[phamilyman]

Originally Posted by (Alok)

We are discussing a very basic thing here. It is just like ‘press the clutch while changing the gear’.

If a person does this (Shifting to Neutral or Pressing the Clutch when Braking), he should join motor driving school to learn driving. Just holding the steering and pushing the accelerator is not enough.

My man, I like how you equate one practice (that you clearly do not practice and hence do not fully understand) with having zero skills as a driver.

I mean, are we here to pass judgement on each other (rather impose our preset notions on the world?) or open our minds to what can be done?

Well, my 1 L km of driving in the last 4.5 years do not quite agree with you - and I do this every day, every time that I think it is appropriate. Here is what I said last July, and still stand by: http://www.team-bhp.com/forum/techni...ml#post2541126

Try it before you knock it. I'm sure everyone's developed their systems - use what works for you. But please don't assume that's what is exactly needed. To each their own.

PS: This is not about downhill, but City driving.

[Aroy]

Originally Posted by chetanthaker

When you plan on slowing down or are going downhill, put your car in the highest gear available and let it cruise. You will use zero fuel while doing so. Slow down to about 20kmph, and at a safe distance, press clutch and go to neutral or your desired gear

Source: Top Gear

I also beg to differ.

On a moderate slope in the highest gear (say 5th), you will accelerate even with your foot off the accelerator, as there is minimal engine braking.

On a steep slope you will accelerate at an alarming rate.

That is why the golden rule is to descend in the gear you will be climbing the slope in. That ensures that the engine braking is effective in slowing you if you take your foot off the accelerator.

[AjayJoshuaN]

When riding a bicycle, if you stop pedaling, is it considered to be out of control? Considering yourself to be the engine of a bicycle, imagine if the wheel was connected with the pedal in such a way that the pedal always rotates when the wheel rotates (even if you stop pedaling, since the wheel continues to rotate, the pedal also still continues to rotate, so you'll have to move your legs along with the pedal which will wear out your leg joints!)... unfortunately, for cars this luxury of coasting by just resting your legs is not there... you take your leg of the accelerator and... the annoying braking effect of the engine kicks in

I think driving in neutral (not down hill ) is a good practice, because:
-It keeps the engine at idling RPM, reducing unnecessary friction between the pistons and cylinders, which generates lesser heat
- Reduces the unnecessary braking effect of the engine on the wheels

When I drive, especially on highways, once I reach around 80~85 Km/h, I switch to neutral and coast... after sometime, when the speed reaches around 70~75, switch back to gear and then again reach 80~85Km/h... and repeat the process again... it is inefficient to keep your foot constantly on the accelerator just to maintain a constant speed... more fuel is wasted...

Just like driving a car, one should learn how to make use of coasting in neutral in the right way... it is a skill one should learn... The major area where one should avoid coasting in neutral is to coast down a hill...

Other that that, I think driving in neutral is a good practice... once you learn it and get used to it, you will understand (just like driving a bicycle, it is not considered a bad thing to coast in a bicycle )

[racer_m]

I have the complete opposite view.

IMO it is not a good practice to coast in neutral in any situation. Reasons maybe:
(please note, You is not to the OP but to the general reader)

1. You are not in control of the car. Remember in a braking situation you definitely need the so called "annoying braking effect". In a panic braking situation, the less said about being is neutral the better.

2. You will seriously wear out your clutch/gear/drive train mechanism just to save some imaginary fuel. Seriously you strain a lot of components when you suddenly slot in a gear right from neutral at a high speed.

3. You will wear out your whole body rather than just one leg, by doing the gear shift/clutch/steering circus for the neutral coasting (and that too very frequently)

4. You will be more distracted/exhausted and juggle your concentration between Speedometer/Road Hazards/Correct shifting, etc rather than focus on a relaxed driving and observing the environment around you.

There are very few places in India(very wide expressways/extremely deserted roads) where you can actually use the auto cruise and in turn the so called neutral coasting to even make this a useful and common driving practice

[Samurai]

Originally Posted by AjayJoshuaN

When riding a bicycle, if you stop pedaling, is it considered to be out of control?

Before you equate motor vehicles to a cycle, kindly read this thread fully.

This subject has been discussed numerous times and there is really no new arguments to be made.

[Rehaan]

Originally Posted by AjayJoshuaN

When I drive, especially on highways, once I reach around 80~85 Km/h, I switch to neutral and coast... after sometime, when the speed reaches around 70~75, switch back to gear and then again reach 80~85Km/h... and repeat the process again... it is inefficient to keep your foot constantly on the accelerator just to maintain a constant speed... more fuel is wasted...

Please read this thread. Specifically posts that explain "DFCO" (you can search the thread for it). That might help explain to you why you're wrong.

Originally Posted by AjayJoshuaN

The major area where one should avoid coasting in neutral is to coast down a hill...

