[Dazzler]

I taught both of my girls not to do it when I was teaching them to drive.

Likewise, I never tried to teach my son what is an advanced technique fraught with danger if the driver is unable to properly understand it, let alone get it right.

And after 5 years of driving he has become a very capable driver. He changes gears exactly when and as required and even displays excellent understanding of traffic flow and reacts well ahead of time to situations - for which of course, I take credit.

Still I see no need to make any changes. Economy is not a biggie for him.

I don't see it as an advanced technique, just a dangerous technique.
It's not about getting it "right" because there is no way to get it right.
When you are travelling in a car at 60, 80 or 100 km/h or whatever, without it being in gear, the fact is you are not in control, the laws of physics are.
You can steer and you can brake but you need the full trifecta to have proper control.
Anyone can do it, but I just wouldn't recommend it as a safe driving practice.

I personally don't like the idea either.. I have never tried it (but doubt I ever will) 

I don't see it as an advanced technique, just a dangerous technique.
It's not about getting it "right" because there is no way to get it right.
When you are travelling in a car at 60, 80 or 100 km/h or whatever, without it being in gear, the fact is you are not in control, the laws of physics are.
You can steer and you can brake but you need the full trifecta to have proper control.
Anyone can do it, but I just wouldn't recommend it as a safe driving practice.

Dave, I take your point-of-view and I realise it will be that taken by most. Particularly when safety is suspected to be compromised but the safety card is what gets us all the draconian road rules designed for the lowest common denominator which is usually idiots who don't acknowledge the rules anyway.

Last word on coasting from me. Getting back into gear is less time and effort than changing gears. We all spend time out of gear in a manual when swapping cogs - no difference really.

Pip, I have no issue with you correcting what I say or taking me to task on the points I raised.

The quote I took from another website I did so as a block.  I provided the link to it below the quote.  I thought it best not to disect it. It was not meant to be totally relevant.

The idea of maintaining momentum is admirable and I do it whenever I drive, maintaining speed and increasing it downhill steadily to assist in propelling the vehicle up the next rise.  These are all recommended along with other similar techniques.  The link to the site I quoted from has a full range of great advice on Eco driving techniques and suggestions.

You are obviously keen on the idea of coasting, I'm not and I doubt if a driving instructor would advocate it.

I've done a Google of "coasting down hill to save fuel" search.  The results were interesting and provide interesting reading.  I won't elaborate bit I suggest it to anyone wanting more information.

Bob

[Doggie 1]

Fair comment Pip and I understand your point of view. 
But when changing gears you're only in neutral for a second, which is how it is designed to be.
When coasting, there's a much larger "window" for things to happen necessitating action.
I recall the truck disaster on Greenmount Hill a few years ago which resulted in a huge crash at the bottom of the hill.
Admittedly it was a truck and not a car, and he apparently "missed" a gear and ended up travelling in neutral all the way down the hill as he was unable to get it back into gear.
He just totally lost control and the resulting collision killed a few people including two sisters in one car.
It was a shocker and I remember their dad arrived at the scene because his girls hadn't arrived home and he went looking for them. 
Chalk and cheese, I acknowledge, but had he been in gear it wouldn't have happened.
And also, it's just the way I was taught so have always had that view. I just don't think it's worth the extra 0.1 l/100 kms you might get.

[Phil №❶]

Old car with a carburettor – take your foot off the accelerator pedal with the car in gear and fuel is still drawn through into the engine. Fuel savings could be made by coasting out of gear.

This is not quite correct,

At high speed if you take your foot off the accelerator, the throttle closes to idle and only idle quantity fuel, as metered by the idle jet, is sent to the inlet manifold. Taking the car out of gear at high speed will cause the engine to idle, which is the exact same amount of fuel from the idle jet, the idle jet simply won't allow more fuel to pass even with high revs and high vacuum, which is why the car slows down due to engine braking, so no benefit and many disadvantages IMO.

@Pip

I don't understand your comment and I will ignore the practice.

