Cruising in Neutral: Bad?

[Shadetree MKNX]

sir Shadetree MKNX,

i drive both a/t and m/t...i i agree with anyone else that you dont need to shift to "n" in a matic or press the the clutch before you brake....

sir otep and sir mazdamazda answered it..and heres my layman's explanation:

on a a/t:you dont need to put to "n", because..once you release the gas pedal on your speeding vehicle,the engine will lower engine speed, so it will no make the vehicle move faster than the point where you release the gas..test it on a open road and see your a/t vehicle will gradually decelerate to 5-10kph with out stepping on the pedal on a long open straight road...for example, an airstrip..applaying your brakes will hasten this effect, and your engine will not die even if you stop to a halt at "D".

on a m/t:try to release your gas pedal, and feel the engine labor...this is what you call engine braking....why you should step first on the brake?simple, the engine itself, when at gear, when you release the gas,your engine labors so in effect your m/t vehicle will slow down until the engine stops...then eventually, the vehicle itself stops. it is recommended that you should apply brakes first until such time when you feel your vehicle is stalling/needs to change gear, then thats the time you press the clutch..

im no racer...i have no such experience or knowledge in racing...im just a person whose life is in everyday driving..and learned everything right based on my experiences.so take my advice..

stop that bad habit of yours...you'll never know when is the time you'll regret that you hit an innocent child because of your bad habit.

Sir,

First of all I would like to acknowledge the nobility and sincerity of your advice. Thank you for your genuine concern.

However, your above post has made it obvious to me how you have grossly misunderstood me all along.

Allow me to clarify once again the main point of my discussion:

I do not believe, nor am I conveying the idea, that it is NECESSARY to
(a)shift an a/t into neutral, or
(b)step on the clutch of an m/t, when making a stop.

What I'm trying to convey here has something to do with EMERGENCY BRAKING.... not "conventional stopping".

As I've said before, I have both theorized and proven to myself (though not by quantitative means), that:

(a)shifting an a/t into neutral, or
(b)applying the clutch on an m/t,

will result in a shorter stopping distance in the event of emergency braking/stopping.

Since you seem to believe that I somehow do not understand what "engine braking" means, I assure you I do. Now, my question to you is this: Do you know what MMI and dashpot are? I ask you not because I want to showcase what little "scrounged up" bits of knowledge I have, but rather to make a point.

Once again, I thank you for your genuine concern, and I hope I've made my point a bit clearer this time.

[Shadetree MKNX]

btw... emergency braking isn't just about stopping in the shortest distance...

it is having control of your car while braking hard & trying to manuever it out of harm's way.

btw, what's faster:

stomping on the brakes then turning the wheels (to avoid the said object)?

or

stomp on the brakes, let one hand leave the steering wheel (which will be useless when your wheels lockup) then pop the shifter into neutral?

If the driver has decided in a split second, to swerve around an obstacle, which do you think is going to happen first, him yanking the steering or him stepping on the brakes?

Of course, he's going to yank on the steering first. Why? Because his hands are already on the steering wheel, while his right foot is still coming out of the gas.

Because steering is more of in immediate access to the driver the timing of the application of the brakes, clutch, and shifter, become irrelevant until afterwards.

Besides, it is also a generally good idea to stop rather than just to swerve blindly. Unless yours is the only vehicle on the road, you run a good risk of hitting cars beside or behind you, or worse, the oncoming traffic, if you make it a habit to swerve around an obstacle.

In fact, it might even be more dangerous to develop the habit of swerving, than to practice the habit of hitting the clutch, or shifting an a/t into neutral.

(BTW, it's gotten more and more difficult for me to post with my slow dial-up connxn. I found out I had to log on everytime I need to make a post, hence my slow response.)

[mazdamazda]

Besides, it is also a generally good idea to stop rather than just to swerve blindly. Unless yours is the only vehicle on the road, you run a good risk of hitting cars beside or behind you, or worse, the oncoming traffic, if you make it a habit to swerve around an obstacle.

It isn't a choice between stopping & swerving... why pick only one when you can do both? That is why the ABS is becoming a standard among cars nowadays...

Believe me... the ABS has already saved me a couple of times (coupled with the brake then steer technique)!

