Think of the Eco mode like the freewheel on a bicycle which enables you to coast downhill without losing speed or gradually lose speed on the flat without turning a pedal

I'm not sure what a maxidot displays in mpg mode but in my L/100 mode when the car is stationary and ticking over then it displays instant consumption in L/hour.

My 2014 Australian 1.4tsi (manual) does not have stop/start and the typical displayed value at tickover (700rpm) when stationary, with no ancillary loads, is 0.5L/hour.

If I raise the revs to 2000rpm and hold it there then consumption rises to 1.5L/Hour

Let's assume an idealised situation where you are going down a long gentle gradient sufficient to maintain 100kph and the gearbox in eco mode is coasting and the revs are at idle (so consuming 0.5L/hour) then you are achieving 0.5L/100 or 565mpg.

If you were not in eco mode and the gearbox holds 7th gear then there would be a mild braking effect from the engine and it might be necessary for a small amount of throttle to maintain 100kph at around 2000rpm (?) then consumption would be 1.5L/100 or 188mpg.

 

Of course if the hill is a bit steeper and need to engage gears to hold speed back to 100kph then there is no fuel consumed.

 

So there are benefits from Eco mode and coasting but they are specific to certain circumstances but can make a surprising difference to actual consumption if used intelligently in slow moving and surging traffic conditions.

 

Coming back to my cycling analogy I think it will make sense to those who have experience riding a fix-wheel bike and one fitted with a freewheel.

 

Edited 21 December, 20178 yr by Gerrycan

Cheers Gerry,

 

I will try making sure aircon, seats, blowers etc are switched off and see what kind of reading I get on my Infotainment/LCD screen traveling along a given stretch of road (with and without Eco mode).  It probably works well on the 1.4 TSI and I gather your engine is surprisingly fuel efficient and nifty enough when in a Skoda Octy.  Interested to see what it does in a 2ltr diesel Superb.

1 hour ago, Muff said:

Yes rtj your post about the DSG box going into Neutral coasting along in idle when in Eco Mode figures. Still not sure how much fuel this is Eco mode engine coasting business is going to save?  A small amount I guess, particularly if you already drive the car conservatively, read the road ahead and avoid unnecessary  sudden acceleration or braking etc...

 

It was my understanding that with modern engines lifting off the throttle in gear can be more efficient than coasting in neutral.  In neutral the engine needs to stay at idle speed to prevent it from stalling so fuel still needs to be injected into the cylinders whereas lifting off the throttle in gear can allow the engine to essentially free run without any fuel being injected as it'll continue to turn over from the wheels turning the drive shaft.

Eco mode hasn't really saved me any consumption. It  makes for slightly more comfortable stop/start/slow progress in traffic as the car coats instead of staying fully in gear. You need to learn how to use it. It engages when you take your foot from the accelerator and drops back to gear if you touch the brake or if going downhill the car starts to over run. However a quick blip, and I do mean blip, and it reengages. You will be surprised just how far it will 'coast' on level ground. Gear change positions are very relaxed.

All in all I use it when I feel the need to sit back and relax rather than for economy  purposes.

 

hth 

1 hour ago, Gerrycan said:

Think of the Eco mode like the freewheel on a bicycle which enables you to coast downhill without losing speed or gradually lose speed on the flat without turning a pedal

I'm not sure what a maxidot displays in mpg mode but in my L/100 mode when the car is stationary and ticking over then it displays instant consumption in L/hour.

My 2014 Australian 1.4tsi (manual) does not have stop/start and the typical displayed value at tickover (700rpm) when stationary, with no ancillary loads, is 0.5L/hour.

If I raise the revs to 2000rpm and hold it there then consumption rises to 1.5L/Hour

Let's assume an idealised situation where you are going down a long gentle gradient sufficient to maintain 100kph and the gearbox in eco mode is coasting and the revs are at idle (so consuming 0.5L/hour) then you are achieving 0.5L/100 or 565mpg.

If you were not in eco mode and the gearbox holds 7th gear then there would be a mild braking effect from the engine and it might be necessary for a small amount of throttle to maintain 100kph at around 2000rpm (?) then consumption would be 1.5L/100 or 188mpg.

