I had a rather long conversation with the service manager at Cummins in the Phoenix area a couple months ago and I would guess he would wholeheartedly disagree. He told me DPFs have a limited life span and they have changed out quite a few. This was not specifically due to using the wrong fuel but just because they will eventually wear out. Using the wrong fuel will increase the number of times the DPF cycles which will reduce the life expectancy of the DPF since you can only expect so many cycles over time. Of course neither I nor the Cummins Service Manager would make a claim to being the world's foremost authority. But logic says everything wears out over time. If you put 500ppm fuel into a system designed for 15ppm fuel common sense should tell you the system will have to burn that substance off more often - more burns = shorter life. Just how much more cycles might limit life is probably debatable. The Cummins guy told me all the DPFs wear out and the more you use it the sooner it will wear out - he says they replace them on trucks all the time. I didn't go look this up just now but I have heard a new DPF for a Cummins can run around $5,000. I would suppose there are variables as to how many cycles a system can handle. An owner's decision might come down to how much they have in their maintenance budget and how soon they are prepared to pay for predictable repairs.
