I've been curious to know what the 3 2 1 are actually there for. It doesn't seem right to use them in an automatic car without risking damage to anything. I guess my question is if you use them for engine breaking, will it damage the vehicle in anyway? I've read things that say, they're there for a reason, but others say that you shouldn't use it.
My car has 54000 miles.
My car has an automatic transmission.
They are there for a reason. The transmission is controlled by a computer. It will not let you cause damage. You have to look at it from a perspective that it’s there to prevent shifts, and not to force a shift.
For example, if you are driving in hilly terrain, using position 3 will prevent the transmission from bouncing back and forth from 3 to 4, and back to 3. If you are in stop and go traffic, using 2 will help you brake and prevent 1,2,3...3,2,1 over and over.
Using 1 to descend a steep grade in snowy conditions is the best way to maintain control, better than any ABS. Engine braking will not hurt your drivetrain. It is a natural occurrence if you have ever driven a car with a manual transmission.
Automatics disengage engine braking in 4th to let the car coast for better fuel economy, but it doesn’t make sense if you have to ride the brakes. If you are cruising at a steady 45 mph or higher, use 4, (drive). You will have to experiment with your car to see what feels right under the conditions that you are driving. Your owner’s manual will also give you information specific to your car.