I tow a 13k gooseneck horse trailer on a very regular basis and I average 13 mpg going from Simi Valley to Oak View at least once a week. Thats going over the Camarillo grade each way. Non-towing it gets 17mpg on the hwy. My truck is stone stock and it does everything I want and then some. For me there is no reason to start adding/deleting things that will void my warranty and make my truck non-smog compliant. I'm too old for that nonsense now.