Originally Posted By: Merkava_4
... Efficiency is nice to have, but if the filter completely collapses in on itself and blocks the flow of oil, then efficiency isn't going to do you much good when there's no oil flowing to the engine.
At least in the case of cartridges for my car ...
In the no-end-cap Toyota (Denso) filter, the inside diameter of the media fits reasonably closely around the center tube of the filter cap, so that that tube prevents "the filter collapsing in on itself," just like the center tube in a spin-on filter. In aftermarket replacements I've seen with end caps, there's more radial clearance between the media and the center tube, so the media hypothetically could crush inward more. Some makes and models have a wider gap than others. That said, I used one with a relatively large gap, and it did not collapse at all. Anyway, better support against inward collapse looks to be an advantage of the no-end-cap type.