Originally Posted By: caravanmike
... they are extended performance with a higher micron rating (20) than the non xp filter (15).
mike
Those kind of um rates are pretty much worthless. Really does not tell us what we want to know as informed folks. At face value, the non-XP would be "better" with the lower um rating, but since there is no real baseline statement for particle size, beta or ISO ratings, it's basically trash info.
I have seen this kind of manure from Wix previously; allow me a couple of examples.
Several years ago, Wix listed their oil filter for my Dmax at "8 um nominal". I thought - WOW - not bad for a full flow filter. Gary Allan and I discussed in great detail. Then a few years ago, the update the specs and it magically became "20um" on the Wix site. What a bummer, but much more realistic for a nominal rating. Now, they list it (along with about 2/3 of the rest of their white-washed data) at 2/20=6/20. They keep revising their info. I suspect the first "8um" rating was a mistake; the others are market updates and finally white-washed worthless info.
Same goes for the fuel filter for that Dmax engine. Used to be a 33910 filter had 4um (presumed nominal but not actually stated). Then they brought out 33960 (plastic body) and the XE version (upgraded media). However, the "XE" "high efficiency" that was supposed to be a "better" filter with upgarded media, but was rated at 7um while the "normal" filter was still rated at 4um. I emailed them; got a canned boilerplate response of "better is better". After several emails back and forth, they just stopped responding to my question as to how they could publically call a 7um filter "better" than a 4um filter; I asked for ISO data and got snubber. Now, at this point, BOTH are rated at 7um and the 4um rating is gone ...
My point? Few if any of us will ever get real data from the major filter makers. They closely hold that data and don't like to share. And the filter makers are often correcting mistakes, or tweaking products. I think that is is Wix has simply stopped putting up their full beta data, and is now "white washing" all the specs to the 2/20=6/20. They are simply tired of informed folks (or at least wanting to be fully informed) of second guessing their efforts and/or calling out their publised mistakes.
Doesn't mean the Wix XP isn't a good filter; probably is. But it's also probably overkill for most applications. It's a market response to the other premium filters from Bosch, Fram, Puro, Mobil, etc. Most of us will never be able to capitalize on the supposed benefits, because most don't ever even get to the pratical end of a "normal filter" FCI ...
Food for thought.
BTW - if you do to the fleetfilter.com website, you can still find much of the oil filter beta data listed there; the "whitewashed" data hasn't migrated to their site yet. You can also still see the fuel filter ratings I spoke of.