ISO Question

[DarthDuty]

Since my last post exploded into a huge argument I have a question about the way they test oil filter efficiency (ISO 4548-12)

Purolator states 97.5% @ 20 microns
Microgard (orielly) states 95% @ 29 microns

I dont want to hear about quality of filter, just a simple question as to which of the two is better and why the results differ.

 

[Stewie]

If you don't have a lab to test it, there is no way to tell.

However, tearolator has a much higher flow rate!

 

[ZeeOSix]

97.5% @ 20 microns is obviously better than 95% @ 29 microns ... if there are no tears.

The results differ because they probably have different quality of media.

 

[Kuato]

Purolator filters better according to the statistics you showed, since it filters out smaller particles, as well as a larger percentage of those particles. Different filter media, different testing, or statistical differences could be the reasons for the filters being different.

Oh, and

because this will probably heat up, too.

 

[ZeeOSix]

^^^ If those filter specs are both referencing the ISO 4548-12 test method, then it should be a direct comparison and what makes the difference in performance is the efficiency of the media.

 

[racer12306]

Originally Posted By: ZeeOSix
^^^ If those filter specs are both referencing the ISO 4548-12 test method, then it should be a direct comparison and what makes the difference in performance is the efficiency of the media.


This.

29 micron sounds like a goofy size to use. The point of the ISO test is harmony. Someone isn't actually testing to the standard.

A breakdown of those numbers is:

Purolator: With a 20 micron particle size, the filter catches 97.5% of them. Meaning that 2.5% of the particles pass through.

Microgard: With a 29 micron particle size, the filter catches 95% of them. Meaning that it allows 5% of the larger particle size to pass through.

With that information, the Purolator catches more and smaller particles than the Microgard.

 

[KGMtech]

And if either of them go into bypass mode, they both catch nothing of any particle size up to the diameter of the inflow holes on the filter base.

 

[DarthDuty]

They use the same test, so lets say both filter 95%, my question is, is it better for 95% @ 20 microns or 29 microns?

 

[Sayjac]

^^^^At (@) 20um(microns) being smaller than 29um sized particles being filtered with 95% efficiency is "better". So, 95%@20um better than 95%@29um.

 

[DarthDuty]

^ Perfect. All questions answered with no argument. Thank you all.

 

[steveh]

Originally Posted By: DarthDuty
Since my last post exploded into a huge argument I have a question about the way they test oil filter efficiency (ISO 4548-12)

Purolator states 97.5% @ 20 microns
Microgard (orielly) states 95% @ 29 microns

I dont want to hear about quality of filter, just a simple question as to which of the two is better and why the results differ.
If your using it for the Altima the Purolator is a 40 micron filter.