^That was a fantastic read. Personally, I've identified the Opti-Lube summer (4th place) as the cost/performance sweet spot and that's what I'll be trying going forward.
Anecdotally, I spent the first decade of my adult life as a metallurgist at Allied Signal, and worked below a chem lab, so I find tests like this to be fascinating and highly informative. Thank you. Additionally, my father was an engineer too, and introduced me to diesels when he brought home a new 1984 3/4-ton Suburban with a 6.2L N/A diesel. That one lasted nearly 300K miles towing horse trailers interstate to horse shows. It was retired in 1992 and sold around 1998. The reason it was retired is because it got replaced by a 1992 Dodge Cummins intercooled turbo diesel (he raved about the new intercooling), which was the primary horse hauler until 2010. Dad was a big proponent of diesel additives. He'd occasionally run a slug through to clear out water and clear the injectors. Our rigs lasted decades, and as a result I'm a believer in proper additives.
I found many of the posts in this thread helpful. But honestly, this one grabbed my attention. I trust the guy that bought a diesel 'burban back when the rest of the U.S. auto industry was in tatters.
My 1st Dodge. Long time admirer.
2019 Laramie 3500 6.7 HO Aisin AS69RC. Borg Wagner 44-48 4x4. Crew cab/8' box. Single Rear Wheel. Max Steel. 295/70/18 (35x12) Mickey Thompson MTZ P3. No lift/no level.