Bob Hegbloom, Director of Ram Truck Brand and Mike Cairns, Director of Ram Truck Engineering answered questions in an open Google+ Hangout on June 12, 2014. Here's the interview recording, and their most important answers.
This obviously isn't live anymore, but you can re-watch the interview here:
If you don't feel like sitting through the buzzwords, here are the more interesting responses. I'm paraphrashing the answers for brevity, but these responses are the thoughts of Bob Hegbloom and Mike Cairns not myself.
"What kind of real-world fuel economy are these getting?"
- 19 MPG with a 7,000 pound trailer in testing. Hyper-miler customers are claiming they're exceeding 28 MPG.
"Why no V8 Cummins?"
- It was too big and not efficient enough for the half-ton application
"Why no manual transmission?"
- Nobody asked for a manual at any of the interest-generating events/surveys Ram did while developing this truck. Ram is the only automaker in the US that offers heavy-duty manual truck, and it represents 5% of their sales.
"Does it use DEF [Diesel Exhaust Fluid]?"
- Yes, every diesel truck up to Class 6 (very large commercial cabs) need DEF; it's an ammonia-type fluid injected into diesel exhaust streams to cut nitrous oxide emissions. It is meant to be refilled every oil change.
"Does it have a variable-geometry turbo?"
- Yes, intake ports adjust automatically to minimize turbo lag
"Is the Fiat diesel engine a piece of shit?"
- No, we've had good luck with it in the Grand Cherokee for the past year, but if you have trouble all our techs are trained on it and you get a five year/100,000 mile warranty.
"What are the rear differential ratios?"
- Standard is 3.55:1 for maximum fuel economy, a 3.92:1 is optional for better towing at the expense of about half an MPG.
"Electric or mechanical cooling fan?"
- 800 watt electric fan that can operate at variable speed.
"Is Ram going to run this engine for a long time?"
- Yes, EcoDiesel is the future. It's going into the ProMaster Van next as a three-liter I4.