I have a 2007 F350 Im only getting 10mpg hwy and I don't know why. I have changed all fule and oil filters and replaced Turbo Hose? Any help would be great

. Use full synthetic lubricants in the engine, transmission, differential(s), power steering, and transfer boxes. This should increase fuel mileage by 8 to 10%. Beyond that, there's not a whole lot you can do. Mileage always drops in the cold, winter months.

. Ensure the air filter has been recently changed.

. Check for dragging brakes, including emergency brake.

. Check tire pressure.

. Check the thermostat.

. Install an engine block heater.