Been doing a bit more searching on the topic of coasting or freewheeling:

From page 82 of the 2012 ACT Road Rules Handbook
Link to full handbook: http://www.rego.act.gov.au/assets/PDFs/2012_ACT_Road_Rules_Handbook.pdf

Coasting, freewheeling and clutch control
NEVER coast or freewheel your vehicle with the clutch depressed or the gear lever in neutral.
Driving in gear helps your car to remain stable and keep a good grip on the road surface. When travelling downhill your engine can act as a brake if you drive in gear.
If you drive without the engine in gear you lose stability and control of your car’s speed, particularly while cornering. You may lose control and run off the road or roll over.
It is an offence to drive a vehicle unless you have proper control of it. If you drive with the clutch depressed for any distance (other than the last 2 or 3 metres when coming to a stop) you do not have proper control of your vehicle.

I also found mention in a NT learners document that reads:

Coasting
Any situation where a manual vehicle is travelling with engine not connected to driving wheels, whether by selection of neutral or by depressing the clutch. In this application, no coasting should be permitted until the car is almost stationary, whether downchanging has occurred or not. Automatics must remain in Drive, or other forward gear.

I also found mention of coasting as not permitted in two other state guides for learner drivers. 

One such example is from a NSW (Sydney) "A guide to the Driving Test".  It lists a number of situations that will mean a student will fail the test. Under Failing to maintain proper control of the vehicle is the following: "Clutch coasting (allowing the vehicle to roll along with your foot on the clutch) or coasting in neutral."

[Rochdale Pioneers]

I guess the "dangerous" comment relates to being able to power away from danger, because I can brake and steer the same in neutral as in gear. But if I'm cruising and need to floor it out of the wag I'll need a gear change. From neutral I'll need a gear change. The difference being.....?

[Doggie 1]

The difference being the legalities, I guess.
We have a charge here of "Not being in full & proper control of a motor vehicle" which I would contend would fit this scenario.

The difference being the legalities, I guess.
We have a charge here of "Not being in full & proper control of a motor vehicle" which I would contend would fit this scenario.

I'm sure there is also a similar charge in Australia for this scenario.  If I get the chance I shall ask our local police officer and report back.

[Doggie 1]

The difference being the legalities, I guess.
We have a charge here of "Not being in full & proper control of a motor vehicle" which I would contend would fit this scenario.

I'm sure there is also a similar charge in Australia for this scenario.  If I get the chance I shall ask our local police officer and report back.

I'm in Australia.
W.A. has that law so I presume other state & territories would have similar legislation.
It is generally used for people driving cars with kids on their laps, or dogs on their laps, etc (yes, it does happen) but I see no reason why it couldn't be used in this case, if the evidence was available.

[vatazhka]

Looking at both OBD and dash fuel consumption meters convinced me that coasting in neutral and with clutch depressed gives you nothing with regard to fuel savings. Fuel supply only gets shut when driving with gas pedal depressed when in the right gear (you need to maintain more than ~1500 RPM). Otherwise you're wasting fuel. Actually, when in neutral you'll burning up way more than when driving in the 3rd gear!

I agree with you vatazhka.  As I've said before, no point in coasting, which is dangerous, when no fuel is used with a fuel injected engine when foot is off the accelerator, unless the engine starts to pull the vehicle forward via the anti-stall feature or the driver depresses the accelerator.

If you have a MAP gauge (such as Scangauge II), this can be used as a fuel saving guide.  Simply drive with as low as is possible turbo boost can save fuel.  Keep the boost low when possible and when needed, keep it steady and minimal.  Planting the foot gets excessive boost and increases fuel usage.

[mjt57]

For better fuel consumption, be careful where, when, how you use the Cruise Control.
CC doesn't think ahead for hills so it doddles along happily until the car starts to loose speed on the uphill and then slams down a gear or two in a mad dash to maintain the set speed.

For some reason mine doesn't seem to do this...

Having said all that, I am often happy to sacrifice any fuel saving for the benefits in staying under the speed limit and being able to devote my concentration to other things (like the idiots around me in the traffic and the road conditions).

