To Coast or Not To Coast.......

[Teejay]

With the dsg you don't have to touch the brakes, simple move the stick to manual mode engine braking begins. Return to suyo for coast.

 

[Taff7996]

Dont have to braking to turn coast function off,

If you have the sports steering wheel option (with flappy paddles)You don't need to touch the brakes to disengage the coast function.
You just simply pull the left hand paddle back once, it will disengage the coast function and put it back into gear

 

[B J G]

With the battery charging (engine & leisure) system relying on the regenerative method during de-acceleration how can it function during Coasting Mode?

 

[kave]

I have also stopped using the coasting function by disabling it. I think the constant engage and disengage is nothing that live extend the life of the gearbox and clutch.
For the same reason I normally don't use start/stop either, except when I know it will be a longer stop.

 

[B J G]

1. That depends on the competence of the driver.

2. That depends on the competence of the driver.

3. That depends on the competence of the driver.

4. Compared to the cost of a gearbox/clutch modern brake pads and discs are cheap.

5. The California uses Electric Fans and anyway a Diesel engine has problems keeping warm.

6. Unless actually braking the Coast function can be disabled by moving the brake peddle a few mm's without activating the brakes themselves and hence the rear brake lights. Separate pressure activated switch for brake lights.

7. You can if you wish.

Hi WelshGas belated response.

1-2-3 My point exactly as that it requires additional driver awareness and possible problem areas.

4. Clutches and gearbox have to engage/disengage for coast to function, extra operations.
Never had a gearbox or clutch fail due to vehicle having no coast function personally.

5. Euro 6 diesels have to run at near critically high temperatures to achieve fuel burning efficiency.
I was referring to the mechanical water and oil pump flow rates being cut instantly when the engine is at max temp.
I watched the oil temp during a Coasting run in France and noticed that the oil temp would go up to 107 degrees when coasting, not good with long service intervals. dropped down quickly when coasting
disengaged.
I assume no oil cooler fitted such as Land Rovers and HGVs have.

6 Can't comment as no knowledge of dual switching method on brake pedal operation. Did find that a touch on accelerator pedal had the same effect. Not sure how to tell that brake lights aren't being operated during normal driving.

7. Please clarify how coast can be made to operate during cruise mode.

 

[WelshGas]

Hi WelshGas belated response.

1-2-3 My point exactly as that it requires additional driver awareness and possible problem areas.

4. Clutches and gearbox have to engage/disengage for coast to function, extra operations.
Never had a gearbox or clutch fail due to vehicle having no coast function personally.

5. Euro 6 diesels have to run at near critically high temperatures to achieve fuel burning efficiency.
I was referring to the mechanical water and oil pump flow rates being cut instantly when the engine is at max temp.
I watched the oil temp during a Coasting run in France and noticed that the oil temp would go up to 107 degrees when coasting, not good with long service intervals. dropped down quickly when coasting
disengaged.
I assume no oil cooler fitted such as Land Rovers and HGVs have.

6 Can't comment as no knowledge of dual switching method on brake pedal operation. Did find that a touch on accelerator pedal had the same effect. Not sure how to tell that brake lights aren't being operated during normal driving.

7. Please clarify how coast can be made to operate during cruise mode.

4. Have you ever had/heard of a Gearbox/Clutch/DSG failing because of the Coast Function?
5. Disagree. Modern oils used run at higher temperatures and the temperature changes you might get engaging Coast are well within tolerance levels.
6. Get someone to follow you and report on Brake Light Function. My son did it with me. No light with mm movement of brake.
7. Coast doesn't actually work with Cruise as on a downhill section the road speed will drive the engine although fuel flow will be cut to give engine braking, but switch off cruise and Coast engages on a downhill section.

The Coast function, or equivalent has been around for a long time on numerous vehicles both cars and HGV's with no detrimental effect, just like Stop/Start . Upto you whether you use them but they are there to reduce exhaust emissions and improve fuel economy. Every little bit helps.

 

[GrannyJen]

I'm not getting into any arguments. I like coast.

Simplicity itself. Lift off, and it runs forever on inertia, the minimum tap on the brake pedal then engine braking kicks in, the minimum tap on the accelerator and coast kicks back in. The choice is entirely down to the driver when to coast and when not to with minimum fuss, minimum thought and no measurable impact on anyone else. I love it.

