There isn't such a thing as "best" as long as it meets the specs listed in your owner's manual.
Discuss.
Discuss.
AWDFTW
I found this interesting (not a subaru, need to use translation from russian to english)
www.abw.by
When it comes to pressure differential across media there are five things that come into play.
Subaru oil pumps move about 5 quarts per minute at idle and 50 quarts per minute at redline. Depending on the viscosity of the oil (dramatically changes with temperature) at freezing temperatures there could be significant pressure differential even at idle and if you redline with cold oil it would have much higher pressure differential (if it weren't for the bypass valve) and even a high bypass pressure oil filter can be expected to bypass. But a bypass valve isn't on/off it opens just a little or a lot depending on how well the media flows (bypass valves sometimes have a pressure range described), and even when the bypass valve is open some of the oil is still going through the filter so it's not going to flush all the contaminants from the filter into your system - it's just that bypassed oil isn't filtered. Previously captured particles will remain in the filter's pleats.
So going into bypass isn't catastrophic or something to be avoided at all costs. You need bypass to prevent oil starvation. What you want to avoid is having the bypass valve open at normal operating temperatures at normal operating RPM ranges.
Проблема масляных фильтров
Чем лучше масляный фильтр будет очищать моторное масло от грязи, тем дольше прослужит двигатель, однако в конструкции фильтра предусмотрен перепускной клапан, после открытия которого в мотор поступает грязное масло, - экспериментально устанавливаем, когда же на самом деле этот клапан открывается
www.abw.by
When it comes to pressure differential across media there are five things that come into play.
- Bypass valve pressure setting (PSID - pressure differential)
- Restrictiveness (flow rate) of the media with a fluid at a certain test viscosity. A given filter's flow rate takes into account the surface area (pleats x depth).
- Oil pump flow rate (varies with RPM - higher RPM gives more flow in a positive displacement pump)
- Viscosity of the oil at standard temperatures
- Temperature of the oil (change in viscosity with temperature)
Subaru oil pumps move about 5 quarts per minute at idle and 50 quarts per minute at redline. Depending on the viscosity of the oil (dramatically changes with temperature) at freezing temperatures there could be significant pressure differential even at idle and if you redline with cold oil it would have much higher pressure differential (if it weren't for the bypass valve) and even a high bypass pressure oil filter can be expected to bypass. But a bypass valve isn't on/off it opens just a little or a lot depending on how well the media flows (bypass valves sometimes have a pressure range described), and even when the bypass valve is open some of the oil is still going through the filter so it's not going to flush all the contaminants from the filter into your system - it's just that bypassed oil isn't filtered. Previously captured particles will remain in the filter's pleats.
So going into bypass isn't catastrophic or something to be avoided at all costs. You need bypass to prevent oil starvation. What you want to avoid is having the bypass valve open at normal operating temperatures at normal operating RPM ranges.
It was probably a cheap cellulose oil filter and his engine may have been sludgy.
Now there's minor drama over Fram Ultra suddenly switching from two layers of all-synthetic media with wire mesh backing, to one layer of synthetic media, one layer of synthetic blend media, and no mesh backing, but it has more square inches of media (more pleats) and supposedly has even finer filtration but don't know about flow rate - the more pleats might make it equivalent. I'm still troubled by the low bypass pressure in those filters - although I do use that exact XG7317 in my Honda Fit.
The blue OEM filter is solidly good, so if in doubt, use that with confidence. It has never been known to fail or cause any problems in 6 month 6000 mile oil changes.
If you want "better than OEM" my top two choices would be the cellulose media based Tokyo Roki/Mazda N3R1-14-302 or the synthetic media based Purolator Boss PBL 14615, but if you stick to a standard maintenance schedule of 6 months or 6000 miles whichever comes first, then these premium filters are way overkill. Some people leave their oil filters in for more than one oil change but I would not do that. I change the oil filter with every oil change. I also wouldn't recommend extending oil changes beyond the 6/6k interval no matter what super ultra premium oil or oil filters you get.
Out of paranoia I would not use an oil filter that didn't have the high bypass pressure rating even though many people will say it's not important if the filtering media is high flow. In my mind, every parameter set by Subaru should be met or exceeded with no excuses. Again if in doubt, go with OE. No adequately fine filtering media has high enough flow for cold oil in freezing winter - I think all filters will bypass in those conditions, and a low differential pressure bypass filter will be in a wider open bypass longer.