 

Of course if the hill is a bit steeper and need to engage gears to hold speed back to 100kph then there is no fuel consumed.

 

So there are benefits from Eco mode and coasting but they are specific to certain circumstances but can make a surprising difference to actual consumption if used intelligently in slow moving and surging traffic conditions.

 

Coming back to my cycling analogy I think it will make sense to those who have experience riding a fix-wheel bike and one fitted with a freewheel.

 

 

I agree. When coasting in gear I get a lot of engine braking on my 280. When coasting in Eco, it's amazing how it retains speed and the distance it goes. To achieve the same speed over the same distance when in gear would require some level of throttle input. If you judge it right, you can roll everywhere. I've been driving like this for years! It's quite fun - say I'm going between a couple of roundabouts a mile or so apart, I'll give it some beans initially and thoroughly enjoy the acceleration as the mpg plummets, then roll the rest of the way to the next roundabout. By the time I get there, the mpg is back to where it would be if I'd just driven sensibly!

Saga lout.  I can guess exactly how you came by that name. I have also recently qualified but I still haven't grown up.  However if you want to sit back and relax Comfort mode is good. Just don't plan going round corners too fast.

Do you have many corners that you need to go round at more than 60mph or even 70 mph?, because even in ECO mode a Superb can do that speed and more

go into the corner and exit them. and still be going with the flow of something like a Skoda Citigo with all of 60PS.

 

I think the Eco mode setting on DSG cars is a backside covering exercise.  When you next start the car the gearbox goes to drive and you have to manually choose the gearbox to Eco.  I believe this is because it means you have to choose to disengage the gearbox and coast rather than  the car starting it as if there is no engine braking it will take you longer to slow down.  If there was an accident and the engine coasting could be blamed, Skoda could be liable, whereas if you have to choose to select Eco coasting, any accident would be down to you.

On 21/12/2017 at 13:30, Gerrycan said:

Think of the Eco mode like the freewheel on a bicycle which enables you to coast downhill without losing speed or gradually lose speed on the flat without turning a pedal

I'm not sure what a maxidot displays in mpg mode but in my L/100 mode when the car is stationary and ticking over then it displays instant consumption in L/hour.

My 2014 Australian 1.4tsi (manual) does not have stop/start and the typical displayed value at tickover (700rpm) when stationary, with no ancillary loads, is 0.5L/hour.

If I raise the revs to 2000rpm and hold it there then consumption rises to 1.5L/Hour

Let's assume an idealised situation where you are going down a long gentle gradient sufficient to maintain 100kph and the gearbox in eco mode is coasting and the revs are at idle (so consuming 0.5L/hour) then you are achieving 0.5L/100 or 565mpg.

If you were not in eco mode and the gearbox holds 7th gear then there would be a mild braking effect from the engine and it might be necessary for a small amount of throttle to maintain 100kph at around 2000rpm (?) then consumption would be 1.5L/100 or 188mpg.

 

Of course if the hill is a bit steeper and need to engage gears to hold speed back to 100kph then there is no fuel consumed.

 

So there are benefits from Eco mode and coasting but they are specific to certain circumstances but can make a surprising difference to actual consumption if used intelligently in slow moving and surging traffic conditions.

 

Coming back to my cycling analogy I think it will make sense to those who have experience riding a fix-wheel bike and one fitted with a freewheel.

 

Your assumption of fixed fuel consumption at 2000rpm is wrong since it will be less than the stationary situation when going downhill but more if maintaining 2000rpm uphill.

2 hours ago, PSM said:

Your assumption of fixed fuel consumption at 2000rpm is wrong since it will be less than the stationary situation when going downhill but more if maintaining 2000rpm uphill.

 

If wooyay is right, there's no fuel injected into the engine when coasting in gear.  But by applying a a bit of throttle to maintain the speed / distance that neutral coasting gives you, clearly some fuel is going to be injected. Is that going to be more than the amount required to idle the engine? I'm guessing 'yes', because at idle only enough fuel is injected to overcome losses at idle speed. At something above idle, as with coasting in gear, the losses are higher, so more fuel needs to be injected to overcome them. Clearly, the losses that occur by the wheels having to drive the engine when going downhill in gear are higher than if you don't have to drive the engine (neutral coasting). I know that because I don't go as far or as fast when coasting in gear. The question is, does it take more fuel to overcome those losses than to idle the engine. I think yes and so does my mpg meter, but feel free to correct me, I'm no physicist!

