Subaru and most other automakers just pick a vendor such as Purolator or Bosch or whoever and put the manufacturer's name on the filter. The manuf might give them specs to have the filter made. Subaru switched vendors in recent years I forget who is making the Subaru oil filters now. There was also an issue some time back with the gasket leaking on some of them I think.

Anyway I don't think you could go wrong with a quality aftermarket filter such as Wix (aka napa gold) or some others. Who has that link to where someone cut open various filters to see how well they were made. Some cheaper filters use cardboard and other junk in them that might not hold up well.

The requirement to use genuine Subaru filters by that rebuilder might be that the genuine filter is at least pretty good quality, whereas something from the dollar store might not be so good. Some people like to avoid what is sometimes called the orange can 'o death.

Could also be the genuine filter's bypass valve is like 24 psid I think, whereas many aftermarkets it is much lower say 9 psid.

 

That site I was thinking of had pics of a bunch of filters cut open. It was a few years old maybe there's an updated study now since manuf's may have changed some things over the years.

Here's a filter I cut open last year

 

Any filter built to the right specs and of quality construction will provide as long an engine life as the OEM filter- trick is to find such.

Take FRAM for example- cheap crap!


Dave

 

One site I found useful that was a bit more recent was:

http://home.mindspring.com/~ed_white/id7.html

The additional links on the bottom of the page are great in helping you decide which filters to use.

In Canada we don't have many retailers who sell Purolator filters, and I can get the Denso filters cheaper than the "six star" value branded filters from the dealer. The bonus is that the Denso filter also fits my wifes car so I only need to buy 1 filter and stock up on them.

 

I have always used Bosch filters. I know it's not necessary, but I still do 3000 mile oil changes on conventional oil, and the oil always comes out clean, so I've never switched filter brands.

 

That site I was thinking of had pics of a bunch of filters cut open. It was a few years old maybe there's an updated study now since manuf's may have changed some things over the years.

Is this the site?

http://www.knizefamily.net/minimopar/oilfilters/index.html

Here is the thread I found it from while reading about filters last year:

http://www.subaruoutback.org/forums/showthread.php?s=&threadid=12623

I read a bunch of oil threads and came to these conclusions:

Filters:
Fram which used to claim to be the best are now probably the worst. Some have actually had disintegration of internals found when changing filters.

Wal Mart SuperTech or Autozone filters are the least expensive but nearly the highest quailty.

Oil:
Any properly SAE rated oil is fine. For turbo models, there is a little more criticality in choosing oil.
Synthetics oil molecules are more uniform than conventional oil and are therefore a better choice for turbo applications.
Changing the oil and filter regularly at 5000 miles is more critical than the type of oil you use (short trip drivers should change at least this often, long trip drivers can safely go farther).

Personal Experience:
Changing the Oil regularly is the cheapest insurance for keeping your engine running. I have always changed my own oil 2-4 times a year and have never had an engine problem related to oil except once when the oil pump died on my 4Runner and the oil pressure idiot light was dead .

 

Any filter built to the right specs and of quality construction will provide as long an engine life as the OEM filter- trick is to find such.

Take FRAM for example- cheap crap!


Dave

Especially re-assuring as I think the new "Blue" filters from Subaru are manufactured for Subaru by Fram.

 

Especially re-assuring as I think the new "Blue" filters from Subaru are manufactured for Subaru by Fram.

Yeah, I'm waiting for them to show up at my dealer.

I will dissect my last black filter and upon removel my 1st blue filter, and compare, and maybe slap the whole mess on the parts counter if the new one is crap.


Dave

 

Original Poster here, thanks for everyones interesting replies.

As far as the new blue vs old black filters, i think that you can still buy the old ones by the case from:

http://www.subarupartsforyou.com/cp_partdetail.php?partid=2035

If they are a better quality than the new blue filters by fram, may be a good time to stock up.

 

And for the H6:

SPFY H6 oil filter


Dave

 

There are several threads on the SubaruForester.org forum about the SOA oem filters having changed from the Japanese-made to ones made by a North American manufacturer, presumed to be Honeywell, which also makes the Fram products.

Getting past the issue of Fram history and design, and the fact that the new oem filter internal construction appears visually the same as Frams, the discussion recently turned to the internal pressure relief valve. Apparently, research by some posters suggests that Subaru requires the relief valve to function in the range of 23 psi, whereas many aftermarket filters that will fit Subarus typically have valves that are designed to release at far lower pressures. The thought is that the aftermarket products are made to be applicable to a variety of cars, mainly based on their volume and attaching dimensions, whereas the filters made specifically for Subaru to its specs would have the required higher release pressure.

