I have a 1 ton Ram with the 6.4 and I tow a 10,000LB 5th wheel with it. It tows just fine and I get 8.5-10mpg depending on terrain, headwind/tailwind etc. I replaced a Chevy 3/4 ton with the 6.0 and I got 7.5-8mpg towing a 9,000LB travel trailer I had at the time. So the mileage is a little better. The HP and Torque are a little better but nothing to write home about or add to the hype. It's a good engine. It won't perform as well as a diesel engine but I can do a whole lot more camping with the money I saved going gas over diesel.