Originally Posted By: sayjac
^^^ You're entitled to your point of view as I am to mine. I agree with poster's conclusion I quoted. Same phemomenon with similar construction principles, potting designed with adhesion to metal endcap. Same result on both the Denso and topic'd filter regarding specifically the endcap falling off on filter and dissection. As long as leaf or coil spring functioning as designed to securely hold element, no oil bypass. Based on my reading here over the years, that too is the consensus of opinion.
Classic endcap construction is being compared here, ie., metal endcaps, and thus comparison to no endcap design is unrelated/irrelevant to the discussion imo. Different construction type. But since addressed, as has also been shown here many times, no endcap type filters test relatively low in efficiency as compared to majority classic construction filters from major manufacturers. End off topic portion.
The picture of a protrusion that seals the glue on the flat area just around the center tube on the Denso and no protrusion is seen on the Bosch are facts, not opinion. Given the pictures shown here such as they are. The reason that fact applies to mentioning no end cap filters is they also have a sealing indentation ring in the glue around the center tube. That seal is what prevents flow around the media.
Neither the Denso or Bosch end caps look to have been adhered at all to the glue, smooth and clean. My opinion on that is that is probably how they are made, unless these two are special. Maybe, like I said before, the Bosch seals the center tube with the ring that enters the center tube. As far as no end cap filters having low efficiency, I have seen only one professional reference to that, on one brand and model Toyota filter, in Amsoil's graph. That hardly is proof being one test on one filter by a competitor. The end caps obviously have nothing to do with efficiency. The new Denso filters have two ply media, no data on those.
