to the earlier hate on the DEF systems.... so far from what I've noted. They are a lot better with short trip driving than their predecessor 6.7 models. MPG is probably some of the best I've ever seen, oil change interval is back to being 7K+ miles, and they finally have dual filtration....something they've needed since 03 when the common rail came about. Only downside, the trucks are HUGE! Make my 01 2500 look like a Dakota parked next to them. They like a set of tires about every 30K. 13 and newer are really nice rides! (and NO WAY would I get a stick! 6spd Aisen, or Chrysler trans have been REALLY good)