NOx and soot production of inversely related. That was the first reason for the EGR being added to engines. It reduces the peak cylinder temperatures to reduce NOx production and then the SCR cleans up 70-90% of the remaining NOx that are generated. Regens actually generate lots of NOx from my understanding which leads me to believe that is where VW and FCA (and others) have gotten into trouble. It is just not easy to reduce all that NOx when you are burning raw fuel and particles and the engine running. Anyway, I've never seen an official report from anyone (haven't looked too hard, admittedly) as to exactly which operational mode and under what conditions and just how much over the limit these violations were to warrant all the lawsuits and stuff.Hmm, I really liked the idea of multiple injections, didn't know it created so much soot. Sounds like it probably makes for less NOx too. Does the GDE make it run rougher? I love the smoothness of teh engine as I hold the wheel. Even my wife's little mini cooper shakes more at the wheel than the EcoD.
Oh, by the way, the 2016 and onward 3.6L Pentastar gas engines have ERG as well. Well, at least the 2016+ Durangos have it. I assume the RAMs as well. I'm suspicious the Hemi will be getting redesigned in the future or replaced with a V6 turbo similar to Ford's ecoboost.