Not sure what you mean abt our engs being easy on oil. Maybe in regards to sheering and oxidation, but not so sure abt contamination (I.E. soot) which IMHO would be the main concern in regards to internal filter bypass opening.
The Amsoil set-up looks a lot like what I was thinking about but after reading the description, it appears one filter cleans ~10% and the other filter cleans the remaining ~90% (on a single pass). However, with more total square inches of media it should help prevent internal filter bypass from opening. I still tend to believe 2 regular filters would go a little longer before bypassing, but there's still some unknown variables comparing the two set-ups.
Not sure what to think abt the PPE centrifuge set-up. It's not clear to me if that replaces the OEM filter, or works in series/parallel with OEM filter. Also not clear if it even incorporates an internal bypass valve.
That 100nm filtration level they advertise may also wind up removing the beneficial additives the oil manuf added??
On the amsoil setup, the high flow filter is there as a standard oil filter to catch the ball bearings. Then the 10% thats drawn off through the other filter does a very fine screening to remove soot and other particulates too small for the high flow filter to clean. adding 2 high flow filters would give you less clean oil (though theoretically longer service life of the filters) then running the amsoil kit. There are guys running this kit that say there oil comes out oil colored instead of black at 10K miles. Not sure i buy that, but that filter will do significantly more to clean the oil then doubling up on factory filters. Also, your oil change interval increases greatly as the soot load in the oil is removed by the bypass filter.
The PPE kit is similar but instead of a filter it spins the oil at high speed and the particulates collect in the bowl to be scraped out later. This is an old design thats been around a LONG time and it does work, though personally i think id rather have the amsoil setup so theres not yet another thing on top of my engine.
I am getting suspicious that this whole discussion about substituting all manner of modifications to the stock AC oil filter is just a "solution in search of a problem".
We have ample evidence that many after-market oil filters are sub-standard - I certainly wouldn't want to use anything but a GM/Delco/AC filter, either for fuel or oil. At least not at the "consumer grade" level. As others have repeatedly noted, many Duramax motors have gone many hundreds of thousands of miles without oil or fuel related troubles, on "bone stock" service parts.
I am still trying to figure out if I threw my money away by following the suggestion of some in here to go to a "commercial grade" oil filter, such as the Donaldson DBL 7483, or the CAT 1R-1807. ( I personally bought the 'kit" including the nipple adapter and a filter from MDDP ).
And I have not yet found a DIRECT comparison between the above two commercial grade filters.
What I have found is that my engine oil is now remaining clean-looking even after thousands of miles.
I cant discuss WHY that is the case, for fear that the way I have "serviced" my truck recently, I will be singled out for the wholesale murder of billions of cute little fuzzy-chinned bunny wabbets, and held personally responsible for the coming termination of human life here on Planet Earth in ten years......
The two filter setups that i posted are different in function from the filter mod that bob has covered, and that was linked above in this thread.
The filter systems that i linked are designed to remove contamination that would pass through a standard oil filter with ease.
The problem though is that were you to put in a filter the size of ours with a low enough micron rating to catch these particles you would lose flow rate, and clog filters very fast. To allow for a long service life on the filters, and to allow for full oil flow, amsoils kit runs all the oil through the regular style filter that would normally be on our trucks, and takes 10% of that flow and runs it though a low flow high filtration system to scrub that 10% clean. Over time, all the oil in the pan goes through the bypass filter cleaning the soot and other small contaminants out.
The filter you have that bob did the write up for has a similar benefit, though not be design. That filter has a lower micron rating then what would come on our trucks, so oil will flow through it slower, however due to the significantly larger filter media size, you still maintain correct flow rates through a more restrictive filter element getting a kind of "best of both worlds" setup. While the amsoil kit would do a better job cleaning the oil then your filter, its more expensive and requires 2 filters. This is why your oil is staying cleaner longer.
The PPE system installs in addition to the factory filter and performs a similar function to the bypass filter in the amsoil kit.