vRS TDi DSG not engaging back in gear in Eco mode after coasting!

[andyvee]

Problem is I think the designers over at VAG have come up with this as a way of increasing fuel economy and decreasing emissions in the official tests without considering real world driving where coasting for long periods is not really possible unless you have long stretches of level or slightly downhill road. Coasting in the UK is usually coming up to traffic lights/junction where you coast for a bit then use the breaks, so no benefit here, or coasting down hills where this new feature will allow the car to run away and you will need to be on the break all the way down = more fuel used and you have break fade at the bottom when you need to stop.

 

Probably works great on a rolling road but around town or on A/B roads (And probably most UK motorways) I'll remain a sceptic for now.

 

As soon as you touch the brakes it reengages the gears for engine braking, so you won't suffer excessive brake fade and neither will the car run away from you or use more fuel.

[Anddenton]

Yeah curious to hear an IAM instructors thoughts on it.

 

 

But in the Hybrid you can use regenrative braking which drives the motor as a generator to pump power back to the batteries. This produces drag similar to engine braking.

 

In normal 'D' mode the Yaris hybrid didn't do this and just coasted with engine off and motor not engaged.

 

Phil

 

Point is though the engine is cut so no fuel is used - in the Octy fuel will be used to maintain the engine at idle.

 

As soon as you touch the brakes it reengages the gears for engine braking, so you won't suffer excessive brake fade and neither will the car run away from you or use more fuel.

 

Good point, I had missed that fact.

[Phil-E]

Point is though the engine is cut so no fuel is used - in the Octy fuel will be used to maintain the engine at idle.

 

 

Good point, I had missed that fact.

 

Ah yeah. I get ya.

 

I'm sure some maths type person in VAG has calculated very acurately that you still save fuel as apposed to coasting in gear.

 

Phil

[Anddenton]

Ah yeah. I get ya.

 

I'm sure some maths type person in VAG has calculated very acurately that you still save fuel as apposed to coasting in gear.

 

Phil

 

Yes, but probably only for the official economy test, not for real world driving!

[Sheldon.Cooper]

For guys who already have their cars, can you select Eco from the mode button but have the coasting function disabled from the options? So if you want it, you can still use Eco but without the fiddly bit which is coasting?

No.

 

The only difference between Eco and normal is coasting (plus a minor air con tweek).  So if you want Eco without coasting then select Normal. 

[rwbaldwin]

My guess is OP is thinking coasting is the same as with a manual box and put the car in Neutral.

The car must remain in Drive for the DSG box to coast. This is by design so it is controlled coasting - the DSG can re-engage at any time. It goes from coasting to engaged as soon as you touch the brakes so the forward motion is used to turn the engine (fuel cutoff).

[bouff34]

No.

 

The only difference between Eco and normal is coasting (plus a minor air con tweek).  So if you want Eco without coasting then select Normal. 

And if you use the individual profile you could adjust the aircon to low setting so that you effectively have ECO but without coasting...

[Dempsek]

Is this just an issue with the 6 speed DSG?

 

From the manual.

 

ECO mode

 

Engine (drive)

The accelerator pedal is less responsive to depressing the pedal, and the acceleration

is more relaxed than in mode Normal.

After pressing the button, the acceleration occurs more relaxed than in mode

Normal

 

» page 141, Cruise Control System.

The recommended gear is controlled such to achieve the lowest possible fuel

consumption

 

» page 26.

When the START-STOP system was deactivated manually

 

» page 153, it is automatically

activated.

The automatic gearbox is set automatically to mode

 

E » page 121.

Adaptive headlights (AHL)

The system is automatically deactivated

 

» page 54.

Air conditioning (Climatronic)

The air conditioning is controlled so as to save energy. For this reason, for example,

it may take longer to reach the desired interior temperature in mode Normal.

[andyvee]

No.

 

The only difference between Eco and normal is coasting (plus a minor air con tweek).  So if you want Eco without coasting then select Normal. 

