Find it hard to believe HP and torque increases aren't mutually exclusive to MPG increases. I would think that claim for mileage is dependent on driving the thing conservatively which you can do without the chip. Elimination of any excess weight like hitch, tools, etc. and leaving truck stock (i.e. no steps, light steel rims), and slowly accelerating and smooth stops will do more for MPG than any chip. Don't see any information on if it requires premium fuel, which would negate any monetary savings.