jdecampo... My brother inlaw has a 6. 5turbo , when we travel together towing our 5th wheels ( both 31foot ) I have to stay in front on the hills , his slows down to much when the grades exeed 4% , I have yet to hit a hill that I cannot maintain 60mph . This is where we separate the boy motors from the men motors. Nothing against his chevy , Its a great truck just a little of its league