 

????

 

It changes gear earlier, the throttle is less responsive - whole host of differences

[philbes]

Coasting with the car in neutral would be an instant fail on the IAM Advanced Driving test.  Indeed I know of a candidate that failed within 5 minutes of starting the test because he depressed the clutch to roll over each of a series of speed bumps.  I am meeting an IAM examiner at a training course tomorrow and will discuss this with him.

Meet the IAM test examiner yesterday (Saturday).  He confirmed that coasting with neutral engaged on a manual gearbox car would be an instant fail.  However, if it is a in-built function of a car with an auto gearbox to select neutral and coast he would reluctantly have to accept this.  If the car then failed to re-engage a gear when necessary (as occurred with a couple of posters) then the car would be considered un-roadworthy and the test terminated. 

[IainC]

A marginally relevant historical note: in 1970 (I think) my father bought one of the first Saab 99s in the UK.  It was a manual gearbox on a petrol engine but it had a Freewheel Function (inherited from the Saab 96).  This meant that taking your foot off the accelerator pedal would immediately put the car into neutral mode (so that the car would coast), and it also allowed the driver to pre-select a new gear without depressing the clutch.  The engine re-engaged when the accelerator was pressed again.  There were no fancy electronics to enable or disable the function - it was just how the engine/transmission was designed.  It was in my very early years of driving, and it seemed like quite a relaxed method, but it did require some anticipation.  I recall pre-selecting third gear while coasting/braking into a corner, then accelerating out of the bend, all without troubling my left foot.  It also did improve fuel consumption: my father reckoned he could get around 40mpg on his 30 mile daily commute.  I don't remember him mentioning downhill braking problems, and it was quite a heavy car for its time.  I assume it was legal, although the replacement model (with a larger engine) dispensed with the freewheel.  I think that Saab's sales line was that the freewheel made the car safer in the ice & snow of Sweden.  Probably of marginal benefit in Fife.

[Rabolt]

Thanks for all your replies so far! An update on a round trip of over 400 miles on mostly motorways. I tend to take it easy for the first 10000miles and I have now reached 1080miles. I have found that in Eco mode, if you let the road speed drop below 40mph and you put your foot back on the gas, then the gear box still tries to run in 6th gear and then that is when the engine seems to bog down. This happend a couple of times as I coasted from 70mph to slow down due to slow moving traffic. I do not use the break if I do not need to! Unnecessary use of the breaks can cause traffic hold ups! That's for another topic! I do intend to talk to the dealer about this. Now I am back from my hols. On another note, I had an augment with my daughter's driving instructor, a couple of years ago when she was learning to drive because I was teaching her to change down on approach to traffic lights and stand stills. She was told by her instructor to COAST to a stand still and that is what the examiner would want to see. Apparently it is cheaper to change break pads than a gear box! And it saves fuel!

Bristol to Hull - 57mpg average over first 1000miles - 47mpg Looking forward to using the vRS as intended but I chose the diesel to have the best of the both world's. You can't drive like a hooligan all the time!

[Rabolt]

Thanks for all the in-depth replies. I took the car back to the dealer after the car stalled in eco mode approaching a roundabout! It stayed with the dealer for the day and they could not find a fault. They did a software update and also tried to activate the cornering fog lights. No look. Took the car back and they have reported to Skoda. They said the had a couple of DSG cars just in and they would try them in Eco.They rang me to tell me that they had the same problem and they have filed the fault with Skoda. In the mean time Do not use Eco!

I will keep you posted.

[Dempsek]

Thanks for the update, I do not seem to have the problem with my little 1.4 and the 7 speed dry clutch DSG.

[henderson]

Can someone please explain to me how an engine can run without fuel ? I went to school and got an A in chemistry but still cannot fathom how an engine runs without fuel !!!! it defies logic which by the cut of peoples Jab I conclude that members on here have a much higher IQ than 210.