At least we agree on something

Originally Posted by AjayJoshuaN

just like driving a bicycle, it is not considered a bad thing to coast in a bicycle

This is a bad comparison because the 'engine' (rider) of the bicycle can only provide power through the pedals, not braking or any type of resistance.

Exception would be fixed gear bicycles ("fixies"), and i don't think I've ever seen a fixie rider take his feet off the pedals to just "coast".

cya
R

[saket77]

Originally Posted by AjayJoshuaN

Other that that, I think driving in neutral is a good practice... once you learn it and get used to it, you will understand (just like driving a bicycle, it is not considered a bad thing to coast in a bicycle )

Ajay, first things first, welcome to TBHP family!

I hate to contradict your first post but for safe & efficient driving, you need to correct your driving technique posted above. Contradictory to what you think, modern cars require minimal fuel to keep them going at a constant speed on a flat road. Also, while coasting in gear, modern ECUs completely (or mostly) cut down the fuel supply to the cylinders and that makes it a very efficient technique to save fuel. Plus that keeps you in control as you have engine braking, plus the power to accelerate immediately, if the need arises to. On the other hand, coasting in neutral will push the engine to go at idle and it will consume fuel at the idling rate; and you lose engine braking and power to accelerate. Not to mention the additional stress you put on the drivetrain & clutch to shift from neutral to a gear at high speeds.

Please also go through this thread and your most doubts would be cleared: http://www.team-bhp.com/forum/techni...save-fuel.html

Drive Safe!

Reagrds,
Saket

[::CMS::]

Originally Posted by AjayJoshuaN

When I drive, especially on highways, once I reach around 80~85 Km/h, I switch to neutral and coast... after sometime, when the speed reaches around 70~75, switch back to gear and then again reach 80~85Km/h... and repeat the process again...

Save the clutch plates than a few drops of fuel

it is inefficient to keep your foot constantly on the accelerator just to maintain a constant speed... more fuel is wasted...

Yes, keeping the accelerator throughout will increase fuel consumption, however coasting in the desired gear based on the rpm \ speed is the best option than neutral. FYI, depending on the ECU map, atleast in my case, the Duster's Neutral engine load is higher than a proper gear.

[mayankk]

Originally Posted by ::CMS::

-------snip------ FYI, depending on the ECU map, atleast in my case, the Duster's Neutral engine load is higher than a proper gear.

What is the rpm in your dusters neutral ?

[Aroy]

Actually, taking your foot off accelerator consumes less petrol than coasting, as a miniscule amount (if any) is used in this condition.

Secondly if you are cruising at a constant speed, the fuel used is just enough to maintain the speed, that is minimum possible. If you coast and accelerate you will be consuming more fuel. As others have poinhted out there is more to driving than saving fuel. Engine breaking can save your life if you are caught unaware.

[mile201]

I think people may get away with switching to neutral on open roads (definitely not down hill) but its still a bad idea. As many have pointed out engine braking won't be available if you are in neutral, and if you have been in an accident you would know there is hardly any time to react. Would you rather be steering with both hands and trying to avoid a crash or fumble with shifting out of neutral when things get nasty? Also another thing that I worry about ( probably due to a history of driving old cars) is what if the engine dies when you are in neutral. It's a very panic inducing feeling when the power steering goes hard and breaks don't work as well. You can always shift to a gear..but I still think its an unsafe driving habit.

[Aroy]

Originally Posted by mile201

I think people may get away with switching to neutral on open roads (definitely not down hill) but its still a bad idea. As many have pointed out engine braking won't be available if you are in neutral, and if you have been in an accident you would know there is hardly any time to react. Would you rather be steering with both hands and trying to avoid a crash or fumble with shifting out of neutral when things get nasty? Also another thing that I worry about ( probably due to a history of driving old cars) is what if the engine dies when you are in neutral. It's a very panic inducing feeling when the power steering goes hard and breaks don't work as well. You can always shift to a gear..but I still think its an unsafe driving habit.

Also what happens if the brake fails just when you want it, and you have no engine breaking? On the whole coasting is tolerable at low speed on empty roads, but definitely dangerous on our highways at high speed.

[lapis_lazuli]

There is something called a DFCO (deceleration fuel cut off), in modern cars, which removes or minimizes fuel supply as soon as the foot is off the accelerator. It probably makes more sense to progressively downshift, instead of "floating" in neutral, pressing the clutch only to shift. So, "coast" in gear! This way, you save on the brake pads too !

[::CMS::]

Originally Posted by mayankk

What is the rpm in your dusters neutral ?

Sorry for the late reply, I am not getting any notification now a days.

RPM is somewhere ~800s

[mayankk]

Originally Posted by ::CMS::

Sorry for the late reply, I am not getting any notification now a days.

RPM is somewhere ~800s

By engine load, did you mean the fuel consumption, then?