Originally Posted By: Camprunner
Would a wire backed filter media like a Fram Ultra for example have an advantage as far as flow rate where the filter media would be less compressed in the filter allowing the oil to have less flow restriction?
I am going to dissent here ...
Generally, no. At least not to a point where your engine would ever know any difference. Technically, for any given media density, there may exist a small advantage, but not in a manner that you infer.
You cannot ignore the relationship of flow to pressure (delta P) across the media. There isn't any real difference between dP for most filters during normal use, and so the flow isn't going to be appreciably different either. I say this in context of comparing/contrasting a FU to TG for example, as they have the same efficiency rating.
What most folks don't understand is that these premium filters (FU, XP, etc) don't really get you "better" performance specs, but they do offer LONGER performance durations. Great example is the TG and FU from Fram. Both rated at 99%, but the FU is rated for 50% more use (more holding capacity of contaminants). So, for any given loading of the media, the dP will be about the same, and therefore the flow will be about the same, relative to the OCI. Only if the media were nearly 100% loaded, would the bypass open, and then flow would balance via the variable spring pressure ...
In fact, a lessor efficient filter would, in theory, perhaps offer less dP, and therefore more flow. For example, perhaps the EG would flow more than the FU; 95% to 99%. I cannot prove this nor do I have any basis other than a hunch. Certainly, when looking at lower efficient filter such as OEM Toyota or Honda, they certainly "flow" a lot because they are not very efficient at all. Does that stop engines from running? Nope.
Here's the thing to understand:
Generally, nearly any filter made for a full flow application used in a traditional positive displacement oil flow system has probably 2x more flow capability than the pump could put out. Even a lowly dreaded cellulose filter can flow way more oil than your engine is going to push. Since these filters flow WAY more than the engine will deliver, how much one flows relative to another is completely moot dribble that only we BITOGers noodle over. It just has no practical concern in the real world.
Most filter makers don't publish data, but Wix does. And all their filters are rated at the same flow for the given application of individual filter.
Some of you "worry" (fret, ponder, mull, ...) over things that just have no real world tangible effect. Whether or not the FU "flows" more over some other alternative is pointless. All filters flow way more than the engine will deliver.