Is it a good idea to stay in CC mode when in traffic, particularly heavy traffic?

As for fuel consumption, the minute I get onto the freeway, I hit CC. I can travel for about 120 km before I need to get off of it in order to safely navigate through city traffic.

Last big trip saw the fuel consumption meter dip below 5l/100km for the first time (4.9).

As for hills, the CRDi handles them with ease, in 6th, CC mode active. In contrast my Mazda Tribute (3.0l V6 petrol, 3sp/overdrive auto) is terrible. Get to a reasonable hill, it slows from a set 110 kays to around 100, kicks back a gear or two revs the crap out of itself and accelerates to over 120 kays before backing off. I have to manually deselect overdrive before I approach the hill...

In any case, I've given up trying to drive for economy. Around town i'm getting around 5.8, 4.9-5.0 on a trip. These figures in themselves are pretty good.

I drive where I feel the engine is at is most comfortable, not revving the bags out of it, not laboring it. Usually means gear changes at around 2,000-2,500 rpm, or wherever it feels comfortable to do so without looking at the tacho (a practice in itself that could be construed as "driver distraction".) Certainly, in city traffic I don't care as I'm more focused on not getting involved in any collisions...

[rustynutz]

For better fuel consumption, be careful where, when, how you use the Cruise Control.
CC doesn't think ahead for hills so it doddles along happily until the car starts to loose speed on the uphill and then slams down a gear or two in a mad dash to maintain the set speed.

For some reason mine doesn't seem to do this...

Something to do with it being a manual perhaps? 

[mjt57]

Something to do with it being a manual perhaps? 

Could be...

 

[rustynutz]

Come to think of it, I'm actually a bit concerned that surferdude's i30 does it.... 

[Just Rick]

Interesting thread,some interesting comments,I only have one thing to say about coasting,lets all take our driving test again and see if any of us pass if at any point in the test any of us coast in nuetral,I think not.

It is called angel gear for a reason

Interesting thread,some interesting comments,I only have one thing to say about coasting,lets all take our driving test again and see if any of us pass if at any point in the test any of us coast in nuetral,I think not.

You always seemed like a guy who was happy to push against the establishment. Me, on the other hand, most people would say not. However, in this point I'm happy to push the line that because most people cannot safely determine when and if "coasting" is useful, sensible or even safe then like lots of road (and other rules), we need to assume most of us are stupid.

I like to think I'm not and can tell the difference well enough to see that coasting (in any form, in or out of gear) is only unsafe for those that are not able to control their vehicles in all conditions. Sadly, that is most of us.

[Just Rick]

Interesting thread,some interesting comments,I only have one thing to say about coasting,lets all take our driving test again and see if any of us pass if at any point in the test any of us coast in neutral,I think not.

You always seemed like a guy who was happy to push against the establishment. Me, on the other hand, most people would say not. However, in this point I'm happy to push the line that because most people cannot safely determine when and if "coasting" is useful, sensible or even safe then like lots of road (and other rules), we need to assume most of us are stupid.

I like to think I'm not and can tell the difference well enough to see that coasting (in any form, in or out of gear) is only unsafe for those that are not able to control their vehicles in all conditions. Sadly, that is most of us.

Like Dave pointed out in reply 93,yes this was a heavy vehicle but the principals are the exact same thing no matter the size of the vehicle,all parts are all relevant in size to the size of the vehicle,the example Dave also pointed out had far more facts that where never brought out to the public behind it,only reason I know of them is I knew and worked for Friends of the trucks owner,there was far more to this just than missing a gear,but again the principal is the same,in neutral in certain circumstances you do not have full control,I have missed gears on decent of hills,mountains again in a heavy vehicle and it is not a pleasant situation to be in,knowing that you have lost control.