If you coast down hill with the DSG in E mode (i.e. engine idle) the car might even accelerate downhill. Do it in gear and engine braking will cause deceleration. It will go quiet some way on a flat road when coasting in E mode.... but not if you have cruise control on.

45 minutes ago, rtj70 said:

If you coast down hill with the DSG in E mode (i.e. engine idle) the car might even accelerate downhill. Do it in gear and engine braking will cause deceleration. It will go quiet some way on a flat road when coasting in E mode.... but not if you have cruise control on.

 

There's another option I'd like - cruise control that doesn't apply brakes.

4 minutes ago, YTT said:

There's another option I'd like - cruise control that doesn't apply brakes.

 

Why? Until I got the Superb I'd not had ACC before.  I think it's great. Combined with active lane assist it is excellent in my opinion.

Edited 22 December, 20178 yr by rtj70

3 minutes ago, rtj70 said:

 

Why? Until I got the Superb I'd not had ACC before.  I think it's great. Combined with active lane assist it is excellent in my opinion.

 

Because in my last car, cruise only controlled the throttle. In reality that means that if you hit a minor downhill section, the car just coasts in cruise rather than brakes. You gain a bit on the car in front (if there is one), but 9 times out of 10 you don't get too close and you don't gain excessive speed. When it flattens out, normality is resumed. With braking, the bloody thing is constantly bleeding off energy unnecessarily to keep the speed at precisely the set value.

There is no fuel injected when you take your foot from the pedal. The resistance that we call engine braking is the opposing force on the pistons caused by the fuel intake being shut off and the engine still being connected to the wheels.  So as gerrycan says if you are going downhill then gravity and inertia is what is 'driving' you forwards against that resistance. So zero fuel consumption. 

When 'coasting' fuel injection continues albeit at an 'idle' or thereabouts consumption rate so you are using fuel.

 

The real benefit of 'coasting' comes from using the gravity and inertia from the point that you start to 'coast' to maximum advantage. So there is a crossover point (which I do not intend to calculate here!!) at which the distance travelled in 'coast' becomes more economic than driving in gear. I think I recall that the owners manual has some words to that effect about when best advantage can be gained but I am not going to trawl thru the 300 pages to find it now  

 

What that means in practice is that you know the roads you drive, or can see opportunities to benefit on other roads, and can choose to use the 'eco' facility when you see an advantage in doing so. That is why it is an option and not  default position; nothing to do with liabilities or responsibility for accidents etc.

 

The other thing to mention about modern dsg  coasting is that it is much safer than the old 'kick it out' manual coasting. For example, a simple touch on the brake pedal, which is a natural response to say increasing speed, and you are back in a matched gear without any issues.    

People talk about 'ECO Mode as though all are equal, 

there are much differences on the various petrols or diesels or even petrols with ACT / COD, then different DSG's, and Manual boxes.

 

Then this is about as up to date the VW Group get to.

 

Edited 23 December, 20178 yr by AwaoffSki

I've just read that Mini ( BMW?) have developed new double clutch gearboxes to be installed on some models that will include a coasting/freewheeling feature so it is not just VW that see potential in the feature.

 

However I will repeat my opinion that the benefits of freewheeling require a quite specific set of circumstances that do not necessarily suit everybody's driving style or driving environment.

I also think that the benefits of freewheeling are probably compromised by running ancillaries such as air-con and/or heated whatevers that increase the idle load on the engine.

 

I consider my 1.4tsi idle displayed consumption of 0.5L/hour as quite remarkable (as a typical example of the type) having experienced displays on large engine Australian hire cars (3 to 4 litre and 6 cylinders) of around 2L/hour at idle.

It is also worth mentioning that my mk3 Octavia is the first vehicle I've owned or even driven that is incapable of providing sufficient engine braking to avoid exceeding the speed limit on long, but not especially steep (12%-ish) local hill, and I am talking about a 90 kph limit and revving its little a**se off in 2nd gear.

