When do you shift gears in 9 speed kw semi truck?

It depends on the engine, but if I had a nine-speed in my truck I'd shift up at 1500rpm and down at 1100. But I gotta tell you, I've got a Fuller UltraShift two-pedal automatic and I will NEVER go back to a manual. If you are driving through Port Elizabeth, New Jersey, or downtown Chicago, just to name two of the more entertaining places to take 73 feet of rolling death, and you are trying to get to your destination without bending your truck, running over someone's car, or killing anyone, not having the transmission be on the list of things you need to worry about is really comforting.