Automatic Transmission - Shifting back & forth to neutral is safe?

[m6soto]

Hi all!

I'm fairly new here (I should probably post an intro). I drive an '07 Toyota Matrix, automatic transmission. I've been trying out a lot of the different techniques here. The biggest thing that I'm trying new since I've started reading in this forum is using "Neutral" to coast down hills, and to extend my coasts.

Here's my questions:

1. Is it safe to shift back & forth from drive to neutral & vice versa many times while driving?
2. Do I need to try to "rev-match" as I've seen mentioned on the forums here?

Re: Question 1 - Well, manuals are made to be shifted by the driver all the time, but I know that the engineers didn't create automatics w/ the same intent in mind (to be shifted all the time). Do I need to worry about long-term damage over a lifetime of doing this?

Re: Question 2 - I've seen it mentioned on these forums that it's important to rev match when shifting back into drive. And from what I've tried, that's a bad idea in my car. When I shift from neutral to drive, the car seamlessly & smoothly re-engages the gear. When I try to rev-match, though, the car kind of shudders, and sounds like it doesn't like it.

Thanks in advanced for your help!

[desdemona]

Originally Posted by m6soto

Hi all!

I'm fairly new here (I should probably post an intro). I drive an '07 Toyota Matrix, automatic transmission. I've been trying out a lot of the different techniques here. The biggest thing that I'm trying new since I've started reading in this forum is using "Neutral" to coast down hills, and to extend my coasts.

Here's my questions:

1. Is it safe to shift back & forth from drive to neutral & vice versa many times while driving?
2. Do I need to try to "rev-match" as I've seen mentioned on the forums here?

Re: Question 1 - Well, manuals are made to be shifted by the driver all the time, but I know that the engineers didn't create automatics w/ the same intent in mind (to be shifted all the time). Do I need to worry about long-term damage over a lifetime of doing this?

Re: Question 2 - I've seen it mentioned on these forums that it's important to rev match when shifting back into drive. And from what I've tried, that's a bad idea in my car. When I shift from neutral to drive, the car seamlessly & smoothly re-engages the gear. When I try to rev-match, though, the car kind of shudders, and sounds like it doesn't like it.

Thanks in advanced for your help!

Hi,

I do NICE-on with my Toyota Corolla '96. It should be safe to do this. Of course I have 100,00 miles on mine. But I haven't heard any complaining on the transmissions part.
I don't really do it unless I get something out of it. For instance, if the coasting is an actual gain. The big advantage is in how far you are able to coast in neutral vs drive.

I think you might be trying to accelerate too hard. You just barely touch the accelerator. There should be no shudder at all, but it might take a little practice to do this properly. If you have always been a light foot like me, maybe not, but if you are a reformed lead foot then it might take more practice. Just easy does it.

--des

[93Hatch]

Originally Posted by m6soto

Re: Question 2 - I've seen it mentioned on these forums that it's important to rev match when shifting back into drive. And from what I've tried, that's a bad idea in my car. When I shift from neutral to drive, the car seamlessly & smoothly re-engages the gear. When I try to rev-match, though, the car kind of shudders, and sounds like it doesn't like it.

When I shiuft from N to D in my 2000 Accord (without rev-matching) it feels seamless, but at highway speed in the 93 Civic it feels like you dropped the clutch (if it had one) in first gear! I've decided to not shift into N on the highway with the Civic.

Wish me luck, I'm off to see how I did for the week on my first tank with the Civic!

[jimepting]

I think different cars have different transmission setups. Some cars have freewheeling overdrive, so those cars will probably have a "seamless" shift from neutral to drive. (My Toyota Echo, along with the Yaris, seems to be set up this way.) Other cars may have no overdrive gear and no freewheeling arrangement and would therefore require some RPM coordination to allow a smooth shift. The SGII displays RPM, so it should be pretty easy to learn to coordinate engine/road speed.

