I have a 16 F350 SRW. We are getting about 11 MPG towing (hand calculated.) I'm not overly impressed by this mileage, but not upset either. Without the trailer, I can approach 20, but it will then often go into regeneration. I had an 05 CTD before, and it was a great truck. I've towed with the F350 about 10,000 miles now, and in the past two months, we have done most of the Alaska trip, with grades up to 10%. The engine brake is my favorite feature, and it is amazing. Be sure that you know how to take full advantage of it before you tackle steep grades -- it makes going downhill a pleasure.