[Big Dave]

My problem with the DPF is four-fold.

Any filter induces back pressure. Turbo-diesel efficiency is VERY sensitive to back pressure. Back pressure reduces MPG.

The DPF uses fuel to burn off the collected graphite dust and convert it to CO2 with nothing gained. At least a coal-fired power plant (coal is mostly graphite) produces useful power. The DPF wastes fuel and produces CO2 for no good reason.

DPFs are very expensive. The DPF for a pickup truck costs $4,500 - dealers cost. This imposes a cost premium over gas engines.

It is not needed. The air quality in the US is the best in living memory. The Tier II standards(of which the DPF is) will not produce any noticeable improvement.

In short the DPF is the work of the devil.