Cruising in Neutral: Bad?

[pajerokid]

it won't break your car.... provided you make sure that revs are appropriately matched when you re-engage the gearbox, whether for manuals or automatics.

i think the reason why it is not advisable to cruise in neutral is that you lose precious time in case of an emergency where you may need power instantly.

Exactly.

[OTEP]

Shadetree,

I'm not saying that braking and accelerating is a maneuver regularly done. But it does happen (e.g. stuck throttle). Remember that the early DMC's had to have throttle cable protector installed because the cable tended to remain stuck in the 'open' position.

All I'm saying is that the brakes are capable of reigning in the engine power.

Comparing to a manual is not really that fair since a disengaged clutch has no slippage whereas a slushbox in braking will already have its torque converter unlocked and there will be enough slippage in the system already. Sure, neutral has the potential to shave a foot or two, but I don't think its worth the risk.

[mazdamazda]

And if that's not enough, just ask anybody who's good with a stick-shift and ask them what they do in a situation where they need to stop at the quickest possible time, and they will most invariably tell you that they'll stomp on the clutch and the brakes at the same time.

That is a myth that is being tackled when you enroll in a racing / circuit driving course.

Brake before applying the clutch. The stopping power of your brakes will be maximized and reduces 100-0kph braking distance by around 10 feet.

On the matter of applying max braking, then max acceleration the next second, I don't think there's such a real-world situation, nor do I believe in the possibility of the success of such a maneuver. It's either you brake, brake and swerve, or accelerate; never brake and accelerate in such a short amount of time. If you come to think of it, braking and accelerating are both mutually exclusive and would only cancel each other's effects when combined together.

When you understeer or oversteer you might even need the accelerator to correct your vehicle.

Btw, if you neutral cruise when you are doing your driver's license test in the USA, you'll probably flunk it. That is a big no-no over there.

are you sure mr ramirez cruised at nuetral? as i understand there is a "trick" you can do with the the jazz that will make you save fuel. corect me if i'm wrong but at a certain speed range the jazz's engine wouldn't be using all cylinders and that is where you save fuel.

OT

The Jazz doesn't have that function (Multi Displacement System). That is only being employed by some high-displacement engines (e.g. 300C Hemi).

[RafRaf]

thanks for correcting me mazda-mazda. anyway, i saw an article saying the jazz used by mr ramirez was a 1.3 MT. here is the link...

http://www.tribune.net.ph/motoring/20050607.mot06.html

maybe he did cruise... it says they stayed mostly at 40-60kph and did 80kph on downhills.

[Shadetree MKNX]

That is a myth that is being tackled when you enroll in a racing / circuit driving course.

Brake before applying the clutch. The stopping power of your brakes will be maximized and reduces 100-0kph braking distance by around 10 feet.

Anybody who knows what "dashpot" is all about ought to understand why shifting an a/t into neutral or punching the clutch in in a manual, should provide the shortest stops.

Competition driving is not exactly the same as everyday driving. Engine braking into a turn provides better modulation of the brakes and also allows smoother power transitions when exiting the turn.

BTW, is there a link to some website that shows how using engine braking can shorten the stopping distance by 10 feet? I'm just curious about how it was done, what the conditions were, and what cars were being used.

When you understeer or oversteer you might even need the accelerator to correct your vehicle.

Btw, if you neutral cruise when you are doing your driver's license test in the USA, you'll probably flunk it. That is a big no-no over there.

Again, we're not talking about race car driving techniques. Let's just limit the discussion to emergency braking.

Also, I wasn't arguing about the benefits of "cruising in neutral". If you kindly read some of my previous posts, you will see how I even cited a blunder commited by somebody who didn't think much about the dangers of rolling a truck in neutral.

All I'm saying is that I find it a good idea to develop the habit of "slapping" the a/t into neutral, or stomping on the clutch in a "manual", when I need to make an emergency stop.

Personally, I think, or rather, I believe, the reason why authorities discourage "cruising in neutral" is because new drivers don't know any better about how to drive properly in the first place. I believe that any person with a good understanding of the dynamics of motor vehicles should be able to ascertain what's safe and what's not, given careful thought. There are indeed so-called "finer points" in the art of operating a vehicle that only an enthusiast would care to explore. Nevertheless, *general guidlines* are there for the "general motoring public".

[Karding]

It's actually easy to know - your brake lights will be on the entire length of the downgrade.

Really? Because I used to coast downhill without stepping on the brakes until I reach the bottom of the hill. In addition, you can still be on gear and still have your foot lightly on the brake to help you slow down. Dont you see those cars with their brakelights ON and OFF during downhill? Or do you assume that they are 'coasting' in neutral?

[jarx]

I think another reason NOT to shift to Neutral (or not to step on the clutch), is that the engine would help prevent you from locking up. Of course it wouldn't matter if you have ABS. Leaving the car in a low gear during emergency braking would also be better becuase of engine braking.

For A/T, I tried shifting to N during braking and I felt the brakes bite harder, but it's only from 20kph, so I'm not sure if it will be the same for emergency braking.

[alwayz_yummy]

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.

[Shadetree MKNX]

I think another reason NOT to shift to Neutral (or not to step on the clutch), is that the engine would help prevent you from locking up.

Actually, the rest of the drivetrain is still going to be "fighting" against the brakes, even when the engine is being disconnected from the wheels. There is still a lot of "rotational mass" that's running at high speed when the clutch is applied (or a/t shifted to "N"), and all that energy is still going to have to be absorbed by the brakes and suspension.

Granted the engine may help prevent or postpone wheel lockup, but a car skidding to a stop still stands a better chance in stopping than one that's being pushed on by the engine.

Of course it wouldn't matter if you have ABS. Leaving the car in a low gear during emergency braking would also be better becuase of engine braking.

Emergency braking entails decision and reaction times in the split second range. Having the "presence of mind" to down shift for engine braking, not to mention the precision in one's movements required to execute such a complex task, in addition to stomping on the brakes, would really put such a feat into the "superhuman" category.

I must tell you that even the simple task of "slapping" the shifter into neutral takes a lot of getting used to before it becomes part of you. Like I pointed out in my previous posts, I make a habit of doing it even on non-emergency stops just to keep me attuned to it to the point that the act becomes fully automatic when the real emergency comes.

For A/T, I tried shifting to N during braking and I felt the brakes bite harder, but it's only from 20kph, so I'm not sure if it will be the same for emergency braking.

That's exactly what I'm talking about. I know you don't have much of a reason to agree with me, much less believe in the things I say, but it really works great for me. Just try and make a habit of it whenever you stop the car, and you'll soon find out how much quicker your reaction time will be when the need arises.

[mazdamazda]

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?