nominal micron rating.

[schwartr88]

If I understand correctly the nominal micron rating is 50% efficiency. So if a filter like wix or supertech have a nominal rating of 19 or 20um, wouldn't that make it a pretty lousy filter? A regular purolator is 97.2% effective at 20 um (47% more effective than the leading national brand j/k). But yet these filters get great reviews and show good particle counts.

What am I missing?

 

[Gary Allan]

When you're looking at the Wix spec's ..the "nominal" rating (typically 19um for an automotive filter) is the single pass rating.

The multipass test is the one with the beta 2/20 = x/X. This is typically finer.

You usually don't see fixed particle sizes and a floating beta ratio number ..but that's what you've got there. Beta20=35

That's a rather fine filter for what I'd expect from a Premium Plus (regular

)

ST is probably a beta30 or 40 = 20.

 

[schwartr88]

ST is probably a beta30 or 40 = 20.


Those are marble sized particles there. But they got good reviews and particle counts, so they cant be all that bad. Thanks

And yes, according to Purolator its Purolator premium plus (not the pureone) is 97.2% effective at 20um. But no other info was given by them regarding if it was single/multi pass or what ever.

 

[Gary Allan]

Yes, those seem like boulder size particles ..but not all that frequent when you realize how the beta system works. Many WIX filters are in the 40um range at the 95% level. Many are lower.

Even Beta5=20 means 95% of particles 5um and larger. The 5% that does get through WON'T JUST BE 5um particles and LOWER. The % of larger particles will surely be low ..but it's not like a fixed doorway. It's a minor distinction ..but it has its presence in terms of misconcepts.

 

[schwartr88]

So in laymans terms: just use the ST or any other filter without worry?

 

[Gary Allan]

Essentially ..yes...and if you don't mind paying more for standard features ..even a Fram. Now if you want finer filtration ..or are considering doing max recommended OCI's or doing every other filter changes ...or you just want the best (or "better") ..then graduate to a WIX, PureOne, M1, K&N, or EaO. WIX I don't necessarily put into upgraded filtration ..but the robust construction surely puts it in that class of filter. I also imagine (that is, my unsubstantiated speculation) that their process variable and pass:fail criteria in raw products is probably up there when compared to the lower offerings (some of them they may in fact produce to vendor spec's for more competitive pricing).

 

[schwartr88]

For 3-4k oil changes I have heard that there is no reason to use filters like P1 or M1 ect. I have also heard that using such a filter (for my oci) will not gain me any engine life. I was just confused because filter like Fram TG claim to filter out 99% of >20um and the ST is around 50% at 20 um (i think??) I am just looking for a good cheap filter that will do its job and help me reach 250k miles.
Better filtration sounds good, but people have gone 250k+ miles on ST (so Ive heard) so it looks like they will work just as well...

 

[Gary Allan]

Don't use a filter that you can get no value out of. Let me see if I can communicate my thoughts on this.

If your 3-4k mean 3-4 OCI's per year ...then you can surely use the upper tier filters if you're willing to leave them on for every other OCI. OTOH, if your 3-4k means 2 OCI's a year ..then you're going to be either changing a lower end filter every OCI, or an upper end filter every other OCI. This too "depends". Any filter (probably) has a solid 10-15k of usable life if there's not a majority of use in the enriched combustion cycle.

Now as far as realizing "gain" in longevity ..there's probably none to be had. Keep in mind that there are broadly varied states that one can make it to 250k without rendering the engine unserviceable ..just like you can be in various states of health at age 75 or 80 that are dependent upon how you were cared for on the way there.

So, what's you annual mileage? If it's 12k or more, you can easily use the upper tier filters every other OCI and feel confident that they're doing a good job. That will allow you the finer filtration without added cost.

 

[glenncof]

Yea, I like the Fram TG filtration but the price, even at WM is too much. And the internal construction and filter loading (with this fine filtration) would make me concerned for really long OCIs.

If I was doing 3-4K OCI I would just just about anything in non-critical app. Even if the was no media or completely in bypass, a clean engine would likely survive in good health.

 

[schwartr88]

My mileage varies since I am in college. I can do 12-25k miles per year. I know 3-4k OCIs may be a waste, but it has been ingrained in my head because it was necessary for my last few cars which have been beaters.
I see your point about the condition of the engine at 250k miles being good or bad ect, and probably any filter will get my truck to 250k
Anyways, I guess what I really want to know is will the condition of the engine be better/worse/same using a ST (or other cheaper filter) vs. a P1 (or comparable) filter.

 

[Gary Allan]

Well, I'd say that it would be in better condition ..but whether it will mean any lost utility is unknown. Those who use upper tier filters pay a small insurance premium that's sorta like a bet. They're saying that they can keep it long enough to justify the extra cash. They're betting that something else isn't going to take the vehicle out of service before they can get the added costs realized in avoided loss of service.

You'll do fine with what you're doing. If I were in your shoes, I'd go the upper tier filter and change it every other time. There's no way, outside of some real lame fuel management issue, that you're loading a filter in the short OCI's that you're doing. I'd also attempt to work on breaking out of the 3-4k prison. 6k/4m would (which ever comes first) probably work for your varied mileage without too much shock or trauma to your peace of mind.

 

[schwartr88]

Yep, I may just have to go cold-turkey and double my OCI's. Thanks for the info.