Shifting (A/T)

[daq421]

I've found that the little Yaris responds very well to "shifting" during back road runs. Using the auto trans more like a stick, working up and down the gears as I accelerate and decelerate, both into and out of turns. It responds so well I find myself wondering if it's designed to be run that way..

Any thoughts?
-Peter

[Spades]

I haven't had experience with the automatic transmission used in the Yaris, but if it is like most auto trans I have had experience with, constantly shifting your auto trans like it is a manual generally leads to transmission failure sooner than leaving it in gear would.

I have been told not to do this by many people MUCH smarter than myself, and I have listened to their advice and have seen a couple cases where transmissions went bad at 30k miles from people using them like a manual gearbox.

To sum it all up, if you wanted a manual you shouldn't have bought a auto. The automatic transmission in your car was designed to shift at the right time to increase longevity of both the engine and transmission. From the performance side of it, I have yet to see a auto car run quicker times when shifted manual instead of leaving it in drive...its usually 1 second slower in the quarter mile by pretending your slushbox was a gearbox.

[KSIbucky]

Originally Posted by Spades

I haven't had experience with the automatic transmission used in the Yaris, but if it is like most auto trans I have had experience with, constantly shifting your auto trans like it is a manual generally leads to transmission failure sooner than leaving it in gear would.

I have been told not to do this by many people MUCH smarter than myself, and I have listened to their advice and have seen a couple cases where transmissions went bad at 30k miles from people using them like a manual gearbox.

To sum it all up, if you wanted a manual you shouldn't have bought a auto. The automatic transmission in your car was designed to shift at the right time to increase longevity of both the engine and transmission. From the performance side of it, I have yet to see a auto car run quicker times when shifted manual instead of leaving it in drive...its usually 1 second slower in the quarter mile by pretending your slushbox was a gearbox.

I agree not a good idea

[St_G]

I don't see much point in playing fake manual on acceleration, but I also don't see much problem in forcing a downshift for a turn...

[Spades]

St G, I won't tell you how to drive your car. I am just saying I have seen bad things happen when people do this, simply my opinion. Perhaps we have a transmission guru on this site who will state if this is bad to the transmission or not.

I do know that it is a waste of time, as when you are driving an automatic properly through corners, there is no need to manually shift, and you actually get in and out of corners quicker...brake hard just up to the corner, then mash your foot to the floor and use the front wheels to pull the car around the corner...pretty simple.

Trying to shift it manually just slows the process down all in the name of feeling like a speedracer.

[Spades]

I am perhaps wrong on this, but my understanding of auto transmissions leads me to belive the first thing to go out on a auto trans for manually shifting it on the fly would be the Torque Converter or the "Sun Gear". The "sun gear" as it was explained to me, is the main gear behind the torque converter. If the gear looses teeth due to abuse (such as shifting it down gears or by dropping it from drive to reverse without letting the car come to a stop first) the teeth will go through your transmission and rip it apart.

On manual vehicles you have a clutch, this is differant than a torque converter. The clutch has the same job, but works differantly. By downshifting gears on a manual, you SHOULD step on the gas to bring the RPM's up to the speed you are traveling. Failure to do this will result in premature clutch failure. The torque converter is responsible for having to go between the speed you are traveling and the RPM's of the engine. This creates enormous amounts of strain on your torque converter, and unlike a $500 clutch, if the torque converter and sungear go bye-bye, you may loose the automatic transmission with it, and thats more like $2k+.

As I said, I may be talking out of my ass, that is just what I know. Again, play with your auto trans at your own risk kiddies.

[rockchops]

Originally Posted by Spades

I am perhaps wrong on this, but my understanding of auto transmissions leads me to belive the first thing to go out on a auto trans for manually shifting it on the fly would be the Torque Converter or the "Sun Gear". The "sun gear" as it was explained to me, is the main gear behind the torque converter. If the gear looses teeth due to abuse (such as shifting it down gears or by dropping it from drive to reverse without letting the car come to a stop first) the teeth will go through your transmission and rip it apar...

Very sound advice IMO, Spades. I've been told in the past that I have a bad habbit of shifting A/T cars into drive prematurely, after backing out of the driveway. Now it seems that there is some merit to these claims from my folks.

[daq421]

Originally Posted by St_G

I don't see much point in playing fake manual on acceleration, but I also don't see much problem in forcing a downshift for a turn...

It's almost entirely coming into corners, I "downshift" to gain the right rev's to pull through a turn. I'm not shifting up from lights for "dragging" or anything..

Heck, it's just that I noticed the little car seems to handle it well...
-Pter

[daq421]

Originally Posted by Spades

I do know that it is a waste of time, as when you are driving an automatic properly through corners, there is no need to manually shift, and you actually get in and out of corners quicker...brake hard just up to the corner, then mash your foot to the floor and use the front wheels to pull the car around the corner...pretty simple.

Trying to shift it manually just slows the process down all in the name of feeling like a speedracer.

Hmmm, the fly by wire throttle response is not accurate enough for "peddle mashing" into a turnm as you cannot count on power arriving when you need it. Dropping into 3rd (or 2nd from 3rd depending upon your traveling speed) as you enter a turn brings up the RPM's and gives a much more controlled power band.

