Just bought a Dodge Ram 2500 Diesel 6.7 and I'm confused

wanderingbob wrote:
I never use tow-haul unless in hills , I have same truck. Always use e brake unless extremely slippery . The plus and minus button , I have used it only going down big hills in mountains .

This is foolish. When loaded you want to run tow haul. Your converter will end up locked earlier and generate much less heat, as well as lockup occurring in a lower gear will result in less shock to the trans and drivetrain when the converter locks.