As noted a few times above, older is better for all of the reasons listed. DEF is a pain in the ass, along with the 20,000 different functions that are now monitored via computer. The emissions regs have choked the diesels way down from their potential. Don't get me wrong, the new trucks are nice, but I find it odd that in the name of cleaner air, which is bullshit by the way with diesels, that they put a huge dent in efficiency, and it's all the manufacturers that are suffering in pickups and the larger engine market. If I was looking at a Dodge I'd find an older 5.9 24 valve and run the shit out of it. The automatic transmissions (48RE) will hold up fine until you really start twisting them with programmers and such.