I have been following this debate since the PureOne "tearaolators", where the non-wire backed media would tear, usually close to the end where it was glued. There have been posts of the new non-wire backed Fram Ultras with wavy pleats, insinuating that they, too, might tear. I think
@ZeeOSix has mentioned the increased number of pleats giving it a little more strength avoiding the tearing issues the PureOne had.
I am now wondering about the legitimacy of these claims. When the PureOnes (not to be confused with the current Purolator Ones) were shown torn, I don't remember the poster stating how long it was run, or what grade oil was used. Was it run way over the recommended mileage? Was extremely thick oil used? Was the engine taken to redline on cold starts? Or maybe the bypass valve wasn't reacting fast enough? Hell, maybe the filter didn't have a bypass valve & the engine didn't have one. A lot of this is anecdotal. You may not need a wire screen backing if you don't experience the conditions the engine was subjected to.
I was told by an analyst years ago that if I use the PureOne be sure to change it early, because it will plug up faster. That made sense because a finer filter will load up quickly, simply because it is trapping more material. Now the newer filters boast 99+% @ 20u, yet still advertise high mileage, I'm assuming because full synthetic media can hold more. Remember the PureOne was synthetic/cellulose blend.
I seem to remember the Purolator Boss advertising a higher efficiency at a lower mileage, e.g. 99%@25u for 20,000 miles, but 99%@20u for 10,000 miles (don't remember the exact number, but you get the jist). That would make sense that the higher delta p was sloughing off captured debris. Apparently mfgs sell based on higher mileage to warrant the extra cost. So in that vein, would the Endurance (or Amsoil EAO) be higher rated at say, 15u for less than 25000 miles? The testing done by Ascent was on a new filter, where the OG Ultra was exceptional, but it was new & unloaded. Fram's data I would assume is based on long term use, so some of that captured debris would be released as the delta p increased, causing a lower efficiency rating.
I switched to Endurance (and/or Amsoil EAO) from Ultra simply because of the wire screen. The motorhome regularly sees 4000-4500 RPM bursts but the oil is at operating temp & viscosity, would that be enough to warrant a wire-backed media? The Ultra may in fact have a higher efficiency than the Endurance, & I never take any filter (or oil) beyond 4000 miles.
Edit: I presume the only way to really know would be for me knowing the history to cut one open & take pics. I just might do that after my next Texas trip.