It is also not good to generalize and say these engines are overworked in Rams when they actually have a very good reputation in every platform in which they are used.Singling out these single examples of durability are not really good examples. There are plenty of Priuses that also went 300K+ on their original hybrid battery as well. But these high-mileage examples in fleet vehicles are not representative of the typical driver. Failure patterns can be very different.
It is an outstanding engine with an industry wide reputation for reliability and durability in every application in which it is used.
But a weak overstressed engine is not going to go 625k in any commercial application. So I think it is a very good example, given the statement to which I was responding.