Just some interesting specs I discovered today while browsing filters,,,
The small 'OEM recommended' Wix (part # 57060) for the late model 4th Gens flows 10-12 GPM
The larger ''OEM recommended' Wix (part # 57899) for the earlier model 4th Gens flows 9-11 GPM.
The larger still Wix 'PH8A equivalent' (part # 51515) that would fit the filter relocation kit in this thread flows 7-9 GPM.
WIX Filters - Products Catalog Home
I did find (1) relocation kit manufacturer that has a 'deluxe' version that 'retains the use of the stock oil filter':
http://shop.perma-cool.com/Engine-Oil-Filter-Relocation-Kits-DELUXE-single_c20.htm
Part number for our Rams (single filter) would be 70988
http://www.summitracing.com/parts/prm-70988
Part number for our Rams (dual filter) would be 72988
http://www.summitracing.com/parts/prm-72988
Several ways to look at all this,,,,,,
Would a dual remote filter set up with the 'PH8A' 3/4" Wix filters have a combined filter flow rate twice that of a single 'PH8A' Wix filter, surpassing that of the original small 'OEM' Wix filter in late model 4th Gens? My farmboy math says they should, barring any other bottlenecks in the system.
Would a dual remote filter set up with the small 'OEM equivalent 22M X 1.5" Wix filters have the highest flow rate possible of the filters listed above? My farmboy math says 'yep, barring any other bottleneck in the system.'
Would a single remote filter set up with the 'PH8A' 3/4" Wix filter have a flow rate less than either the large or small 'OEM' Wix filters,, with or without any other bottlenecks? My farmboy cipherin' based on the Wix website sez,, 'Sure looks like a distinct possibilty',,
I think the OP did a GREAT job of writing all this up, and it's clear he didn't use a 'Wix PH8A equivalent' filter. (He utilized a Royal P 20-253)
I have no flow data on his choice of filter, and I'm certainly not condemning anything he's done. Not at all.
But,,,
if flow rates matter to folks,,, please be advised there are some 3/4" filters out there made by a reputable company (and potentially others) that do not meet the flow rates of what that same reputable company (and potentially others) would have you install on your 4th Gen RAM.
(On a sidenote,,,, Does anybody have flow rate numbers for each individual RP filter?)