I looked real hard at the Ram and Fords before I made my purchase 2 weeks ago. GM didnt enter my equation simply because they have an outdated interior and smaller cab (im 6'5"), but they have a great engine tranny combo. As far as mpgs they are all in the same ball park now since Ram went to DEF. They used to be much worse when driving unloaded. I ended up going with Ford simply because they made the best deal. I would have been happy with either one. My current MPGs when driving unloaded 55-60 mph is around 17 and when i was on the interstate doing 75 this weekend i was at 15.7. I have found that this dually is about .5 mpg higher on the computer than hand calculated. Just trying to give you an idea of my mpg but all the big 3 should be pretty close. Find the truck you like and the best deal and go for it.