Took my 2017 Eco crew cab 4x4 3.92 rear into the dealership for my second oil change at 17K+. I love my Ecodiesel and really have no complaints. Service Manager saw me in the building and came out of his office to say hello and chat. He asked if I was happy with the 2017 and how I liked it compared to my 2015 eco crew cab 4x4 3.55 rear traded in. I told him the new truck is great. The 3.92 is noticeable pulling onto the highway especially towing the 34.5 ' Apex TT. I mentioned much lower fuel economy and very light soot on the exhaust tips. At 67K+ the 2015 exhaust tips passed a white glove test. He recommended a PCM and TCM reprogramming. The paperwork shows RRT 18-035 RRT 181905JE for the TCM and RRT 18-036 RRT 181904HF for the PCM. From my understanding a Rapid Response Transmittal (RRT) is a Technical Service Bulletin (TSB) but is of a higher priority or importance than that of a standard TSB. I could not find these numbers on the WWW. Overall fuel economy for 17K+ miles city, Towing and highway is registered on screen as 19.4 avg. 2015 was similar driving and 67K+ miles had 24.5 avg. The avg screen was up to 20.2 by the time I drove home. I will post again as I put more miles on. Anyone hear of these RRT"s? Do you know what they are supposed to fix? I noticed no change in engine or tranny except better fuel economy in run home. PS...I have been running Shell or Mobile diesel in the 2017 as I get better economy that with no name fuel.