cevans wrote:
First off, there is no "water separator" in our fuel filters, period. The only thing that exists is a drain at the bottom of our filters, which can be used to check and/or drain settled water. There is no magic mechanism or filter media inside a 30 dollar filter that can separate the water molecules from the rest of the fuel and deposit them neatly in the drainage area. Water accumulates at the bottom because it settles there. There is barely ANY flow through the filter, so, heavier objects settle to the bottom. (also why ON's filter was only 1/3 dirty, the visible crap just settled toward the bottom)
As many people have attested and I too can share their experience, proper fuel almost guarantees you will never have water settling inside your fuel filter. Secondly, as mentioned, if your fuel is that contaminated, a fuel filter isn't going to save your engine.
Now, back to the magical water separator. The CAT filter will do EXACTLY the same thing as the OEM filter: allow water to settle at the bottom. You will loose the ability to drain the filter. However, fromm y viewpoint, draining the filter of non-existant water is pretty much futile. At point where there might be less than a drop of water could be at 40,000 miles, at which point, I'm assuming, we'd be changing our filters anyway...so, for me, the drain at the bottom (or the misnomer "water separator") is useless.
On the other hand, the CAT is much cheaper than the VW OEM alternative, and when I switched to it, was 12 bucks a pop. Not as cheap anymore, clearly, but still better than a $30+ fuel filter from VW. I'm not entirely sure the extra filtration is necessary, but it definitely isn't going to hurt anything.
Its a great filter, for sure, CAT makes the best. Personal opinion wether it will make any difference, but don't kid yourself that the CAT filter is missing a "feature" that the OEM has.
But it is missing a "feature"..it doesn't have an attachment for the WIF light. Fuel source with Diesel has always been a little bit of an issue. More so in remote areas...but if the light comes on, then you drain the water, then it comes back on, then one would question the fuel source. It might settle to the bottom of the CAT filter, but what indication do you have that it is or isn't present? At least with the factory filter you have some type of "heads-up" that water is there.
I am not just going to assume that everyone who has handled the fuel before it is put in my tank did so properly. I prefer not to fly by the seat of my pants

especially since basically everyone I deal with these day is incompetent at their job....it is refreshing to visit these boards and see that there are still intelligent people out there in the world.