I have a Platinum Reserve with the 5.0 Cummins. About the best fuel mileage I can get is 15 MPG not towing anything. The Dodges get 25 plus and Ford is advertising 30. It's a sweetheart of a truck, very responsive, leans into a load good when towing like you would expect from the Cummins, but it's a fuel hog. Between the lousy fuel mileage and small fuel tank, you're stopping frequently to either add fuel or add DEF!