X15 down on fuel economy recently?

[JimT]

Well, I'm not the expert Rawze is here, but based on the info you presented I'd be less concerned about the DPF/DOC at the moment and more focused on the engine and the exhaust stream. Burning oil, coolant, excess soot or just anything out of the ordinary. Regens seem to be very consistent every 100 hours or so, max temps are all about equal, but max differential pressure has been going up each time. The increased ash load could just be from normal regens, or it could be the result of contaminated exhaust. Baking the DPF should lower the ash level but if there's something in the exhaust causing the problem then you'll just work your way right back to where you are now. I believe Rawze has said that there's only so many times they can be baked before they loose their effectiveness.

Anyway, just my 2 cents