Oversize oil filter: Subaru Outback 2.5 4th gen
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DO NOT install an oversized oil filter on a Subaru without doing considerable research. Subaru oil filters spec a much higher bypass setting than most cars. A larger filter meant for another make that screws on will most likely have a much lower bypass setting.
The Purolator PureOne PL14612 oil filter is often suggested for Subarus. However, there's also the PureOne PL14610 which is the same filter but about a half an inch taller.
I'm not sure if that filter applies to your Subaru or not, but Purolator often has filters that are just a little longer than other filters it offers, so it's worth checking out their site and looking for them.
I'm not sure if that filter applies to your Subaru or not, but Purolator often has filters that are just a little longer than other filters it offers, so it's worth checking out their site and looking for them.
Originally Posted By: LT4 Vette
Any reason why Subaru has a high bpv PSI rating ?
search for the 1000 post thread here on the forums and you will come to the conclusion: nobody knows.
My in law used a napa silver on a 99 forester which is complete off spec for a smooth 20k~ OCI and the entire 1.5 quarts drained okay and 5 quarts back in and runs sooth as butter.
Any reason why Subaru has a high bpv PSI rating ?
search for the 1000 post thread here on the forums and you will come to the conclusion: nobody knows.
My in law used a napa silver on a 99 forester which is complete off spec for a smooth 20k~ OCI and the entire 1.5 quarts drained okay and 5 quarts back in and runs sooth as butter.
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Originally Posted By: skyactiv
DO NOT install an oversized oil filter on a Subaru without doing considerable research. Subaru oil filters spec a much higher bypass setting than most cars. A larger filter meant for another make that screws on will most likely have a much lower bypass setting.
I used to own a 2006 Outback and the OEM filter has a high 23 psi bypass valve setting. Most after market filters have a setting half that much. My understanding is that the boxer engines push some serious oil volume around so they need a higher setting.
My research found that Wix and PureONE filters had a >20 psi setting so that is what I used when I owned my Outback. Neither are what I would consider oversized.
DO NOT install an oversized oil filter on a Subaru without doing considerable research. Subaru oil filters spec a much higher bypass setting than most cars. A larger filter meant for another make that screws on will most likely have a much lower bypass setting.
I used to own a 2006 Outback and the OEM filter has a high 23 psi bypass valve setting. Most after market filters have a setting half that much. My understanding is that the boxer engines push some serious oil volume around so they need a higher setting.
My research found that Wix and PureONE filters had a >20 psi setting so that is what I used when I owned my Outback. Neither are what I would consider oversized.
Originally Posted By: BikeWhisperer
Originally Posted By: skyactiv
DO NOT install an oversized oil filter on a Subaru without doing considerable research. Subaru oil filters spec a much higher bypass setting than most cars. A larger filter meant for another make that screws on will most likely have a much lower bypass setting.
I used to own a 2006 Outback and the OEM filter has a high 23 psi bypass valve setting. Most after market filters have a setting half that much. My understanding is that the boxer engines push some serious oil volume around so they need a higher setting.
My research found that Wix and PureONE filters had a >20 psi setting so that is what I used when I owned my Outback. Neither are what I would consider oversized.
... and the insanely small size of the filter, and limited media area, requires a higher psi spec for bypass.
If the high bypass spec concerns you use the OEM blue can. It's a good filter.
Subaru's have gone millions of miles on after market filters.
Originally Posted By: skyactiv
DO NOT install an oversized oil filter on a Subaru without doing considerable research. Subaru oil filters spec a much higher bypass setting than most cars. A larger filter meant for another make that screws on will most likely have a much lower bypass setting.
I used to own a 2006 Outback and the OEM filter has a high 23 psi bypass valve setting. Most after market filters have a setting half that much. My understanding is that the boxer engines push some serious oil volume around so they need a higher setting.
My research found that Wix and PureONE filters had a >20 psi setting so that is what I used when I owned my Outback. Neither are what I would consider oversized.
... and the insanely small size of the filter, and limited media area, requires a higher psi spec for bypass.
If the high bypass spec concerns you use the OEM blue can. It's a good filter.
Subaru's have gone millions of miles on after market filters.
