Have a D3 GT FWD (see signature) and travel daily in the mountains and valleys of the Taunus. In order to reduce the brake wear and because it is so easy, I set the selector lever to “manual” at the beginning of the descent and switch down. In order to reduce the speed of the descent I also like to choose a very small gear. So I hardly have to operate the brake. The speed is often very high and the engine noise, let’s say potently. It is built in a limit, so that I can only choose a small gear as the vehicle “wears”. However, since I practice this every day, I am still thinking (the engine jauling doesn’t make any more relaxed) if I can not do anything damage and in the future stand better on the brake. By the way: AWD only has a mountain descent assistance (to get these answers first).