Is it safe to downshift an automatic transmission while going downhill to control speed? Because there is this hill that I go down often, and there is a traffic signal at the bottom. If you hold the brake down the hill, you have to press down the brake pedal harder and harder just to maintain the same speed. If I shift from D to D3, then the speed stays under control and I am only going 5mph faster at the bottom of the hill. If the light is red, then I can shift into 2 and the RPM only goes up to 4000, and I don't have to hit the brakes until I get to ~20mph. My question is, as long as you don't over rev the engine, will it harm the car to downshift manually in an automatic transmission?

No, shouldn't harm anything, as the 1 and 2 (up to 3 on your car?) positions are specificially designed for that (using the lower gears to get up a hill or use engine braking not to fry your footbrakes going down the hill)...

As above. Those gears are for the control you require to drive. Without them you'd never be able to drive up hill and would need new brake pads every other week. As long as you don't over rev there is no danger. Though don't forget you did it and try changing gears. ^^;

no, thats why you can select other gears.

What is point of automatic if you shift gears manually ? I would not touch it, not because damage, but because if I would have automatic box then I would require it to do it's job automatically

Well just think about why some vibrating dildos have several pace settings

it saves the effort of having do it "manually" but with just one speed it's not going to suit different......."stages" of the experience perfectly.

Quote from JTbo :

What is point of automatic if you shift gears manually ? I would not touch it, not because damage, but because if I would have automatic box then I would require it to do it's job automatically

You slap it in D to drive around town and such, but some times the computer doesn't know what to do, so you need the ability to say "do this stupid computer"

Quote from P5YcHoM4N :

You slap it in D to drive around town and such, but some times the computer doesn't know what to do, so you need the ability to say "do this stupid computer"

Rofl. Thats a funny, yet quite accurate way of putting it

Quote from wheel4hummer :

Is it safe to downshift an automatic transmission while going downhill to control speed? Because there is this hill that I go down often, and there is a traffic signal at the bottom. If you hold the brake down the hill, you have to press down the brake pedal harder and harder just to maintain the same speed. If I shift from D to D3, then the speed stays under control and I am only going 5mph faster at the bottom of the hill. If the light is red, then I can shift into 2 and the RPM only goes up to 4000, and I don't have to hit the brakes until I get to ~20mph. My question is, as long as you don't over rev the engine, will it harm the car to downshift manually in an automatic transmission?

To answer your question, it is ok to downshift an automatic transmission. I do it all the time when I go down a hill, I just put it in 3rd gear (my car has 4 gears in total). It works like a charm. Some cars may not have 1,2,3 on the shifter, mine has only 1 and 2, but it also has a switch that says "O/D Off", meaning "overdrive off", overdrive means 4th gear. I frequently shift from 4th to 3rd to 2nd and to 1st, and so far I have had no problems with my transmission (my car has over 200,000 km on it, that's a Corolla for you!).

Quote from P5YcHoM4N :

You slap it in D to drive around town and such, but some times the computer doesn't know what to do, so you need the ability to say "do this stupid computer"

What computer? Car should not have a computer
If there is computer controlling box, then car is too new and need to be crushed, Replace with something more proper means of transportation, that has not so much computers

Quote from JTbo :

If there is computer controlling box, then car is too new and need to be crushed, Replace with something more proper means of transportation, that has not so much computers

Automatic transmissions have been electronically controlled since the early 1990s. It's much better then a mechanically controlled automatic transmission for driving around on the street. If you are in a dragster, then a mechanical-controlled transmission would be better because there are no sensors to go bad.

Quote from wheel4hummer :

Automatic transmissions have been electronically controlled since the early 1990s. It's much better then a mechanically controlled automatic transmission for driving around on the street. If you are in a dragster, then a mechanical-controlled transmission would be better because there are no sensors to go bad.

They stopped making proper cars around those times

I prefer mechanical auto box, I know exactly what it does and when, with electronically controlled it is not so clear, same goes to throttle too + older vehicles had better engine braking

Its ok to downshift with auto trans. but why the hell would u try to drive it like a stickshift? autotrans was made for gokarting for the lazy americans..

(Jtbo: push that lx4 )

Quote from e2mustang :

(Jtbo: push that lx4 )

Doing my best, but damn neck started to resist, good thing is that back pain is cured

If not today, but tomorrow your time will get trashed