I have a definitions question myself about NICE-On. Does it mean that I simply bump the transmission in/out of neutral, OR does it mean that I simply leave the gear selector in drive and allow the car to coast. Both techniques display very high, but different, MPG numbers on the SGII.

[theLimeyBrit]

The N in NICE-On stands for Neutral, so NICE-On coasting involves bumping back and forth between drive and neutral.

Just make sure you don't accidentally bump into reverse instead of drive

[desdemona]

Originally Posted by jimepting

I think different cars have different transmission setups. Some cars have freewheeling overdrive, so those cars will probably have a "seamless" shift from neutral to drive. (My Toyota Echo, along with the Yaris, seems to be set up this way.) Other cars may have no overdrive gear and no freewheeling arrangement and would therefore require some RPM coordination to allow a smooth shift. The SGII displays RPM, so it should be pretty easy to learn to coordinate engine/road speed.

I have a definitions question myself about NICE-On. Does it mean that I simply bump the transmission in/out of neutral, OR does it mean that I simply leave the gear selector in drive and allow the car to coast. Both techniques display very high, but different, MPG numbers on the SGII.

You can leave the car in drive and simply take your foot off the accelerator. I do do that sometimes. You won't get the nos. you do for NICE-on but only because you can't get the distance. Sometimes you don't need distance. If I am comign to a hill I do that and at other times.

I wouldn't describe it as bumping in and out of neutral because it implies that you should feel some kind of big change, like a bump. If you do, you are not doing it right. I am guessing that that is more of a figure of speech, but it should be gentle. Easy does it.
If you feel anything too much you are just giving it too much gas that's all there is to it.

--des

[93Hatch]

Originally Posted by desdemona

I think you might be trying to accelerate too hard. You just barely touch the accelerator. There should be no shudder at all, but it might take a little practice to do this properly. If you have always been a light foot like me, maybe not, but if you are a reformed lead foot then it might take more practice. Just easy does it.

I think this is the case. It really takes a light touch to move the rpms from 700 to 1300 or so. I found that in my Civic its an almost imperceptible change when I am doing it right.

[jimepting]

The "bumping" which is perhaps a bad term, was my description of moving the shift lever between neutral and drive. On the Echo, there is no interlock between the two, so it is just a gentel "bump" of the hand. As I said, the Echo seems seamless. Nothing sudden happens and there is no real reaction of the drive train when the neutral-to-drive shift is made. Very smooth.

I wish we could get some comments from someone who has actually studied automatic transmissions internally. I have rebuilt manual transmissions and know a fair amount about them, but not so much on automatics.

[Bruce]

Originally Posted by jimepting

Some cars have freewheeling overdrive, so those cars will probably have a "seamless" shift from neutral to drive. (My Toyota Echo, along with the Yaris, seems to be set up this way.)

You may have mistaken an unlocked torque converter for a freewheeling action, but it's easy to see why this is the case. Many Toyotas (mine included; it's a Yota clone) unlock the TCC when no throttle is applied so the car won't stall if you suddenly slam on the brakes. Since the wheels are driving the engine through an unlocked converter, the engine speed is less than it would be when the converter is locked. Applying just a little throttle pressure in this condition at highway speeds brings the engine speed up naturally and locks the converter.

So, in my car, rev-matching after a Nice-on is automatic as long as the speeds are slow enough and the throttle is applied gently enough.

You can verify that it's not freewheeling by bringing it up to 80 MPH or so and taking your foot off the gas. A freewheeling mechanism would allow idle speed from the engine, whereas an unlocked torque converter should maintain a significant difference above idle speed.

Originally Posted by theLimeyBrit

Just make sure you don't accidentally bump into reverse instead of drive

Don't push the shift interlock button when shifting between neutral and drive; just push the shifter.

As an aside, I've installed a switch and some electronics to manually lock up the TCC for warm-ups, hills and pulse accelerations...but it requires rather careful use.

[olereb1]

I accidentally shifted my 05 Corolla into reverse at 45 mph. Nothing happened, it seems like nuetral. However, at idle it will shift into reverse.