I have a completely stock CTD 06 3500 DWD. I am pulling a 14K Fiver. Last weekend my wife and a were driving through GA on I-85 with the cc set at 65mph and in tow-haul mode. An 06 F-350 pulled in behind me from an on ramp pulling a fiver that appeared to be the same size as mine. It looked like he matched my speed and set his cc as well. Whenever we would start pulling up a hill I noticed that he would quickly start dropping behind. After about 30 miles he was out of sight. I have 30K on my truck and have not had one single problem with the truck. I have been following the maintenance schedule as directed for towing. I have been averaging about 11. 5 mpg towing and 15. 5 driving to work, about half highway and half stop and go. I almost bought a F-350 and at the last minute I changed my mind, thank goodness! GO DODGE!! CTD