[Slither]

I tow my 28' enclosed Haulmark trailer with my 2002 F-350 Crew cab dually 4x4 PSD. I'm not sure how much the trailer weighs with the Cobra in it.The truck ran just fine stock. But no, I needed a chip. I installed the programmable Superchip into the computers memory. It helped the power some and increased the mpg slightly. Then, Western Diesel came out with the "shift on the fly" chip. You simply twist the knob located on the dash from "stock", then to "50"hp, then to "75" hp and the last stop is a whopping "100" added ponies. If you use the truck in any other selection than "stock", it messes with the trucks overhead computer. So the only way to check the true mileage is the old fashion "math" way. The more hp you dial in, the hotter the hydro carbons get. The boost will go way up too. It also controls the transmission. Shifts are much crisper. I also added the Western Diesel complete exhaust system from the motor all the way back. I also tow a 3800 lb. boat and trailer and the truck doesn't even break a sweat. The advantage is to crank it up for inclines and turn it down for cruising the flatlands. Good luck!