I have done a lot of tuning on the ram and based on all of the cause and effect observed, I can say that power service will change the ignition delay which is why some report a mpg increase with it. I have seen pics of cylinders & the head from someone (in a cumminsforum thread) where they tore down an engine that lived on 2 stroke and it was pretty damn clean... I can also add that (pot stir time) that a few cummins owners have over 75k miles (285K miles on original injectors iirc) running older spec ATF in the fuel in their CR motors, all with excellent results... (cleaned fuel system really well, I just started and have only ~5k miles with it. Too just 250~300 miles with it to see significant improvements. Non-DPF trucks though ).