Glad to report my new 2012 Ford F-250 ,6.7 PSD ,SuperCab,3.31 rear gear pulled our 40 ft 6 inch Designer Fifthwheel from Indiana to Pine Island ,Fla a total of 1,265 miles averaging 13.7 MPG. The new FORD F-250 with Air Lift air springs towed the 15K+lbs Designer with ease,and was much more...