According to the folks at GDE the ecodiesel was designed for use with 15w40, the 5w30 and 5w40 options from ram are almost all for fuel mileage and possibly some for cold start.^ like the local 19.99 oil change place using car grade oil. I wouldn't be surprised if a measurable number of failed engines were from the wrong oil. Would/did FCA oil lab test every failed engine?
My used ram purchase came with fluid changes and new tires. From the delivery I noticed the oil was low and coal black. I sent off a sample and it came back as 15w40. The rear limited slip would chatter on full turns. I changed out the rear end with Royal Purple and the chatter went away. So if a Ram dealership cuts corners, who knows what the 19.99$ oil change place does or doesn't do. A more robust design maybe could function on wrong oil. But the 2nd Gen EcoD may be right on the cusp of design limits and need the correct oil to stay in the green zone. Maybe just one dirty dealership or lazy oil tech could be enough to set the engine up for later failure. Even though I changed the oil out, who knows if the few weeks of driving on 15w40 oil did any damage to the bearings/journal. So far two oil lab test were good.
I think there was an ecodiesel owner that reported sending in the factory fill that came back as a 15w40 from the analyzer too. Wish I could remember where I read that.