Whether the difference is critical does not appear to have been resolved, but obviously, the original posters' sources think it is important enough, for this reason or another, to specify using oem.

 

Thanks OM, you have vindicated my memory from 30 years back. As I said in the original post, I remember the primary reason for only OEM filters being something to do with oil pressure specs of some sort. Your info confirms that, thank you.

 

There's a huge thread on Subaru oil filter bypass pressure requirements on BITOG.
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1410171&gonew=1#UNREAD

Basically, the FSM calls for 23 psi for the bypass valve, and Subaru oil pumps flow unusually high volume. And it seems none of the aftermarket filters meet the bypass valve psi requirements. Lots of big ego debating on that thread, and stuff I don't understand, so I'm not sure what to make of it.

 

So the idea is that a Subaru oil pump generates an unusually high pressure at the filter, causing filters with low bypass pressures to mistakenly go into bypass, not filtering any oil?

That would be bad...if it's true.

Time to read the rest of the BITOG thread and try to cut through the BS.

EDIT: Wow, that thread is a little bit of useful information wrapped in 15 pages of p*$$**g match. Not a recommended read.

I have to admit, though, that my next oil filter will not be a Wix that fits every engine under the sun. It will be a Purolator, AC Delco, or Bosch that is Subaru-specific.

 

Walmart Supertech for me, they're around $2-3.00 for each of my vehicles and have great specs and reviews.

 

All i can tell you is that i have 206,000 miles on the orginal motor and I've been using wix(car quest) filters and changing my oil every 5,000. Since the motor is stilling going strong, I'm going to keep doing what i'm doing.

 

Blacky - Do you have a link for specs on SuperTech filters? I couldn't find anything online. Are they printed on the packaging?

Sario - I understand what you're saying. My engineering side just won't let me buy the filter with the low-pressure bypass now that I've read up on the differences. The argument for a filter with a higher bypass pressure makes sense to me.

 

....... My engineering side just won't let me buy the filter with the low-pressure bypass now that I've read up on the differences. The argument for a filter with a higher bypass pressure makes sense to me.

I can see why people would go only OEM, especially when it's only another coupe dollars to buy the subaru one. better than safe than sorry i guess. I would probably even jump on board with you, if i didn't really dislike my local dealership so much.

But I dont think with the amount off surface area in the filter the bypass is going to be pushed open untill higher RPMS. I toyed with idea of tapping the oil filter, and using a gage from work to test the pressure it. But i'm really not sure that would prove anything, I'm hardly and engineer. Plus i have to many half started projects around the house as it is

 

I can see why people would go only OEM, especially when it's only another coupe dollars to buy the subaru one. better than safe than sorry i guess. I would probably even jump on board with you, if i didn't really dislike my local dealership so much.

Order case lots from one of the dealers that sell parts online. Cheaper, they show up at your door, and you'll be set for a while.

 

Wow, I didn't know about the bypass pressure.

Subaru's bypass pressure is over 20psi, aftermarket filters don't have nearly that, that's good enough for me. Especially here where it may be -10F in winter.

So I assume the 'new blue factory fram' filters will have the correct bypass pressure...


Dave

 

Ok.. so I see all sorts of opinions on here about what kinda filters you should buy.. So what is the best? Should I buy a case of the old black filters, find a Soob specific aftermarket high quality filter, or stick with the new blue oem filters??

 

I'm hardly qualified to question the engineers at Subaru, so I'm just going to use the blue filters.

 

Ok.. so I see all sorts of opinions on here about what kinda filters you should buy.. So what is the best? Should I buy a case of the old black filters, find a Soob specific aftermarket high quality filter, or stick with the new blue oem filters??

If I knew of an aftermarket filter with as much media, good end-caps and spring, and the proper relief valve I wouldn't hesitate to use it.


Dave

 

CNY_Dave,

Let me see . . . Wix, Mobile 1, Amsoil . . . to name a few

Regards,
~Button

 

CNY_Dave,

Let me see . . . Wix, Mobile 1, Amsoil . . . to name a few

Regards,
~Button

The bypass valves on those open at way less than 23 psi. That's the whole point of that thread over on BITOG - they don't meet the specs listed in the Subaru factory service manuals.

Otherwise, they are quality filters, and many, many, people have run them for many, many miles without problems.

I'll stick with the OE filter until someone proves that the lower bypass pressure doesn't matter.