If you want "better than OEM" my top two choices would be the cellulose media based Tokyo Roki/Mazda N3R1-14-302 or the synthetic media based Purolator Boss PBL 14615, but if you stick to a standard maintenance schedule of 6 months or 6000 miles whichever comes first, then these premium filters are way overkill. Some people leave their oil filters in for more than one oil change but I would not do that. I change the oil filter with every oil change. I also wouldn't recommend extending oil changes beyond the 6/6k interval no matter what super ultra premium oil or oil filters you get.
Out of paranoia I would not use an oil filter that didn't have the high bypass pressure rating even though many people will say it's not important if the filtering media is high flow. In my mind, every parameter set by Subaru should be met or exceeded with no excuses. Again if in doubt, go with OE. No adequately fine filtering media has high enough flow for cold oil in freezing winter - I think all filters will bypass in those conditions, and a low differential pressure bypass filter will be in a wider open bypass longer.
I forgot to add that you should shake every oil filter before installation and if it rattles at all, it's defective or damaged - don't use it. Better to leave your old oil filter on than use one that rattles.
I have heard nothing but good things about Baldwin filters but I just checked their application guide and their oil filter for Subaru only has a 14 psi bypass valve.
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I used to use the Wix 57055XP and it's still a fine filter and I would use it too. I found that when I switched to the Purolator my oil looked cleaner but it could have been illusory or just coincidence, but lately people have been finding the Wix XP filters have changed from wire backed synthetic media, to the same plastic mesh backed synthetic media as the Purolator. Both brands are owned by Mann-Hummel that also uses plastic mesh backed synthetic media in some of their filters.
Oils are getting better, but it's also in response to the higher demands of modern engines, especially direct injection turbos with low tension piston rings. Long oil change intervals wreak havoc.
There is something different about GDI soot so much so that it wears timing chains enough to cause premature elongation. I agree no filter is fine enough to capture it so that's why oil changes are so short now with GDI engines - to purge the unfiltered contaminants.
Online Oil Dilution Measurement at GDI Engines
In coming years a special focus in the field of GDI engines will be on downsized concepts and highly-charged gasoline direct injection engines. This is due to stricter emission laws, higher customer requirements, greater environmental awareness as well as high demands on materials and resources. Esp
I just chose the SAE because it's such a reputable bedrock organization but there are numerous other articles from various sources that have investigated this phenomenon and they all confirm the potential for fuel dilution of oil in GDI engines, especially at cold start, where gasoline may not fully vaporize, makes contact with the cylinder wall and washes into the oil. In addition during cold start engines may run rich to purposely quick-start the catalytic converter. It's worse in Turbo GDI because turbos need to run extra rich under boost, and a cold engine under boost is a fairly typical situation. Ideally you don't go into boost until the engine is completely warmed up but this is impractical with turbos that start to kick in as low as 2000 rpm under load. People need to start their engines and drive to their destination immediately, not drive around the block until oil temps reach 190.
It's the same thing with the soot issue - and thin oils may exacerbate it:
www.sae.org
It's the same thing with the soot issue - and thin oils may exacerbate it:
Correlating GDI and Diesel Soot with Carbon Black Surrogates: An MTM-SLIM Study
Legislations aimed at reducing CO2 emissions are driving significant changes in passenger car engine hardware and lubricants. Gasoline direct injection (GDI) engines generate combustion soot which can drive wear which is characteristically different to that observed in diesel engines. The increasing
A famous president once said "Trust but Verify". To be fair, I don't think a filter with a lower bypass pressure than Subaru specified is catastrophic, but it's not optimal. There are several oil filter choices that do meet that spec, so with that knowledge, my choice would be one that meets the spec rather than one that states it doesn't.
The goal of any filter manufacturer is to be efficient and if they can sell the same filter across 100 different vehicles instead of making a custom filter, it saves them money to do it that way. The filters that meet the bypass filter spec are intended only for motors that use that higher bypass spec - like some Mazdas and Subarus.
