So I took my 07 G35x (5AT) to a shop today to get the P0011 code fixed. While they were diagnosing it, they had it parked and were revving the engine up in Drive and applying the brakes at the same time so the car doesn't move. Apparently they do it on all the cars and it's a way for them to test the engine under load. Just from logic I think this is very bad for my power train but they said it's fine and doesn't harm anything. Can someone clarify? Thanks

 

No biggie. People do that all the time to do burn outs in autos. I wouldn't make a HABIT of it necessarily, but your cars fine.