 

[B J G]

4. Have you ever had/heard of a Gearbox/Clutch/DSG failing because of the Coast Function?
5. Disagree. Modern oils used run at higher temperatures and the temperature changes you might get engaging Coast are well within tolerance levels.
6. Get someone to follow you and report on Brake Light Function. My son did it with me. No light with mm movement of brake.
7. Coast doesn't actually work with Cruise as on a downhill section the road speed will drive the engine although fuel flow will be cut to give engine braking, but switch off cruise and Coast engages on a downhill section.

The Coast function, or equivalent has been around for a long time on numerous vehicles both cars and HGV's with no detrimental effect, just like Stop/Start . Upto you whether you use them but they are there to reduce exhaust emissions and improve fuel economy. Every little bit helps.

Not a case of arguing merely various other points and views.

4. Point I made was that the engine reduces brake wear and at no cost.
HGV's have engine braking to reduce brake wear.

5. Previous BMW had an Oil temp gauge as opposed to water temp and that never went over 100 degrees.
Oil cooler on my old petrol sports car keeps the oil temp under 80 degrees.
Just me probably but I don't like oil temp higher than water temp.

6. OK if it works for you.

7. That was what I said "coast doesn't work on cruise mode". From your initial reply I thought that you said that it could be done.

Never had coast on any of the HGV's that I operated. Seem to recall old vintage ones having it though.
I tend to think that the coast function is for VW to get the emissions level down, in conjunction with low rolling resistance tyres, to acceptable test levels.

I've seen fuel savings with coast engaged but equally similar figures with economy driving. Perhaps coast function would be better on a button like stop/start rather than preselecting on or off

 

[zerofour]

When we picked up our van coast was enabled. After initially disliking it (I found I wasn't able to use engine braking as much as I wanted) I switched it off. Since becoming more used to DSG and reading this thread I have enabled again – I think I'll leave it on as there is minimal engine braking with DSG anyway (unless I use in manual mode).

 

[WelshGas]

Not a case of arguing merely various other points and views.

4. Point I made was that the engine reduces brake wear and at no cost.
HGV's have engine braking to reduce brake wear.

5. Previous BMW had an Oil temp gauge as opposed to water temp and that never went over 100 degrees.
Oil cooler on my old petrol sports car keeps the oil temp under 80 degrees.
Just me probably but I don't like oil temp higher than water temp.

6. OK if it works for you.

7. That was what I said "coast doesn't work on cruise mode". From your initial reply I thought that you said that it could be done.

Never had coast on any of the HGV's that I operated. Seem to recall old vintage ones having it though.
I tend to think that the coast function is for VW to get the emissions level down, in conjunction with low rolling resistance tyres, to acceptable test levels.

I've seen fuel savings with coast engaged but equally similar figures with economy driving. Perhaps coast function would be better on a button like stop/start rather than preselecting on or off

60,000 miles and still have 50% brake pads present.

Oil temperatures above water temperatures are a must in modern engines to get rid of the adsorbed water from the atmosphere which degrade their lubricant capabilities.

If you don't feel comfortable using the Coast function then don't use it.

All these reasons you are putting forward are utterly spurious. Yes, it together with Stop/Start are all designed to lower emissions and hence improve economy. If there is a T7 with a Diesel engine then they will probably be a permanent feature.

 

[B J G]

60,000 miles and still have 50% brake pads present.

Oil temperatures above water temperatures are a must in modern engines to get rid of the adsorbed water from the atmosphere which degrade their lubricant capabilities.

If you don't feel comfortable using the Coast function then don't use it.

All these reasons you are putting forward are utterly spurious. Yes, it together with Stop/Start are all designed to lower emissions and hence improve economy. If there is a T7 with a Diesel engine then they will probably be a permanent feature.

Notice that you aren't driving a Euro6 engine.

 

[WelshGas]

Notice that you aren't driving a Euro6 engine.

Nope, 180 biturbo, still Coasts and has Stop Start. All works the same.

 

[B J G]

Nope, 180 biturbo, still Coasts and has Stop Start. All works the same.

Engine completely different with all the emission controls. I've seen various problems with oil consumption on your 180 engine, any connection to coast or stop start. Doubt it but..

I'm not disagreeing with you on the principal of fuel economy and see it's now on the Golf.

 

[WelshGas]

Engine completely different with all the emission controls. I've seen various problems with oil consumption on your 180 engine, any connection to coast or stop start. Doubt it but..

I'm not disagreeing with you on the principal of fuel economy and see it's now on the Golf.

No. the 2010/2011 CFCA engines had a production fault , in some of the engines, not all, that resulted in high oil consumption at 60,000 or so miles. Nothing related to Coast or Stop/Start functions.

 

[B J G]

Had a look through Google and found various discussions on Coasting Mode for Skoda, VW etc.

