AU – Control speed ?

Hello everyone, I was just with the fine dust blower at the Dekra. Result : badge without defects. But : The type has turned the car three times in a row several seconds at a speed of almost 5,000 rpm to determine the AU values. Only : With the diesel starts the red range already at 4,500 rpm – it has thus overturned it several times (!). That he then turned out the engine directly (turbo !) has already not surprised me. I know that a high speed for the values is necessary, but SO much? Clearly in the red area? Is that normal? Greeting Martin