Good morning BITOG'ers
While I have no plans to publish the capacity of every single FRAM filter part number or style, here is the deal.
1. Oil flow does not drop until the filter is nearly completely full. If your leaving it on that long, you are either using the wrong filter or too much time between OCI's, or your engine is a poorly maintained sludgebucket. You can monitor this if you have a high quality accurate analog oil pressure gauge. Check pressure when filter is new idling, make a note, check again monthly. When the warm engine idle oil pressure starts to drop, the filter is full or close to it.
2. Most all decently maintained modern fuel injected engines with a properly functioning pcv put LESS THAN 1 gram per thousand miles of dirt in the filter.
3. In the PH8a size, the standard orange can of delight holds 11-12 grams, the only reason this filter cannot go 10k miles is the nitrile rubber ADBV (silicone coming in 2017 and EG will be rated to OE recommended change intervals!) The TG8a holds 16-17 grams,The XG8a holds 29-32 (these are averages based on testing). All of these filters are overkill for the change interval on the box regardless of the can size.
The XG with minor improvements will be updated with advertising to 24k between changes (coming late 2017).
None of this means anything without doing the following- Using the best quality oil THAT MEETS OE specifications, checking and adding oil as needed during the life cycle of the OCI. As always, I welcome your questions but is best to contact my work email directly for the fastest response.