of Autozone (where I used to buy Bosch filters), so I've been using the NAPA Gold (#1334). Last week I picked up a Bosch 3110 at Autozone here in CT. When I changed my oil and pulled off the NAPA 1334 I was surprised at the size difference. Looking a bit more closely, I noticed that the NAPA filter's end plate is slightly concave, so that the threads probably sit about 1/16"-1/8" or so below the filter O-ring. The Bosch 3110 (which is the same size/shape as OEM as far as I can see) has the threads nearly flush with the O-ring. I've been using the NAPA Gold filter for 3 years now, and although the threads aren't as high as the OEM filter, the thread engagement is more than sufficient.

I went back to Autozone and confirmed that the Mobil1 M304 has the threads even deeper - probably 1/4" or maybe even more - below the filter O-ring. I tried one of those out years ago (as I said 3 or 4 years ago in this thread! :eek: ) and only got 1 or 1-1/2 turns on the threads before the O-ring was against the engine block. Not good.

One additional bit of info. The same day I changed my oil I crawled under my Dad's '01 Outback wagon to find where it was leaking oil. His car has a filter on it that I've never seen before - longer and thinner than the little squatty ones I'm used to. It says "Fuji Heavy Industries" and "Genuine Part" on it (along with a bunch of Japanese writing) but I didn't see a Subaru emblem on it. It's possible that I just didn't wriggle around enough under there to find it the "Subaru" name on it. Or maybe it doesn't say Subaru on it. That made me wonder if it's some sort of generic FHI filter. I know Ford makes 2 different "grades" of parts - Motorcraft and FRPP (Ford Racing) - maybe Subaru and FHI do the same? Or maybe Subaru has shifted over to using filters made by its parent company rather than by Purolator? Does anybody know? Anyone have a newer Subie that can measure the OEM filter?

Pat Olsen
'97 Legacy 2.5GT sedan

I used a K&N oil filter, and its so much easier to replace when it comes time to change oil and filter. I hate using an oil filter cap wrench or w/e u call it with the K&N I just use a socket

Well, really, if you put the filter on correctly, you should be able to take it off by hand. But the little socket thing on the filter is a nice touch.

Pat

Well, really, if you put the filter on correctly, you should be able to take it off by hand.
Pat
Actually, the ONLY time I need a tool to remove an oil filter is when someone else replaced it last.
Either they overtorque it, or they didn't put oil on the seal prior to installing it.

WHY NOT USE A REMOTE FILTER AND USE AN HP1 BY FRAM OR EQUIVEANT. (SORRY FOR THE CAPS). The filter holds a qut by itself and has more suface area than two stockers.

Just changed the oil on my Dad's Outback, as it seemed to be leaking from the filter. Filter seemed to be on there tight, so I dunno why it was a problem - we'll see if a new filter fixes the problem. Anyway, I had mentioned above it was a different filter than I'd seen before. It turns out it does say Subaru on it, I just hadn't seen it the other night. The filter is very narrow - basically, the O-ring is just inside the outer diameter of the thing - probably about 1/2" more narrow than the Bosch 3110 (which I believe is the same size as OEM). It's about 1/4-1/2" taller than the 3110. The O-ring is pretty narrow, which probably shouldn't cause any problems, but I dunno. I don't like it! :)

WHY NOT USE A REMOTE FILTER AND USE AN HP1 BY FRAM OR EQUIVEANT. (SORRY FOR THE CAPS). The filter holds a qut by itself and has more suface area than two stockers.
I wouldn't add all that plumbing just for the sake of using a different filter. Maybe if I was going to be plumbing in an external oil cooler I'd think about it. I really don't think there's any need for a bigger filter - if Subaru's fine using a little filter on their 300hp, turbo'd 2.5L, then I'm sure my non-turbo making 100hp less is fine, too. However, if I can use a slightly larger filter in place of the little OEM one, then I figure it can't hurt to do so.

Oh, and one other bit of data... I didn't get any model year info, but apparently the NAPA Gold 1334 is used on lots of Japanese cars. The guy at NAPA specifically mentioned Accords. With that being the case, there may be other options (Mobil1, for instance) spec'd to fit Accords that would also work for us.

Pat

I just changed the original filter on my 06 and replaced it with a Napa gold, the Napa filter is slightly smaller diameter and has a flat gasket. I know this cause my filter end wrench would not fit the OEM.

Could you let me (us) know the part number of the NAPA Gold filter you used, K27? Just curious.

Pat

Patrick...was the filter black? There have been several revisions to the Subaru factory oil filters in the last few years. Most applied to the turbo models, but I believe they now have changed all of them to the newer style(slightly smaller) filter. There was also a bad batch that went out a few months ago. There's a thread, I think by Subie Gal, in the service or maintenance forum...somewhere. Might be stickied. Basically, they recalled certain filters for a manufacturing defect taht allowed oil to seep out. If his is one, he can take it to a dealership and have it replaced. She has the numbers of the affected filters on that thread.

Interesting, Charge, hadn't seen that. His filter was white (or maybe light grey - it was dark outside so I can't say for sure).

Found the thread in question - http://forums.nasioc.com/forums/showthread.php?t=864075&page=1&pp=30&highlight=oil . I still have his old, leaky filter out in the garage, I'll have to check what serial number and part number it is tomorrow. I'll be pretty pissed if it's in the known-to-be-bad batch, as my Dad just got his oil changed about 8 or 10 days ago. If this was a known problem 3 months ago, and it's in the F08/09 range, someone at the dealer's gonna be getting an earful from me. :devil:

Pat

It's a 1365

It's a 1365
Reading through the monstrous oil filter recall thread, it appears that all '06s use a different filter than the older cars, hence yours is a different number than what NAPA gives me (1334). I might have to swing by NAPA and take a look at a 1365 just for fun.

Pat

I've got an 05 STi that I am just about to do the first oil change on. Let me know if you want to know the dimensions of the filter.

-Wes