The goal of any filter manufacturer is to be efficient and if they can sell the same filter across 100 different vehicles instead of making a custom filter, it saves them money to do it that way. The filters that meet the bypass filter spec are intended only for motors that use that higher bypass spec - like some Mazdas and Subarus.
I also like the color purple, ever since childhood (love artificial grape flavor) but so few things come in purple. It's just not a popular color at all.
This might be off-topic but another Fram Ultra ADBV problem has emerged on BITOG - just adding it here because this is probably the biggest oil filter thread. Mods feel free to delete it if inappropriate. It just happens to be the same 7317 that our Subarus would use.
Frame Ultra anti-drainback valve out of place
7317 taken off a Ridgeline after 6,000 miles
bobistheoilguy.com
I'm not a fan of Whip City Wrencher but he did take this Microgard Select filter apart and it seems very well made:
On Bitog they're saying it's a Premium Guard Extended Life.
www.pgfilters.com
But no matter who makes them, they do look solidly built - is there any country of origin marking on it?
Trusted Oil Filter Manufacturer, Supplier & Distributor
Reliable oil filter manufacturer, supplier & distributor. High-quality filters for all applications. Contact us for your oil filter needs.
www.pgfilters.com
New Microgard oil filters at Oreillys
Has anyone else seen these new Microgard select oil filters? They have a silicone adbv and seal and at good for 10k and have an efficiency of 99% at 25 microns. Seem to be a dollar cheaper than the standard Wix. They look to be a Purolator One clone
bobistheoilguy.com
But no matter who makes them, they do look solidly built - is there any country of origin marking on it?
I think any filter that meets the bypass pressure thing is ok. Bypass only matters when the viscosity of the oil outstrips the bypass pressure differential, which can happen either from extreme cold (high viscosity) or high RPM with oil that hasn't fully warmed (high flow moderate viscosity). In a cellulose filter generally the flow rate at a given viscosity is less than a synthetic filter with depth filtration if both have the same surface area, so you'd see higher pressure differentials (more bypass events) typically with a cellulose filter.
The blue Subaru filters may need a higher bypass because they might be more restrictive than some other filters, but when oil is particularly thick or not very warm and pumping large volumes, even a high flow synthetic filter could end up in bypass. My car goes from engine start to merging onto a 50 mph highway within 30 seconds. The oil is not fully warmed up, and I need to run high RPM to merge. So for my engine I choose a synthetic high flow filter with a high (subaru spec) bypass pressure. I live in a warm climate so even stone cold my oil is between 70 and 80 degrees F but it's no where near operating temperatures, which are around 180-220 F
The blue Subaru filters may need a higher bypass because they might be more restrictive than some other filters, but when oil is particularly thick or not very warm and pumping large volumes, even a high flow synthetic filter could end up in bypass. My car goes from engine start to merging onto a 50 mph highway within 30 seconds. The oil is not fully warmed up, and I need to run high RPM to merge. So for my engine I choose a synthetic high flow filter with a high (subaru spec) bypass pressure. I live in a warm climate so even stone cold my oil is between 70 and 80 degrees F but it's no where near operating temperatures, which are around 180-220 F
I'm 200 yards from the highway. 30 seconds might have been an exaggeration I haven't used a stopwatch, but I don't sit and let the engine warm up.
In Hawaii, residential areas are literally attached to the highway (not a freeway) since we live on volcanic islands with houses built on the strips of land between the mountain and the sea. The posted speed limit is only 35 but the average speed is 50. Traffic is relatively heavy and fast because the highway essentially circles the island and to get anywhere you have to be on the highway except for where there is the freeway that starts 5 miles from my house.
The highway itself is lined with houses whose driveways are literally fed straight into the highway.
![Image]()
The highway itself is lined with houses whose driveways are literally fed straight into the highway.
I don't know but the Purolator Boss PBL14615 and Wix 57055XP have been out of stock on Amazon for a while.
I went and bought the new Hengst H345W from Rock Auto
www.hengst.com
I went and bought the new Hengst H345W from Rock Auto
Product
Another potential Subaru filter with the higher bypass pressure?
I noticed recently on RockAuto they have a new Hengst H345W for Subarus. I cannot find the bypass pressure spec anywhere but when you check other applications that use the same filter of another brand (like a PH7317) Hengst shows a different number for those applications. Additionally the only...
bobistheoilguy.com
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