I am going to install the Quadzilla DXZT on my 2004 Dodge 2500 4x4 Diesel. My question is have any of you guys installed one on a like truck and did you notice any increase in Fuel economy. The HP increase is fixed at 60 hp and the Torque is fixed at 120 Ft Lbs increase. I tow a 12,000 lb 5th wheel trailer. Thanks .