I have to say I am very impressed with with this truck! I have a 36 ft fifth wheel camper and packed the truck with all the gear we needed for a 5 day trip and took off to the lake. The 6.7 has so much power and at times I forgot the trailer was on! It easily maintains the speed limit and gets to it with NO PROBLEM. I averaged around 11.5 MPG up and down hills at 70 mph. My 2002 built 7.3 is a great truck and has lasted a LONG time but has nothing on the new 6.7. I cant wait for the next trip!