Skyactive high flow oilfilter
So, going back to this TSB back in the day when the turbo motor was new, the discussion I'm hearing is not about the ADBV but about the *filter bypass valve PSI*... Some of you guys may have heard about Subaru motors "requiring" a filter with a 27 psi bypass valve to make sure the oil keeps getting filtered under high pressure. Well, Mazda specs the turbo engine as requiring a 20.4 psi bypass rated filter. However, it has been shown that under the worst possible case scenario: An OCD grandma using a filter with a 8-11 psi bypass valve on a Subaru "requiring" a 27 psi rated filter, starting her car cold multiple times a day for only a mile of drive at time (to keep checking to see if her mail arrived). There was a photo of her engine at 90k miles and it looked brand new. Since she was OCD she did get her oil changed regularly, so there's that...
So, ultimately, even if the bypass valve is triggered and the oil is not filtering momentarily, well, once pressures come down then the filter starts catching stuff again, so it does get caught on the next pass, no biggie... so in the real world, it doesn't look like an issue to be concerned about. That said, I'm using the "oversize" Champion Labs made SuperTech MP7317 and Quaker State 5w-30 full synthetic every 5-5.5k on my Mazda 3 Turbo and she seems to be running well, with the oil not all that dark after that interval. I like with how the filter is 100% inverted that I can fill it to the very top with oil first, letting all the air bubbles out too, before screwing it in to help against dry start...
And yes, when I say "oversized" it is 20mm/0.75" longer than what is called for but still very clearly has plenty of clearance with the access panel cover. Going a bit longer also lowers pressure internally somewhat, so if the filter you are using has a <20.4 psi bypass valve it will help with the bypass being triggered less often. Honestly, I have no idea why Mazda calls for such a short filter when those 20mm longer still easily clears. Could it actually be better for oil pressure, with a fully inverted filter, for it to be smaller or with the pump pressure it shouldn't matter right?
One last thing on the bypass valve psi, it's not known for sure if every filter maker pretty much uses the same spring psi for all their sizes, or certain ones having stronger based on car maker requirements. But it also seems to be based on how sturdy the actual can construction is: filters with a thicker/stronger can, can handle higher pressures...
Anyway, my $.02 to think about...