Hey everyone I am new to the forum world as well as the diesel world. I just bought a 2010 2500 4x4 Leramie in october and want to find out the best way to increase fuel mileage and HP. I am not looking to rip the rear tires off the truck just modest HP increase and mileage. It sounds like any thing i do to the truck can void the warranty depending on the mood of the dealership. I am looking to do an cold air intake and tuner i am just not certain which are the best choices. Is there more i can do on top of the intake and tuner? thanks for the help.