I'm a proponent of oversized filters but as was said earlier if you can't find one with the proper bypass specs than I wouldn't go bigger.
A recommended ultra or puro synthetic would be my choice if you can't find one of the two in an oversized version.
A recommended ultra or puro synthetic would be my choice if you can't find one of the two in an oversized version.
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Look in your engine bay, see how much bigger of a filter you have room for, measure length, measure/estimate width.
Find out the by-pass setting of your stock filter with a google search, or people are throwing around 20psi.
Check out the baldwinfilter websight. Baldwin Filters Home Click on, Products -size chart search- metric- enter M20x1.5
Then all their filters with M20x1.5 will come up, 5 pages of them. They list sizes smaller to largest. They list the bypass pressures for each filter, if they have an adpv, if they are revers flow, stand pipe, fuel, hyd, etc...
Find a filter with a bypass valve setting you want and cross over it's part number on other filter web-sights if you can't get a baldwin.
That's how I selected a 7" long filter to match the stock by-pass valve pressure with an adbv for my mini van. I wanted to get a local filter so I selected a wix thinking that it had ok quality.
Check different auto stores on line and crosse over the baldwin filter number on their web sight. A couple places will only cross over one or two filter numbers, so enter the filter number on other web sites to cross over to a better filter.
The bad thing about Amsoil is that they don't list filter specs for their car line on their web site. I hate that, like I want to trust what ever they pick out for my car but not prove that it's set up properly. My rant lol.
Find out the by-pass setting of your stock filter with a google search, or people are throwing around 20psi.
Check out the baldwinfilter websight. Baldwin Filters Home Click on, Products -size chart search- metric- enter M20x1.5
Then all their filters with M20x1.5 will come up, 5 pages of them. They list sizes smaller to largest. They list the bypass pressures for each filter, if they have an adpv, if they are revers flow, stand pipe, fuel, hyd, etc...
Find a filter with a bypass valve setting you want and cross over it's part number on other filter web-sights if you can't get a baldwin.
That's how I selected a 7" long filter to match the stock by-pass valve pressure with an adbv for my mini van. I wanted to get a local filter so I selected a wix thinking that it had ok quality.
Check different auto stores on line and crosse over the baldwin filter number on their web sight. A couple places will only cross over one or two filter numbers, so enter the filter number on other web sites to cross over to a better filter.
The bad thing about Amsoil is that they don't list filter specs for their car line on their web site. I hate that, like I want to trust what ever they pick out for my car but not prove that it's set up properly. My rant lol.
Originally Posted By: cptbarkey
Originally Posted By: LT4 Vette
Any reason why Subaru has a high bpv PSI rating ?
search for the 1000 post thread here on the forums and you will come to the conclusion: nobody knows.
I think the best theory is because of the very high volume output oil pumps in those engines.
Originally Posted By: LT4 Vette
Any reason why Subaru has a high bpv PSI rating ?
search for the 1000 post thread here on the forums and you will come to the conclusion: nobody knows.
I think the best theory is because of the very high volume output oil pumps in those engines.
Originally Posted By: ZeeOSix
Originally Posted By: cptbarkey
Originally Posted By: LT4 Vette
Any reason why Subaru has a high bpv PSI rating ?
search for the 1000 post thread here on the forums and you will come to the conclusion: nobody knows.
I think the best theory is because of the very high volume output oil pumps in those engines.
You would think if that was the case they would use a filter with much more media area. The spec'd filters, especially those from Wix, have so little media I won't use them.
Originally Posted By: cptbarkey
Originally Posted By: LT4 Vette
Any reason why Subaru has a high bpv PSI rating ?
search for the 1000 post thread here on the forums and you will come to the conclusion: nobody knows.
I think the best theory is because of the very high volume output oil pumps in those engines.
You would think if that was the case they would use a filter with much more media area. The spec'd filters, especially those from Wix, have so little media I won't use them.
Originally Posted By: webfors
Originally Posted By: ZeeOSix
Originally Posted By: cptbarkey
Originally Posted By: LT4 Vette
Any reason why Subaru has a high bpv PSI rating ?
search for the 1000 post thread here on the forums and you will come to the conclusion: nobody knows.
I think the best theory is because of the very high volume output oil pumps in those engines.
