The DPF, mainly the ones that don't use urea to regenerate take a bite out of the fuel economy. The most efficient combustions cycles generate oxides of nitrogen, so the compression ratio/boost run at supotimal levels in order to meet emissions standards.
Technology may negate the ill effects of the DPF, but the NOx regs are going to be a tougher problem.
The US market hasn't had a midsized or compact diesel pickup since the late 80's early 90's. The ram 50, S10, luv and isuzu mostly got in the 30's with 80's injection technology. In addition to the emmissions regulations, the US market seems to have had a horsepower war between the manufacturers. It seems as though it's unacceptable to need to downshift going uphill whilst pulling your 35 foot fifth wheel.
