Downshifting in an Automatic - Toyota Nation Forum : Toyota Car and Truck Forums

Frankenstipe · 02-12-2007, 04:01 PM

I often make trips from Northern California to the Central Valley to visit my family and on alot of the turns you need to slow down before completing the turn. Well I can't explain it but I just do not like using the breaks when driving on the freeway/highway. So often I will turn off overdrive and that will be enough to slow me down enough to make it safely and comfortably around the corner. On some of them I will downshift to 2nd for faster breaking power. I notice that my RPM's usually go into the 4,000 range, no more though.

My question is, is this causing more wear on the transmission than it should be, or is it safe to continue doing this without worry?

Also I have read the manual and I never shift into 2 above 70 or below 40. I've used the 1st gear (L) before but only in the city I live in when the hills get too steep. I don't plan to use 1st that often.

Dragonmaster · 02-12-2007, 06:50 PM

Would definitely not recommend doing this in an auto, i've seen many automatic tranmissions blow up due to this. At the point i've seen most of them it is cheaper to get a "new" reman unit than to try and replace the internals of the exisitng as the amount of metal shards strewn throughout make it impossible to get them all out and provide a working transmission afterward.

fistofmeat · 02-12-2007, 06:51 PM

2nd gear is adding torque, so it shouldn't wear your transmition, but it will use up more gas if you do it often. why don't you just get a mt if you don't like to brake to slow down...

diver9000 · 02-12-2007, 08:16 PM

You may not feel comfortable using the brakes, but it would probably benefit you if you learned to like them. However transmissions cost more than a set of brakes but, thats up to you. An automatic is capable of being shifted manually, but it is designed to be automatic....hence the name. Too much will can damage it.

Frankenstipe · 02-12-2007, 08:16 PM

Ok so it does use up more gas and it's bad for the transmission.

Then do I dare even ask why the hell they have the 2 and L gears if it fucks shit up?

And I do want a manual fistomeat but I don't have the money right now and seeing as how my dad bought me the car I don't think he'd be happy if I told him I wanted to trade it in for a manual. Plus I'm just going to wait until I have enough money to buy a cheap little hachi roku and fix it up myself. No point in having a manual if you can't doing anything fun with it like you can in a RWD.

diver9000 · 02-12-2007, 08:29 PM

what can you do in a rwd that is so much more fun? If you use it constantly in 2nd or L its not good for it. Thats why its called an automatic.....2nd is used as an engine brake amon g other reasons like when you are coming down a mountain and you need to a little extra to slow down, and yeah 1st is used for extreme hills or if you are pulling more weight than normal.

Bitter · 02-12-2007, 09:33 PM

it wont use more gas, during a closed throttle downshift the PCM commands the injectors to OFF since no fuel is needed by the engine since the load is less than zero.

and no, its not bad for the transmission.
1. the transmission is constantly up and downshifting
2. as long as you dont bounce off the rev limiter you're fine.
3. keeping the brake system cool on a long downgrade is a good idea

Voodoo.Priest · 02-13-2007, 01:22 AM

I used to have a friend that used to think down shifting in an auto was cool and a good idea until he got the repair bill from his parents to fix the tranny ($1,600). It is not a wise choice unless you want a new transmission.

Frankenstipe · 02-13-2007, 01:43 AM

Quote:

Originally Posted by Bitter

it wont use more gas, during a closed throttle downshift the PCM commands the injectors to OFF since no fuel is needed by the engine since the load is less than zero.

and no, its not bad for the transmission.
1. the transmission is constantly up and downshifting
2. as long as you dont bounce off the rev limiter you're fine.
3. keeping the brake system cool on a long downgrade is a good idea

See now this is a conflict with what everyone else here is saying. Granted you are the first person who sounds like you know what you're talking about, but nonetheless it conflicts. Who am I supposed to believe here eh?

Also I'm not driving around in 2 or L all the time or ever for that matter. If I need to slow down because I don't feel like riding the breaks on long hills or I'm going to fast for a corner I let off the gas, turn off overdrive and downshift to either 2 or L depending on my speed.

Hehe another also, before I really knew how to use the 2 and L "properly", I just downshifted to either of them without knowing the parameters for doing so. So I probably screwed up the transmission a little already, might this have a noticeable affect on my future driving techniques?

***falnfenix*** · 02-13-2007, 06:06 AM

Quote:

Originally Posted by diver9000

what can you do in a rwd that is so much more fun?

have you ever driven a vehicle that isn't FWD?

ghost_ryder35 · 02-13-2007, 08:35 AM

well if your going to be downshifting you automatic, i would change the tranny fluid every other oil change.

tigrpal · 02-13-2007, 09:18 AM

Quote:

Originally Posted by Bitter

it wont use more gas, during a closed throttle downshift the PCM commands the injectors to OFF since no fuel is needed by the engine since the load is less than zero.

and no, its not bad for the transmission.
1. the transmission is constantly up and downshifting
2. as long as you dont bounce off the rev limiter you're fine.
3. keeping the brake system cool on a long downgrade is a good idea

Agreed. I would add:
4. It is sometimes good to be in a lower gear going up the mountain also to keep the transmission cooler. If the auto is constantly shifting trying to find the right gear, it is best to downshift.

Frankenstipe · 02-13-2007, 01:21 PM

Quote:

Originally Posted by ghost_ryder35

well if your going to be downshifting you automatic, i would change the tranny fluid every other oil change.

Thanks for the advice, I'll remember that.

I only have 5600ish miles on it but I wouldn't have anywhere near that if I hadn't taken all those long trips. I had the oil changed once at Jiffy Lube just under 3k miles, I'm not sure what kind of oil they used, it didn't say on the invoice. But I plan to change it again at 8k miles with Mobil 1 Synthetic, would it be a good idea to change the transmission fluid then too?

FYI, I don't usually drive more than 60 on the highway/freeway for gas saving purposes. It tends to be more boring than driving 70 or 80 which is what I was doing before, but I don't really care.

Bitter · 02-13-2007, 03:43 PM

Quote:

Originally Posted by ghost_ryder35

well if your going to be downshifting you automatic, i would change the tranny fluid every other oil change.

thats really excessive, every 30k is enough. trans fluid doesnt get dirty like oil does. just run a good synthetic like redline and you'll be fine.

Dragonmaster · 02-13-2007, 07:17 PM

Have at 'er and keep down shifting that bad boy.

Brake pads $50
trans rebuild $1600-3000 depending on aount of damage (usually on the high end with these cars)

I agree downshifting for a long hill is wise, however downshifting for corners that require a slight scrubbing of speed is down right abusive on an auto transmission.