The most memorable is in our parking lot in the office which was newly painted & wet (from the rain). A very lethal mix when I turned a bit fast on a corner... the brakes were practically useless but I was still able to steer safely out of the obstacle (with just inches to spare).

[Shadetree MKNX]

It isn't a choice between stopping & swerving... why pick only one when you can do both? That is why the ABS is becoming a standard among cars nowadays...

Believe me... the ABS has already saved me a couple of times (coupled with the brake then steer technique)!

The most memorable is in our parking lot in the office which was newly painted & wet (from the rain). A very lethal mix when I turned a bit fast on a corner... the brakes were practically useless but I was still able to steer safely out of the obstacle (with just inches to spare).

For parking lot maneuvers, it would definitely be frivolous to "slap the a/t into neutral" everytime you need to stop.

I was thinking more of regular highway traffic and speeds where the unexpected can happen real fast, and there is very little time to think and react.

My idea of getting into the habit of slapping the a/t into neutral reduces the amount of things I have to check and consider before I react to any given traffic emergency. Diving to the right or left is kind of like a 3rd, even 4th option for me because I am usually in a relaxed state, and not in a state of heightened awareness, to be constantly aware of what's going on behind and beside me.

I have to admit, leaving both hands on the steering wheel should afford you the advantage of being able to steer better than with only the left hand on the wheel. However, I would also have to assert the fact that stopping in a straight line will definitely be much quicker with the a/t shifted into neutral. Perhaps, this is what Mercedes had in mind when they decided to develop their "brake assist" technology.

Given the way this discussion has turned out, I must agree with Mazdamazda that braking and steering is best carried out with both hands on the wheel. Just make sure you know where you're steering into.

[mazdamazda]

For parking lot maneuvers, it would definitely be frivolous to "slap the a/t into neutral" everytime you need to stop.

Am travelling at a fast pace going to towards the exit... not really a parking lot manuever. Hehe. Really caught me off guard!!!

However, I would also have to assert the fact that stopping in a straight line will definitely be much quicker with the a/t shifted into neutral. Perhaps, this is what Mercedes had in mind when they decided to develop their "brake assist" technology.

MB's Brake Assist works differently. It will try to "learn" the braking habits of a driver. Then assess whether or not you are braking normally or if it is an emergency case. If it detects that it is the latter, it will electronically "assist" you in applying full braking power (since most of us don't have enough reflxes to apply full braking power). Read more about it here: http://www.canadiandriver.com/articles/jk/at_010501.htm

Will though experiment which braking technique would be better (either clutch w/ brake or brake first, clutch later) for a manual tranny.

[pixelparadigm]

I tried slowing down from 40kph to 10kph really fast when I double clutched then pop the stick to 1st gear without stepping on the brakes that much. From time to time, I practice heel and toe when the road is clear.

[Shadetree MKNX]

Am travelling at a fast pace going to towards the exit... not really a parking lot manuever. Hehe. Really caught me off guard!!!



MB's Brake Assist works differently. It will try to "learn" the braking habits of a driver. Then assess whether or not you are braking normally or if it is an emergency case. If it detects that it is the latter, it will electronically "assist" you in applying full braking power (since most of us don't have enough reflxes to apply full braking power). Read more about it here: http://www.canadiandriver.com/articles/jk/at_010501.htm

Will though experiment which braking technique would be better (either clutch w/ brake or brake first, clutch later) for a manual tranny.

I already know about M-B's Brake Assist. What I meant was I think their engineers figured out how the engine adds more work for the brakes during emergency braking, hence the need to further boost the already boosted hydraulic system during such event. I suppose they could further refine the system by causing the electronically-controlled A/T to disengage the forward clutch when Brake-Assist is being activated. The clutch would then be re-engaged the moment the system returns to normal mode.

[likot]

Am travelling at a fast pace going to towards the exit... not really a parking lot manuever. Hehe. Really caught me off guard!!!



MB's Brake Assist works differently. It will try to "learn" the braking habits of a driver. Then assess whether or not you are braking normally or if it is an emergency case. If it detects that it is the latter, it will electronically "assist" you in applying full braking power (since most of us don't have enough reflxes to apply full braking power). Read more about it here: http://www.canadiandriver.com/articles/jk/at_010501.htm

Will though experiment which braking technique would be better (either clutch w/ brake or brake first, clutch later) for a manual tranny.

pano kung walang break assist ang asa likod mo at nag super break ka sapul ang likod mo dapat naka break assist lahat kotse kung implement nila yan!!!