-Peter

[Spades]

I am not saying it doesn't feel like you are more in control, I am just saying your feelings are lying to you and that it is also actually hard on your transmission, read my above post.

[St_G]

This is somewhat tangential to the meat of the issue here, but has anyone else noticed that car manufacturers sometimes actually present driver's doing exactly this in their commercials? I know I saw it in a Mazda commercial recently, for (iirc) the CR-7.

[daq421]

Originally Posted by Spades

I am not saying it doesn't feel like you are more in control, I am just saying your feelings are lying to you and that it is also actually hard on your transmission, read my above post.

Ok.. I'm sure the act of manually downshifting the car is harder on it, in this we agree but I find the "...I am just saying your feelings are lying to you..." statement very odd, as there is nothing I can say in response that does not sound defensive. So, I'll just say thanks for the input, I appreciate it. I guess I'll be less inclined to downshift into corners, unless I really feel it's required.

Thanks all
-Peter

[St_G]

Related question: Is there something special about the construction of automatic transmissions with sequential-manual options -- the paddle shifters in the Fit, VW's tiptronic, BMW's SMT... -- that protects against the wear/damage you warn of?

It may be worth noting, that in a quick google search, I don't see any (purported) professional articles suggesting much danger in the practice. I'm not claiming that's the final word on the issue. But that's what I'm finding so far.

[Razr]

I have been manually changing auto boxes for 15 years, and have *never* had even an inkling that a problem was developing. From my experience this talk of it damaging your box is a total urban myth. Maybe we should get Mythbusters onto it LOL!

That said, pre-empting a downshift for a hill or turn has a marked improvement in acceleration and vehicle control. Don't let anecdotal reports stating it won't change anything fool you. It fucking works, period.

[Spades]

hrm, ok, I guess I was talking out of my ass...however, just your saying you have done it for 15 years doesn't make me belive in the slightest that it isn't hard on automatic transmissions, at least not untill you have proof contradicting my explanation.

The whole "it has never happened to me so it must not be a problem" argument doesn't make me belive that it isn't hard on automatic transmissions.

I suggest you go talk to some gentamen that work at transmission repair shops and get their opinions on this, and maybe I will find that the people I have talked to and what I have personally experienced are completely wrong or coincedental.

EDIT: and supposing that I am wrong, and that the feeling of control you are experiencing is actually the improvement you speak of, it all goes back to the original question, why did you buy a auto in the first place? If the control is so much better, then why buy a auto to begin with? I still dont belive it helps cornering. I have never seen any professional driver that were cornering for speed manually downshift a auto trans, again, this is just what I have seen.

[Razr]

Originally Posted by Spades

hrm, ok, I guess I was talking out of my ass...however, just your saying you have done it for 15 years doesn't make me belive in the slightest that it isn't hard on automatic transmissions, at least not untill you have proof contradicting my explanation.

The whole "it has never happened to me so it must not be a problem" argument doesn't make me belive that it isn't hard on automatic transmissions.

I suggest you go talk to some gentamen that work at transmission repair shops and get their opinions on this, and maybe I will find that the people I have talked to and what I have personally experienced are completely wrong or coincedental.

EDIT: and supposing that I am wrong, and that the feeling of control you are experiencing is actually the improvement you speak of, it all goes back to the original question, why did you buy a auto in the first place? If the control is so much better, then why buy a auto to begin with? I still dont belive it helps cornering. I have never seen any professional driver that were cornering for speed manually downshift a auto trans, again, this is just what I have seen.

You know, the whole "some guy told me so" argument doesn't wash either unfortunately.

I suggest you take a little of your own advice, and front up with some hard facts to support your position, before you ask that of me. My opinion is worth the same as yours here, and an opinion is all you're providing.

Surely if the practice of manually downshifting an automatic transmission is in fact as detrimental to your gearbox as you suggest, there will be numerous, independant online sources you could quote here, and undoubtedly there'd also be a warning and waranty disclaimer in your vehicle handbook against such practices. Go find them, link/display them here, and I will humbly apologise to the OP and yourself for providing ill-conceived advice.

As for why *I* bought an auto, it's actually very simple: I'm not the only one that drives the car. Think a little further than your own little sphere before making assumptions about others and their decisions.

You've never seen a professional driver downshift for a corner? You're kidding right?

I hope you realize that the practice of downshifting has nothing to do with auto vs. manual gearboxes, it's all about selecting a gear ratio that's best suited to what's about to happen on the road. Are you telling me that if you're approaching a hill, or about to overtake, or anything else that requires additional acceleration that the current gear ratio couldn't provide you with effeciently, that you don't change down gears? Must be interesting driving a stick shift in 5th gear all the time LOL.

The point is that all auto boxes always lag on downshifts, and pre-emptive downshifts can quite literally save you a second or more. One second is a heck of a lot of time at 60mph. It can make a huge difference.

[Razr]

OK, Im reading the owner's manual and am seeing Toyota's recommendations on manual downshifting of the auto transmission.

I've attached it to save you the time of getting it out of your car.

Have a read of pages 112 and 113 (6 and 7 respectively in the PDF). 'Nuff said?

[[FR] Sébastien Loeb]

AUTO TRAN = NO NEED TO MANUALLY SHIFT

MAUNAL TRAN = NEED TO MANUALLY SHIFT

CLEAR ENOUGH?