Diesel engines, for all their rugged usefulness, can be tremendously polluting. They produce more NOx — nitrogen oxides-based emissions – than gasoline-fed cars, as well as more particulates, aka soot ...

If you ever want to start an argument between diesel enthusiasts, just bring up the topic of the 6.7 Cummins and PowerStroke diesel engines and see the sparks fly. It's a rivalry as old as time itself ...