[mazdamazda]

What I meant was I think their engineers figured out how the engine adds more work for the brakes during emergency braking, hence the need to further boost the already boosted hydraulic system during such event.

What they are trying to improve is the driver reaction time & application of full brakes during an emergency...

I suppose they could further refine the system by causing the electronically-controlled A/T to disengage the forward clutch when Brake-Assist is being activated. The clutch would then be re-engaged the moment the system returns to normal mode.

You'll lose much of your steering capability if that happens. As what I've said... braking + steering is the best way to avoid an obstacle.

If you really want to apply full braking power... then just pull up your emergency brakes. It is that simple.

[niky]

actually, the e-brake won't make you stop any faster if you're already on the brakes, as all the weight of your car is shifted to the front.

It will help you swap ends (spin sideways) quite easily though... although whether that's a good thing or not is debatable. :D

[Shadetree MKNX]

What they are trying to improve is the driver reaction time & application of full brakes during an emergency....

It's the same thing.

You'll lose much of your steering capability if that happens.

That's just flat out wrong. Disengaging the clutch (whether in an a/t or an m/t) does not cause one to lose steering capability, period.

As what I've said... braking + steering is the best way to avoid an obstacle...

Not necessarily true. In some cases maybe, but not always. Just like I've been trying to point out before, the option to steer also depends on the traffic situation.

That's the whole point behind my "theory"--you have to look before you steer. In high volume, high speed traffic situations, there's just not enough time to check your mirrors before diving into an "open" lane to avoid a potential frontal collision.

If you carefully check my post, I merely agreed that a driver can steer better with both hands on the steering wheel. But I didn't say that the best way to avoid a frontal collision is to steer and brake.

One thing we have to understand here is that during an emergency the "braking" part is imperative, while the "steering" part is conditional.

If you really want to apply full braking power... then just pull up your emergency brakes. It is that simple.

Like Niky said, you risk spinning the vehicle by "over-braking" the rearend. That's the main reason why they put proportioning valves in the brake's hydraulic system. Also, that's why a manufacturer always gives more priority on the rear when installing a "1-axle-only" ABS system. In other words, you can never hear of a car with front ABS only. Rear-only and 4-wheel ABS, yes--but not front only.

[number001]

Some Quotes from the Mazda 3 owner's manual (US version), which is related to the topic. Refer to page 5-10, 5-11. Dont know if these ideas were presented by any previous posters.

Warning:
>Shifting into N while Driving: Shifting into N while driving is dangerous. Engine braking cannot be applied when decelerating which could lead to an accident or serious injury. Do not shift into N when driving the vehicle.

Caution
>Do not shift into N when driving the vehicle. Doing so can cause transaxle damage.

>Shifting into P, N or R while the vehicle is moving can damage your transaxle.

[manilenio]

After reading through the discussion, I was left with the impression that this is a very serious discussion being engaged in by shadetree and mazdamazda, who both know their stuff. I don't know any technical talk about the engine, ABS, and brakes so I'll just contribute my crazy idea... If you learned to drive with a manual tranny, the reason why in an emergency you step on both the clutch and the brake is to prevent the engine from dying. I really don't know if it makes the vehicle stop sooner or not, but I guess it has something to do with having both feet pushing, so you have more force stepping on the brake . I don't really know if stepping on the brakes AND shifting to N in an a/t vehicle will make it stop sooner, because what would it achieve by releasing the gear at the point of braking unless shifting to N engages some kind of a gear that aids stopping power? Besides, isn't it bad for an a/t to shift to N while the vehicle is moving, regardless if all the wheels are being braked? Again, I'm not trying to make a point, just contributing to the discussion hehe

[afrasay]

I wouldn't compromise gasoline consumption and parts wear to safety.

[theveed]

Ever heard of overheating brake fluid?

