I can tell you as a full time mechanic and part time driver in the oil field, my first choice would be a glider and my second choice would be an isx deleted. After those two choices, I would just find a different occupation. The government, who is the biggest polluter, says you must have a system that doesn't actually make the environment better. Then they exempt themselves from it because of its poor reliability. I ask some cummins reps what they were doing to fight the EPA and they said "nothing". Dealerships make a killing from these flawed systems. Maxxforce, paccar, newer detroits are all terrible designs in my opinion. The best and simplest approach I have seen for reducing emissions is a diesel with propane injection when under boost.