Here is the Ecore test I promised, along with some notes on the Wix observations.
The picture below is representative of several comparison tests that kept coming of the same way.
Left to right: Ecore PF-53 IIRC, Mobil 1 Extended Performance M1-102, WIX 51348, and Denso (Toyota OEM 90915-YZZD1).
They are all for the same application.
The Ecore always does pretty well in the comparisons with it's published efficiency of 96% single pass at 15-20 microns and 94% mutipass at 20 microns.
The Mobil 1 always tests for me as one of the better filters for filtration, and is about the same as the K&Ns I've tested. This (the M1) is advertised at 99.2% mutipass efficiency but without a micron size given. Champion Labs however told me by phone that it was about a 10 micron nominal filter (50% at 10 microns), which is pretty respectable and the results show it. It does not test as good as the PureOne, but it isn't all that far behind it either.
The WIX efficiency for this particular filter is not spectacular, showing a 21 microm nominal rating, but in practice, always filters about as well as the M1.
Does this meant the M1 filters worse than expected, or the Wix filters better than expected in the real world?
Since the M1
consistently meets or beats any number of filters with good published efficiencies, and it not far behind the PureOne, I have to go with the weight of evidence that the Wix filters better than expected and that the Wix published ratings are conservative.
The are in fact a lot of variables in how the SAE tests are done, and so published ratings vary.
The Wix, may lose some of this efficiency after it has been in use for a while and may appear closer to the conservative published ratings--but the media is obviously stopping fine debris as well as higher rated filters. This is also evident in that the flow rate in the oil in the test with similar media surface area is about the same as the M1. This indicates to me that something--either median pore size, or depth of media is probably fairly similar, because they both use a blended media. The other possibility is that the Wix ratings that they published have not been updated in some time as media technology keeps improving.
The Denso flows very fast, and filters decently from past experience--maybe average. It's a good filter, I say, but probably not the best at capturing the smaller particles in the fewest passes.
Pictures of my messy shop. I've done a lot of tests!