Funny how most sites DO NOT recommend shifting to N when coasting especially downhill...

http://www.popularmechanics.com/auto...o/4230705.html

Q: I have a question about fuel economy. If you are driving downhill, do you save gas by putting your transmission in Neutral and coasting, instead of having your vehicle in Drive? I think that you do but my wife seems to disagree. Can you give me the correct answer, so I can tell her that I’m “Mr. Right,” as usual?

A: That depends. The engine isn’t braking the car going downhill if the transmission is in Neutral, so economy would seem to be high. But if you think the engine is still using fuel while coasting downhill in gear, you’re laboring under a misconception. Most fuel-injected cars turn the fuel delivery completely off when you lift your foot from the accelerator. They still burn fuel when idling in Neutral, so do the math. The amount of fuel burned at idle over, say, a couple of miles of coasting downhill is small, but it’s still more than zero. So if you’re driving a modern fuel-injected car, you’re wrong.

Older, carbureted cars would suck gas through the engine while coasting in gear, even if you turned off the ignition switch. In this case you’d be right.

http://www.automaticdrivingni.com/drivinganauto.html

2. This position is a held gear and could be used when negotiating a long, steep downhill gradient, this helps keep the speed down without too much overuse ( and overheating) of the brakes. It may also be used in a properly planned overtaking manoeuvre where a lower ratio is required for more acceleration.

1 or L. Another lower held gear This will prevent the gear changing up automatically, which may result in the vehicle ‘running on’ and increasing speed when this is not required, for example in severe weather conditions where snow or ice and mud etc would cause wheel spin.

http://thefuntimesguide.com/2005/07/downhilldriving.php

On The Downhill

Instead of using your brakes to slow your vehicle down on a steep grade, use what is known as "engine braking" (big-rig drivers use something similar called "jake brake").

This is a good idea if you want to:
a) save your brakes a lot of unnecessary wear & tear
b) actually HAVE brakes at the end of the hill!
In fact, you will increase the life of your brakes by a few months (or even years, depending on how much steep downhill driving you do) if you simply use engine braking whenever possible, rather than actually pressing the brake pedal to slow your vehicle.


In short, you are literally using the engine to break the speed of your vehicle traveling downhill.

http://www.telegraph.co.uk/motoring/...2/emrask30.xml

Both your observer and police driver are correct in the statement that engine braking is old hat, but one must be flexible and able to use older skills when necessary.


An example of this is when driving down very steep hills in a car with an automatic gearbox. In these circumstances, the automatic will change up and provide little control. Holding down a gear (or two) on the automatic will maintain a degree of engine braking, prevent excessive heat build-up in the brakes and maintain safety and control. End of argument.

http://theautoprophet.blogspot.com/2...e-braking.html

In my experience, there is less braking effort required if you use technique #1 above, and I suspect less brake wear. If you rely only on "foot" braking when driving downhill, you will boil your fluid, and have little braking power at all.

http://www.middledural.com/html/driver_rules.html

Brake failure often occurs going down hills as a result of poor driving. Dependence on the brakes to slow a vehicle travelling downhill causes overheating which in turn leads to brake fade, or brake burn-out in which the brake linings completely lose their grip and are no longer effective. Brake failure can be prevented by good driving techniques.


When going down hills:


Select a gear low enough to slow down the vehicle without the constant use of brakes. If you try to gear down but you miss the gear, stop the vehicle with the brakes immediately, then select the correct gear. Attempting to coast while you struggle with the gears is very dangerous.

Personally, I've experienced brake fluid boiling when a long line of cars were going to Highlands a few years back (downhill), the brakes were sliding due to the excessive use of drag-braking while going downhill.

[manilenio]

How do you engine brake with an a/t by the way?

[theveed]

Just move the gear lever to 2 or 1

[mbeige]

^ Just make sure your next lower gear will not force the engine to go beyond it's recommended speed. If the tachometer is already near redline try to avoid shifting down unless you know and can correctly predict what engine speed (RPM) the tach will read once you downshift, and it will not over rev the engine.

[niky]

brake fluid boil? I've done that on flat roads... ...drive any normal road car hard enough and eventually the brakes will not be able to stop it.

The cure? drive smarter. Or, in my case, get braided lines, DOT4 fluid, and better brakes...

[manilenio]

Just move the gear lever to 2 or 1

Sir, my old car only has D4, D3, and 2... So if I'm using D4, I shift to D3 or 2?