Driving some hills and flat around 55 mph mine at the pump got right at 24 mpg. its a 6.5td 95 heavy half 4x4 stock with 4l80 auto 3:73 gears. its at 298,xxx miles. the truck has always got great mileage. it pulls well has been a everyday driver for a few years. in town I would guess around 18 mpg.