The biggest thing with any DPF equipped diesel is to get it up to full operating temp and let it complete DPF regeneration cycles regularly. This is independent of which manufacturer you prefer, they all have DPF, the DPF needs to be run through regen cycles, and the motor has to be @ full temp for some time to do it. It can take 10min+ for the engine to get up to temp during the winter, idling will not bring it up to full temp, idling will get it "Luke-warm" @ best.
I bought my '08 Dodge diesel with 60k miles on it. I didn't know it at the time but it had been DPF deleted. The dealer didn't know it either. It has a chip under the dash with a flashing light. The dealer thought it was some kind of performance chip but I got the numbers off of it and went online to find out what it was. Turned out to be a gizmo that resets the time to the next regen to max every time I start it.
A friend has an '07 identical to mine that has not been deleted. When we're up hunting on the back roads for more than a few days, he has to go find a highway to run it up and get it hot for a regen or it really starts bogging down. It's a real PIA.