Yes I very occasionally coast a vehicle,but I am within feet of stopping,maybe I am to old school to understand the logic of someone wishing to partake of this practice,maybe I am just someone who has lost control of a vehicle because of being in Angel gear and it is called Angel gear for a very good reason.

debate is good we all have our own opinions,though I do not condone coasting(I should add here,if you are in gear,technically you can never coast,you are either decelerating,cruising or accelerating),it would not be the unsafest driving practice I see on the road on a daily basis

[Aussie Keith]

I noticed coasting down a hill recently the car may have disengaged the gearbox as engine speed dropped to an idle during the descent. If this is in fact what happened then possibly manual hypermiling techniques may not be as necessary.

[Dazzler]

I noticed coasting down a hill recently the car may have disengaged the gearbox as engine speed dropped to an idle during the descent. If this is in fact what happened then possibly manual hypermiling techniques may not be as necessary.

That is interesting Keith! Seems a bit strange though 

[paul]

 The topic was Hypermiling techniques.

IF  the fuel was "cut off" the engine would stop !
in neutral my car ticks over, so must be getting fuel.
it has never turned off ?
we all know about engine braking,  but if the hill you are coasting down allows
a "constant" speed to be maintained, without the use of brakes, leaving it in gear
would decrease your constant speed requiring extra fuel later on !
I would not coast with my foot on the clutch either as it will wear the thrust bearing.

yes I agree it is possibly safer left in gear, but in Hypermiling, engine braking can sometimes be the enemy.

[Dazzler]

yes I agree it is possibly safer left in gear, but in Hypermiling, engine braking can sometimes be the enemy.

Good point, I can see where you are coming from! <Brighton> 

[agentr31]

This thread IMHO is the most pointless, waste of time thread on the whole forum, and it should be locked then deleted, anyone making mention of hypermiling or being a tight ar5e (because lets face it that's what it boils down to) should be banned for life.

hypermiling, get in car, sit down, wind window down, pull keys out, throw them out of window, walk, there is your fuel savings.

You bought it to use, you bought it because it ALREADY is fuel efficient compared to that VS commodore, enjoy it, want more fuel efficiency? buy a push bike.

[Phil №❶]

I agree that hypermiling is a dangerous practice, involving irresponsible driving techniques. But not locking and deleting the thread, rather educate people, to the dangers involved and that's MHO.

[paul]

This thread IMHO is the most pointless, waste of time thread on the whole forum, and it should be locked then deleted, anyone making mention of hypermiling or being a tight ar5e (because lets face it that's what it boils down to) should be banned for life.

hypermiling, get in car, sit down, wind window down, pull keys out, throw them out of window, walk, there is your fuel savings.

You bought it to use, you bought it because it ALREADY is fuel efficient compared to that VS commodore, enjoy it, want more fuel efficiency? buy a push bike.

I don't know the price of fuel in OZ but its so expensive here I will save what I can , if it means coasting down hills what the hell,
I am 60 yrs old and have done it most of my life (without causing or having accidents) I also avoid braking when not needed and riding the clutch.
you obviously have money to burn, buy a nice v8 gas guzzler, I would if I could afford it.

[AlanHo]

I too now drive frugally - but never indulge in coasting which is unnecessary in a diesel to save fuel - on the over-run no fuel is delivered to the engine. If you coast a diesel the engine is then idling and using fuel.

I have found that the cruising sweet spot for economic cruising with my car is between 55 mph and 60 mph. Cruise at above 65mph and the economy suffers by at least 6%. This is unfortunate because on a busy motorway it puts you with the lorries in the first lane - so in those circumstances I break my rule and cruise at a slightly higher speed. I rarely use cruise control nowadays - I have managed to convince myself that it hits economy slightly.

I check my tyre pressures weekly and keep them at 37 psi, accelerate gently, chose a gear to keep the engine spinning at 1750 to 2000 rpm, keep weighty clutter out of the car and drive with all windows closed.

If you call this hypermiling - so be it.

[agentr31]

I don't know the price of fuel in OZ,

you obviously have money to burn, buy a nice v8 gas guzzler, I would if I could afford it.

98 RON is today 182.9c/L.

Sort of, what I put away after expenses is there to have fun with.

No, it would be nice but I have a turbo charged 3L skyline i'm putting on the road.