You would think if that was the case they would use a filter with much more media area. The spec'd filters, especially those from Wix, have so little media I won't use them.
Good question on the filter size ... does seem strange they use a super small filter. Maybe because of where the filter is located on some of those engines? - ie, nested up between the exhaust manifold.
Although, I have see Subarus with the filter base side down right on to of the engine, and the OEM filter is still super small.
Originally Posted By: ZeeOSix
Originally Posted By: cptbarkey
Originally Posted By: LT4 Vette
Any reason why Subaru has a high bpv PSI rating ?
search for the 1000 post thread here on the forums and you will come to the conclusion: nobody knows.
I think the best theory is because of the very high volume output oil pumps in those engines.
You would think if that was the case they would use a filter with much more media area. The spec'd filters, especially those from Wix, have so little media I won't use them.
Good question on the filter size ... does seem strange they use a super small filter. Maybe because of where the filter is located on some of those engines? - ie, nested up between the exhaust manifold.
Although, I have see Subarus with the filter base side down right on to of the engine, and the OEM filter is still super small.
Originally Posted By: LT4 Vette
Any reason why Subaru has a high bpv PSI rating ?
Again, no one really knows...
The one reason given that makes some sense is that the turbo engines were running into problems with clogged turbo banjo bolts, a wire screened bolt in the turbo oil supply line. These bolts would clog, restricting oil flow to the turbo, and causing failures. Having a higher by-pass reduces filter bypass events, minimizing the amount of possibly unfiltered oil or filter debris going thru the bolts, and reducing clogging. Maybe... and again, only the TURBO's ...
???
Any reason why Subaru has a high bpv PSI rating ?
Again, no one really knows...
The one reason given that makes some sense is that the turbo engines were running into problems with clogged turbo banjo bolts, a wire screened bolt in the turbo oil supply line. These bolts would clog, restricting oil flow to the turbo, and causing failures. Having a higher by-pass reduces filter bypass events, minimizing the amount of possibly unfiltered oil or filter debris going thru the bolts, and reducing clogging. Maybe... and again, only the TURBO's ...
???
If you have the room, take a look at the Baldwin B202. That is what I use on my S2000(for 90k miles) and it's a big filter with a 20# psid.
It will be 4 or 5 times as big as the stock filter for your car.
ROD
It will be 4 or 5 times as big as the stock filter for your car.
ROD
Originally Posted By: geeman789
Originally Posted By: LT4 Vette
Any reason why Subaru has a high bpv PSI rating ?
Again, no one really knows...
The one reason given that makes some sense is that the turbo engines were running into problems with clogged turbo banjo bolts, a wire screened bolt in the turbo oil supply line. These bolts would clog, restricting oil flow to the turbo, and causing failures. Having a higher by-pass reduces filter bypass events, minimizing the amount of possibly unfiltered oil or filter debris going thru the bolts, and reducing clogging. Maybe... and again, only the TURBO's ...
???
Good point. Why they put that screen there in the first place is nuts. I get it... don't want large chunks of debris entering the turbo housing.. but that's what a filter is for
Originally Posted By: LT4 Vette
Any reason why Subaru has a high bpv PSI rating ?
Again, no one really knows...
The one reason given that makes some sense is that the turbo engines were running into problems with clogged turbo banjo bolts, a wire screened bolt in the turbo oil supply line. These bolts would clog, restricting oil flow to the turbo, and causing failures. Having a higher by-pass reduces filter bypass events, minimizing the amount of possibly unfiltered oil or filter debris going thru the bolts, and reducing clogging. Maybe... and again, only the TURBO's ...
???
Good point. Why they put that screen there in the first place is nuts. I get it... don't want large chunks of debris entering the turbo housing.. but that's what a filter is for
Originally Posted By: webfors
Good point. Why they put that screen there in the first place is nuts. I get it... don't want large chunks of debris entering the turbo housing.. but that's what a filter is for
Kind of falls under the ANY OIL , perfectly clean or not, is better than no oil ... rule.
I considered the same thing with Subaru oil filters... is a lower by-pass possibly "better..." under some conditions... ? Again, that "some..." dirty oil vs no oil thing...
