Ok, I'm pretty sure that it's 7000 RPM peak torque. That's not the maximum RPM the engine runs at. It's the torque point for smooth shifting of the gear box for a big old turbo charged diesel engine.
I'm sure you've noticed a truck driver revving the motor on occasion when he's going through the gears.
Swamprat has been doing it long enough to know when to shift by sound and feel. Yeah, we drive by the seat of our pants.