 

Just my opinion

[henderson]

so getting back to topic who is having the problems that the OP has described I don't own a vrs But I am awaiting delivery of a Dsg  car which is why I want to know about these problems, rather than a nonsensical debate on issues that need to be I a new feed/topic. WE learn something  new everyday but we also waste our lifes reading through meaning less garbage that could really have its own place   

[Sheldon.Cooper]

I've had a serious issue where slowing down for a roundabout (coasting), then when I tried to accelerate (doing ~20mph) the gearbox kept selecting 2nd then 3rd then 2nd.  All the time it just revved with no forward motion.  The gap I was accelerating into rapidly disappeared and I almost got hit due to no drive.  After hitting the brakes (ffs people, learn the difference between breaks and brakes) I had normal drive again.

[sworrall]

so getting back to topic who is having the problems that the OP has described

me

[TudorM]

Can someone please explain to me how an engine can run without fuel ? I went to school and got an A in chemistry but still cannot fathom how an engine runs without fuel !!!! it defies logic which by the cut of peoples Jab I conclude that members on here have a much higher IQ than 210.

 

Just my opinion

 

The reverse of normal operation happens. The wheels turn from the forward motion of the car, which in turn turns (get it? ) the gears inside the gearbox, then the flywheel and so on until turning the crankshaft which keeps the pistons in motion. So with modern fuel injected engines, no fuel is needed when that happens. Hopefully that clears it up.

 

Of course, you'll have to be in gear for that to work. If you're in neutral, fuel will be injected to keep the engine on idle.

 

I've had a serious issue where slowing down for a roundabout (coasting), then when I tried to accelerate (doing ~20mph) the gearbox kept selecting 2nd then 3rd then 2nd.  All the time it just revved with no forward motion.  The gap I was accelerating into rapidly disappeared and I almost got hit due to no drive.  After hitting the brakes (ffs people, learn the difference between breaks and brakes) I had normal drive again.

 

The manual states that the DSG will re-engage a gear after depressing the braking pedal, not the accelerator. I know it's odd and counterintuitive, but it did work as intended.

Edited 17 December, 2013 by TudorM

[Sheldon.Cooper]

 

 

The manual states that the DSG will re-engage a gear after depressing the braking pedal, not the accelerator. I know it's odd and counterintuitive, but it did work as intended.

So the intention after coasting is to not allow acceleration until you brake?

 

Marvellous intention that..... absolutely marvellous

 

If you take your foot off the accelerator then you need to brake before you can put in back on the accelerator again???????  behave, the manual states the DSG will re-engage a gear after depressing the brake pedal or accelerator.

 

I am very thankful I hate Eco mode and won't ever use it again.

Edited 17 December, 2013 by Sheldon.Cooper

[TudorM]

Like I said, not the most intuitive way of doing things, but that's what you get... I just think ECO will not bring that much extra economy, so I'm not using it anyway.

[sworrall]

The reverse of normal operation happens. The wheels turn from the forward motion of the car, which in turn turns (get it? ) the gears inside the gearbox, then the flywheel and so on until turning the crankshaft which keeps the pistons in motion. So with modern fuel injected engines, no fuel is needed when that happens. Hopefully that clears it up.

Of course, you'll have to be in gear for that to work. If you're in neutral, fuel will be injected to keep the engine on idle.

The manual states that the DSG will re-engage a gear after depressing the braking pedal, not the accelerator. I know it's odd and counterintuitive, but it did work as intended.

i think that is probably a typo as mine re-engages from the accelerator 95% of the time. Just not that odd time around 45mph.

Os. Where I live there are lots of hills and when it coasts the average mpg flys up so it is more efficient for me from the gauges.

But hell. I'm in individual sport most if the time anyway

[Dodgy]

me

 

Me too.

[sworrall]

Me too.

its arrived?? 

[Dodgy]

its arrived?? 

 

Yeah, picked it up on Thursday evening. Apart from this particular issue, everything is great! Love the electric door lift!