Like on here some like it and others don't. Many seem to think that fuel saving is questionable over what driving practice can achieve.

My personal view is that it should be selectable when on the move to enable engagement when conditions are suitable.
Having to preselect before a journey with the levels of traffic I usually encounter means that I have it switched off and don't want to stop just to put it on.

 

[Trebor]

Had van for about a week before I found out about coasting which was switched off . Use coasting all the time now reminiscent of my old Saabs which had freewheel . When I'm going down a steep hill I just switch to manual to get engine braking and control how much braking with the gears . I found dsg was in too low a gear if I touched the brake .

 

[Ocean Spirit]

My personal view is that it should be selectable when on the move to enable engagement when conditions are suitable.

Merry Christmas BJG (and every one)
I like the function and find it easy to select/deselect on the move as required.
When ever I no longer need the accelerator i remove my foot and I coast.
When I need engine braking instead I remove my foot then at an instinctive moment I dab the brakes and from either of these two conditions returning to acceleration is the same.
To my mind it is selectable or ignoreable every second you are driving.

 

[GrannyJen]

Had a look through Google and found various discussions on Coasting Mode for Skoda, VW etc.

Like on here some like it and others don't. Many seem to think that fuel saving is questionable over what driving practice can achieve.

My personal view is that it should be selectable when on the move to enable engagement when conditions are suitable.
Having to preselect before a journey with the levels of traffic I usually encounter means that I have it switched off and don't want to stop just to put it on.

It is selectable on the move. I have no problem engaging or disengaging whenever I want to.

 

[Bill R]

Still a new Cali driver so point out if I'm wrong please , but worth knowing that if you're a big user of the ACC, it stays in a gear and doesn't appear to utilise the coasting function .

 

[GrannyJen]

Still a new Cali driver so point out if I'm wrong please , but worth knowing that if you're a big user of the ACC, it stays in a gear and doesn't appear to utilise the coasting function .

Yes, that's right. If I wanted to engage coast then click ACC off first then a light dab of the accelerator.

 

[WelshGas]

Still a new Cali driver so point out if I'm wrong please , but worth knowing that if you're a big user of the ACC, it stays in a gear and doesn't appear to utilise the coasting function .

If it didn’t then you wouldn’t have engine braking available for small decreases in speed.

 

[soulstyledevon]

Oddly
Members from the T6 forum have reported that coasting has increased fuel consumption...???

I am conducting my own experiment. Coasting has been on since I bought the van and I have tracked fuel consumption over the last 3 months.
At my last refill, I have disabled coasting and will see what mpg the van returns with it disabled.

 

[B J G]

Merry Christmas BJG (and every one)
I like the function and find it easy to select/deselect on the move as required.
When ever I no longer need the accelerator i remove my foot and I coast.
When I need engine braking instead I remove my foot then at an instinctive moment I dab the brakes and from either of these two conditions returning to acceleration is the same.
To my mind it is selectable or ignoreable every second you are driving.

Longggg delayed answer

I was referring to the MFD selection of Coasting on or off not the making it temporarily disengage on the move.

 

[Ocean Spirit]

Longggg delayed answer

I was referring to the MFD selection of Coasting on or off not the making it temporarily disengage on the move.

I see,
As you point out it's been so long since since the conversation I haven't got a clue whether I realised that at the time.
I get your point for sure this time.
But with the ability to disengage/re-engage on the run with foot control I may well have understood before and felt with it 'selected' on the MFD before a journey and the fact you are able to disengage why do you need another means of 'selectable'.

Any way have you decided which you prefer yet? i.e which do you leave it in most. Selected or Not Selected pre journey?

 

[B J G]

I see,
As you point out it's been so long since since the conversation I haven't got a clue whether I realised that at the time.
I get your point for sure this time.
But with the ability to disengage/re-engage on the run with foot control I may well have understood before and felt with it 'selected' on the MFD before a journey and the fact you are able to disengage why do you need another means of 'selectable'.

Any way have you decided which you prefer yet? i.e which do you leave it in most. Selected or Not Selected pre journey?

Don't use it at all as I prefer to have the engine running/engaged as in cruise condition with some engine braking which isn't that much. I also don't like the engine going to idle when it may have been working hard and very hot on an uphill drag.
If there was a simple switch as in is the case with the stop/start function I'd probably use it on some runs.

I wonder how many times drivers disengage it by touching a pedal in percentage terms when it goes into coasting mode.

Another puzzle for me is that if using coasting how can regenerative energy be produced?