[cleatus12r]

Ah, young grasshopper, you have much to learn.

In all seriousness though, the manner in which a diesel engine operates lends itself to the answering of your question.

As more fuel is added to a diesel engine to make more power, more heat is produced. This heat, if left to exceed 1250 degrees for an extended time (I'll throw out 20-30 seconds if it's much above 1250 degrees), will cause damage to the engine in the form of melted pistons. To make more power, we need more fuel.........more fuel equals more heat.

Towing programs limit the horsepower output to allow extra power but also to limit the heat. Towing heavy requires a good bit of fuel.....but too much fuel also makes too much heat and the chance of meltdown is increased.

Another problem with towing heavy and high horsepower increases comes into play with the physical limitations of the transmission, driveshaft u-joints, and rear differential. The drivetrain of the truck was designed to accomodate a certain amount of constant-duty torque. If you start towing 15,000 lbs.up a mountain pass with an extra 200 ft. lbs. of torque, you will do damage eventually since the drivetrain does have limits. They just are not designed for that kind of constant-duty use. Besides, trying to keep your exhaust gas temperature below 1250 degrees is going to be really tough with 100 HP worth of extra fuel going into the engine.

Keep in mind that you're not ALWAYS pushing an extra 100 HP through the drivetrain since the truck will maintain 75 MPH with the same HP output as stock while running empty.