I've driven auto-trans car for a while but only till these days I start trying gear 3 and 2.
I was driving on mountain roads in Mount Rushmore and Yellowstone. Switching from gear D to 3 or 2 will make going up-slope and down- slope much easier.
However I'm not sure whether I can keep doing these while driving without damaging my engine. For example when the car was at 60miles/ hour going down-slope, I switched from gear D to 3 or 2 to get better control of the car. I also sometimes drive at gear 3 for a long time even on straight road at speed 60-65.
Another dumb question is will using lower gear especially for down- slope save the brake? It looks like the speed limit of lower gears can control the car without requiring constant braking.
Thanks!