I also think that emission controlled diesels are a waste of space. Diesel motors get all corked up with all that crap. Look at Volkswagen. The new programming that they have implemented to tighten up the emissions have dropped efficiency (fuel mileage) by 20+% on most models.
ANYWAYS, before I get too far off topic, thanks for all the help and I'm now looking into those Timbrens. It's a solid idea (no pun intended) and I really like the simplicity of the system.
The VW thing makes me laugh. They probably got 20% cleaner with the new tune, at the cost of consuming 20% more fuel to do it. Net gain for the environment? ZERO. Net gain for "big oil"? Sales to TDI owners up 20%. Net loss for John Q Public? 20% added to their fuel bill.
I am driving a 2014 Ram 3500 Cummins these days (came from a '98 12 valve). Fuel economy is about the same. I have to say, as much as I hate the EGR etc, that the system on my truck has been no issue. I can get almost 20 mpg out of a modified 8500 lb truck if I drive it smooth and steady at 65. That's great in my opinion. With my camper on, I only get 11-12, but it is close to 4000 pounds wet, and has a high cabover. I just factory ordered a Northern Lite 9-6 Classic which I'm hoping saves me 5-600 lbs, and maybe gains a couple of mpgs through better aerodynamics.
I'm running Airlift bags and Torklift "Stable Loads". I like both products, but haven't tried Timbrens yet. Maybe some day.