I would not let the resale of a tractor equipped with DPF worry me. I believe if a particular engine is having issues with the DPF or the DPF is to costly to repair, American ingenuity will come up with a way to delete it. They are doing it left and right in the over the road trucking and light truck. And as far as I know it is going unchecked, most inspections are visual they reflash the ecm and core out the DPF. One of two things are going to happen. The larger trucking companies which have to leave the DPF on and functioning are not going to be able to compete with the smaller companies from a pricing perspective, and the larger companies are going to throw the smaller ones under the bus. The the EPA is going to have a choice say we messed up and it is ok to take the DPF off, or they are going to have to go after the little guy. Now if you go back and read what I have been saying in this thread, you should be doing some real head scratching!