Hate to bump this thread, But im curious if you have done any more samples... Thats very impressive 22k miles at 23ppm iron. Is cost of amsoil worth it...thats debatable. But Highend oil shows well here. But like Dnewton said we really dont know how this engine would run on delvac at 20k miles it may be just really good wearing engine.
I think we can all Agree here maybe this engine is a unicorn in wear rates but 1ppm iron per 1k miles is most likely due to this oil and not just good engine, I personally have not seen dmax run numbers like that on dino.
In my Dmax on 10w-30 dino: https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3519069/1
Routinely at/under 2ppm/1k miles, even when flogged hard
pulling the RV in the Rockies (EGTs maxed out for minutes on end running uphill).
while admittedly a bit off course, I can show you where 10k miles on dino PCMO related to 1ppm/1k miles. And I mean really inexpensive, Rural King brand dino PCMO:https://www.bobistheoilguy.com/foru...22/5/5w-20-ford-4-6l-engines-uoa-testing
In fact, every single 10k mile OCi was at or below 1ppm/1k miles; it wasn't a fluke. It was ALL of them.
Generally the wear rate is innate in the engine and the lube chosen really does not greatly affect the wear rates.
the Dmax is one of the best wearing light-duty diesel engines, as the 4.6L mod motor is for gas applications.