So I do understand the argument from those that say that it is not generally worthwhile freewheeling for economy

 

Edited 23 December, 20178 yr by Gerrycan

The Coasting modes were in DQ200 DSG a good few years back, but there as 'Owner Testing' and not made a feature of.

 

Maybe go try the very latest of TDI / SCR / DSG with Stop Start, Auto Hold, Electric Handbrake, Coasting Function and not even Cruise Control and see just how good 'Coasting can be'.

 

Obviously it requires the driving style or circumstance to be right, but sometimes just in 'D' and no special settings can be enough.

 

PS 

Latest Autobox with paddles on the MINI Cooper S JCW and others is a cracking traditional Auto, 

as is the Toyota GT86 / Subaru BRZ Auto IMO.

 

 

Coasting Function, fan dabi dozi IMO. 

but then it was on a Fabia Mk2 vRS as well but just never showed as 'coasting' but it was.

Edited 23 December, 20178 yr by AwaoffSki

The funny thing I'm not sure the freewheeling feature on the DSG would have contributed anything to the official consumption tests on the indoor rolling roads.

The VW 'economical driving guides' even say there is potential for improving on the official results by freewheeling (use of clutch on manuals).

'Featuring' in the Investigations as being part of the 2nd Defeat Device found on Audi, VW, Porsche as using the DSG to cheat testing.

 

That is in the USA and Europe.

U.S. regulator found another cheat device in Audi car_ report.mhtml

Edited 23 December, 20178 yr by AwaoffSki

15 minutes ago, AwaoffSki said:

'Featuring' in the Investigations as being part of the 2nd Defeat Device found on Audi, VW, Porsche as using the DSG to cheat testing.

 

That is in the USA and Europe.

It would be interesting to see how that cheat works, because as far as I'm aware the official tests always favoured an auto box because all the driver of the auto had to do was follow the test course profile and let the box do its thing. Whereas the driver of the manual had to change gear at specific rev points, with specifics on what gear, the time in each gear, acceleration rates and how long the gear change operation should take... while following the course profile.

So an eco mode in an auto, with early gear changes, would be huge beneficial for the overall test results, but I'm not sure that constitutes as cheating, so obviously there must be something else afoot.

Edited 23 December, 20178 yr by Gerrycan

EU Testing that the USA and Australia accepted was always a con, allowing Manufacturers to give their Test Results from Their or others Test Establishments.

There was not supposed to be Diesel put in Engine OIl or Over Inflated tyres, 

and VW were caught with Implausible / Irregular test results not just from the Defeat Device Scandal.

Hence new Co2 g/km figures in 2016 on some Euro 6 Petrol & Diesels.

Skoda was not implicated in it though, just VW, Audi & SEAT.

ie Different Test Facilities, or was that Employees present?

http://skoda.co.uk/pages/fuel-consumption-statement.aspx 

 

We will see what happens now in the EU with the Real World Testing on new Type Approved vehicles.

I think the freewheel is just another gimmick. I'm sure that some people get interested in modifying their driving to make the most of it but I really can't believe the fuel saving is significant. If money saving was your goal you could profitably save more by turning off the air con.

Let's analyse this, if saving money was a precedent why do we buy a car that devalues by thousands of pounds every year and then try and get pennies back by coasting?

Maybe because they need to travel long distances, need reliable comfortable transport and pay for the fuel as a private individual or self employed 

& you know when you fill a tank fill or 2 a week how it affects your own pocket.

 

Those with Fuel Cards paid by others or just not bothered about consumption and cost might well not give a monkeys.

 

If it is only pennies and it does not slow down your journey them Mony a mickle maks a muckle.

But if it is 40 more miles over a 63 liter tank then that is 500 pennies maybe difference. Price of a double Fried Mars bar supper

or Pizza Crunchie Supper.

Edited 23 December, 20178 yr by AwaoffSki

Facet you have made a good point I didn't think Eco mode would save a great deal of money and I did buy the biggeerdiesel engine for the sake of having a little more power so fuel economy was not foremost in my tbought when I bought the car.