One of the best trucks I've owned. Was looking at another brand until someone told me how good the fuel mileage was with this truck. Somewhere around 18 to 20 mpg highway driving. The 6.6 Duramax diesel/6speed Allision trans is one awesome drive train. Plenty of power to spare. Shifting is very smooth. Interior comfort is excellent. The dual zone auto temp. control, leather power bucket seats keeps comfort at the front in this vehicle.I would highly recommend this truck to anyone wanting muscle and comfort.