Help me understand why wire backing makes a filter better. I thought the metal or nylon center tube/cage provides the required support of the media.
If you read the pinned filter media thread, synthetic media isn't rigid like cellulose/blend media, so it needs something to add structure, which is a mesh backing, either made of wire or polymer. The OG Ultra and most of the other non-Purolator filters use a wire screen. This screen is potted to the end cap material along with the media, keeping it in place. This encircles the centre tube.
Cellulose/blend media is either potted to metal end caps or bonded to fibre ones. In either instance, it's not backed with anything rigid and simply encircles the centre tube. This means that this media can deflect if exposed to considerable dP, particularly if there are large gaps in the pleat spacing, which we saw with Purolator, lending themselves to tearing.
Of course another issue with cellulose/blend media is that it absorbs moisture, which also causes distortion, so if you already have distorted pleats from water uptake, this may increase the likelihood of a tear at a wide pleat space under significant dP.
Synthetic media, held firmly in place by the co-potted screen, and not absorbing moisture, has never, in any of the filter tear-downs on this site, shown to deflect or tear.