HMMM, let's see FISH sure knows a lot about AMZ/OIL and CUMMINS.
AMZ/OIL basically started this trend to Synthetics back in the early 70's. You may not like their "pyramid" sales platform but they do sell QUALITY highly recommended and tested products. Talk to anyone in the Snowmobile industry just for one. When Blackstone Labs says keep running my 15-40 Diesel Marine Oil with 10K on it for at least another 3K THEY have no idea what they are talking about right? The TBN had plenty of life. Just running the FleetGuard Stratapore filter and NO BiPass filter. This was in my 98 12V Cummins.