Probably seriously over-thinking this ... if it was critically important, why would any filter manufacturer risk using a lower psi valve if it might grenade an engine...?
Good point. Why they put that screen there in the first place is nuts. I get it... don't want large chunks of debris entering the turbo housing.. but that's what a filter is for
Kind of falls under the ANY OIL , perfectly clean or not, is better than no oil ... rule.
I considered the same thing with Subaru oil filters... is a lower by-pass possibly "better..." under some conditions... ? Again, that "some..." dirty oil vs no oil thing...
Probably seriously over-thinking this ... if it was critically important, why would any filter manufacturer risk using a lower psi valve if it might grenade an engine...?
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If this installation has the same exhaust arrangement as our '09 Forester, you won't be able to go up much in diameter.
It also might be a good idea not to increase length, since doing so will expose the filter directly to heat radiated from the exhaust.
This may explain the tiny filter used on these engines, although you see tiny oil filters on all sorts of applications these days. This may be because after breakin, there isn't much metal to filter out of the oil, so a larger filter with more media simply represents wasted capacity.
A Fram 3593A equivalent has the same base gasket diameter and the same threads and is used on earlier 2.2 Subarus as well as the flat six, but I'm not sure that it would be a wise choice in this application.
It also might be a good idea not to increase length, since doing so will expose the filter directly to heat radiated from the exhaust.
This may explain the tiny filter used on these engines, although you see tiny oil filters on all sorts of applications these days. This may be because after breakin, there isn't much metal to filter out of the oil, so a larger filter with more media simply represents wasted capacity.
A Fram 3593A equivalent has the same base gasket diameter and the same threads and is used on earlier 2.2 Subarus as well as the flat six, but I'm not sure that it would be a wise choice in this application.
Originally Posted By: fdcg27
It also might be a good idea not to increase length, since doing so will expose the filter directly to heat radiated from the exhaust.
I never gave this explanation much concern since, well, it's circulating hot oil. Any heat would be quickly regulated by the flow of oil.
That being said, the 7317 hangs an inch lower than OEM. The paint isn't baking off, the can isn't heat damaged, no sign of any impact from additional heat whatsoever.
It also might be a good idea not to increase length, since doing so will expose the filter directly to heat radiated from the exhaust.
I never gave this explanation much concern since, well, it's circulating hot oil. Any heat would be quickly regulated by the flow of oil.
That being said, the 7317 hangs an inch lower than OEM. The paint isn't baking off, the can isn't heat damaged, no sign of any impact from additional heat whatsoever.
Forget some of what I posted earlier, I learned recently about really long filters being sold generally with larger 32-40 micron ratings but the five inch sizes and under are mostly in the 22 micron range closer to what we want for cars.
I'm under the impression that manufacturers try to put the smallest filters possible on Cars to reduce material cost and the amount of oil they have to buy for production.
I'm under the impression that manufacturers try to put the smallest filters possible on Cars to reduce material cost and the amount of oil they have to buy for production.
Originally Posted By: webfors
Originally Posted By: fdcg27
It also might be a good idea not to increase length, since doing so will expose the filter directly to heat radiated from the exhaust.
I never gave this explanation much concern since, well, it's circulating hot oil. Any heat would be quickly regulated by the flow of oil.
That being said, the 7317 hangs an inch lower than OEM. The paint isn't baking off, the can isn't heat damaged, no sign of any impact from additional heat whatsoever.
The longer filter, at least on my Impreza, still has close to an inch between the filter and the exhaust... unless you sat stationary for an hour, I seriously doubt the filter is any hotter... and that filter location is already HOT, given the exhaust routing...
Originally Posted By: fdcg27
It also might be a good idea not to increase length, since doing so will expose the filter directly to heat radiated from the exhaust.
I never gave this explanation much concern since, well, it's circulating hot oil. Any heat would be quickly regulated by the flow of oil.
That being said, the 7317 hangs an inch lower than OEM. The paint isn't baking off, the can isn't heat damaged, no sign of any impact from additional heat whatsoever.
The longer filter, at least on my Impreza, still has close to an inch between the filter and the exhaust... unless you sat stationary for an hour, I seriously doubt the filter is any hotter... and that filter location is already HOT, given the exhaust routing...
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