Quote Originally Posted by magicniner View Post
The whole point of an Impact Driver Mechanism is that it isn't reliant on motor torque, it releases the drive in response to pre-settable torque demand, allowing the spindle to accelerate, it then uses spindle system angular momentum against a braking mass to apply the required torque, repeatedly.
That's true when tightening but loosening is a different matter as the spindle will be stationary.