So does biodiesel, and I've only ever see a fuel economy IMPROVEMENT, if anything, when running bio. 1-2% is not even noticeable. With the new technology, they should be able to offset any losses with even BIGGER gains. Not using internal EGR like AsSET and ACERT models used (which was really just lots of exhaust backpressure) will help.
As far as increased costs per rig, i've seen the estimates go from several hundred to twenty thousand. I don't think that it will be as much as in the previous post. The DPF system just doesn't cost that much.
So far, everything I've read shows this is much ado about nothing. Maybe a little increased cost up front (maybe a lot, who knows???) but beyond that, I guess I'm not seeing a real big problem.