DQ381 coasting

[nicknorman]

One thing I have noticed with  my new car (7 spd DQ381 box) is that even in Normal drive mode, the gearbox sometimes goes into coasting  mode. Only happens in the higher gears and only when the throttle is gradually reduced. If you lift off quickly, the drive remains engaged. I am not too keen on this to be honest, is there a way to turn it off (other than going to Sport or Manual?)

[Ootohere]

Sorry no idea.

 

What is wrong with it disengaging from Drive when there is no load on the engine and the light throttle or no throttle touched does not require drive to keep rolling along and there being no engine braking?

Just touch the accelerator with a bit of a press and it is back in D6 or D7, or D what ever gear.

[nicknorman]

19 minutes ago, Rooted said:

Sorry no idea.

 

What is wrong with it disengaging from Drive when there is no load on the engine and the light throttle or no throttle touched does not require drive to keep rolling along and there being no engine braking?

Just touch the accelerator with a bit of a press and it is back in D6 or D7, or D what ever gear.

It’s not a huge deal but I would prefer to be able to turn it off. Most of my driving is rural Scotland with lots of ups and downs and I am accustomed to the engine braking. What happens at the moment is that I crest a hill, reduce throttle, it starts to coast, I then press lightly on the brake to reduce speed and the clutch engages again. It would be simpler if the clutch didn’t disengage in the first place and over time it must increase wear a bit.

 

Coasting only save fuel if you don’t want the car to slow down - in coasting mode the engine is using fuel to maintain idle, on the overrun the fuel flow is zero.

 

Centuries ago I did have a Saab 96 v4 with a freewheel, I quite liked that but that was a different beast of a car.

[Ootohere]

You maybe need to look again at COASTING mode these days and using fuel.  Because you are wrong.

We are in a different era, and the DSG & Coasting is for WLTP / RDE2 and does reduce fuel. 

 

& It is not wearing out anything, not even the brakes if you do not use them.

Great driving roads.   SEmi Automatics / DSG, there is a shifter and paddles. 

 

That why i love it over Cairn o Mount on to Grantown on Spay & the A93.

Makes a big difference fuel wise coasting and then just a push of the accelerator on bends, or manual down shifts. 

 

I did the Trip Forfar to Nairn via Edzell, Fettercairn, Ballater, Tomintoul & Grantown on spey, (Return to Braemar and then south better coasting.) near weekly over 3 years in Alhambra 2.0 TDI SCR and the difference from the 63 litre tank could be 630-660 miles not coasting enabled and over 700 miles with.

Same speed a journey time and not hanging about.

 

Now doing it in EV,s they are always coasting & regening otherwise not that efficient.

Edited 11 December, 2023 by Rooted

[nicknorman]

32 minutes ago, Rooted said:

You maybe need to look again at COASTING mode these days and using fuel.  Because you are wrong.

We are in a different era, and the DSG & Coasting is for WLTP / RDE2 and does reduce fuel. 

 

& It is not wearing out anything, not even the brakes if you do not use them.

Great driving roads.   SEmi Automatics / DSG, there is a shifter and paddles. 

 

That why i love it over Cairn o Mount on to Grantown on Spay & the A93.

Makes a big difference fuel wise coasting and then just a push of the accelerator on bends, or manual down shifts. 

 

I did the Trip Forfar to Nairn via Edzell, Fettercairn, Ballater, Tomintoul & Grantown on spey, (Return to Braemar and then south better coasting.) near weekly over 3 years in Alhambra 2.0 TDI SCR and the difference from the 63 litre tank could be 630-660 miles not coasting enabled and over 700 miles with.

Same speed a journey time and not hanging about.

 

Now doing it in EV,s they are always coasting & regening otherwise not that efficient.

 

It can certainly reduce fuel consumption under certain conditions and it certainly did on the Saab 96. But under certain conditions it doesn't because as I said, the engine is being fuelled to keep it at idle and that is only any use if the car doesn't end up going a bit too fast so you need to apply the brakes. Put simply, scenario 1 you descend a hill without freewheel, the speed is about right, no fuel used. Scenario 2 you descend same hill with freewheel, after a while the speed is a little on the high side of right so you press the brakes and return the speed to that of scenario 1. Except that in the mean time the engine has been using a bit of fuel to keep it idling.

 

Anyway I have found the answer to my question elsewhere on the forum, it looks like the freewheel function can  be disabled in vcds. So once the dust has settled on my new car and if I still don't like it, I can disable it.

[Ootohere]

I only have one foot (Left foot using standard throttle pedal.) and driven Automatics since 17 years old and before 'Coasting mode' was introduced knew how to drive quickly and efficiently.

I started driving DSG,s over 13 years ago.

If you think the fuel used to keep the engine running with the Clutches disengaged with a DSG is as much as being in gear then so be it.

DSG,s are OK for downshifting and it was Mk2 vRS DSG,s with Twinchargers & DQ200,s i drove. No Coasting but still toe off the accelerator. 

 

Touch the accelerator without gaining speed and go back into gear, or drop a gear because there is engine breaking.

Winter, snow, ice i virtually never touch the brake pedal unless stopping. 

 

Each to their own i suppose. 

 

@lol-lolputs DSG,s in N which is something i never do ever when moving / descending.

Edited 11 December, 2023 by Rooted

[lol-lol]

43 minutes ago, Rooted said:

I only have one foot (Left foot using standard throttle pedal.) and driven Automatics since 17 years old and before 'Coasting mode' was introduced knew how to drive quickly and efficiently.

I started driving DSG,s over 13 years ago.

If you think the fuel used to keep the engine running with the Clutches disengaged with a DSG is as much as being in gear then so be it.

DSG,s are OK for downshifting and it was Mk2 vRS DSG,s with Twinchargers & DQ200,s i drove. No Coasting but still toe off the accelerator. 

 

Touch the accelerator without gaining speed and go back into gear, or drop a gear because there is engine breaking.

Winter, snow, ice i virtually never touch the brake pedal unless stopping. 

 

Each to their own i suppose. 

 

@lol-lolputs DSG,s in N which is something i never do ever when moving / descending.

 

Yes guilty as charged, twin charged.

 

Never a problem doing so.  Did about 70k in my Fabia 2 VRS.  Best tankful was 630 miles, mind you could get 50 litres in the tank by supressing the little black button in the filler neck.

 

Later cars, the mark 2 Oct with the 7 speed DSG, a lovely L&K 1.8 TSI, OMG< better than the VRSs in my opinion, short stroke EA888 engine revving to 7k revs, 0-60 in a nidge over 7 seconds, 160 hp the hell it was, way quicker than the wiesel VRS.  Any road up that would it was either than one or probably the 1.4 TSI with the 7 speed DSG would open both dry clutches and drop the engine revs to zero, effectively coast the car, touch the brake or accelerator and the car would nigh instantly put itself in gear, great fuel saver, well in to the 50s mpg.

 

Now the similar 7 speed EDC Renault box in the Arkana does the same, setup coasting in the menus and revs drop to zero when no load, batteries, not sure if it is the 12v lead acid or 12v hybrid battery maintains lights, electric power steering and fuel consumption benefits big time.  In the summer well into the 60s mpg with the 1.333 litre Mercedes/Nissan/Renault engine almost instantly ready to reapply power when pedals touched, great system.  These cars need heat pumps, like my Zoe has, to work better in cold weather as these mild hybrid, as well as the fully hybrids are great with fuel during warm weather but not so great in cold weather.

 

No so great freewheeling/coating in a manual but seems fine in semi and full autos I have had, even coasting in the Zoe quite often ie stick it in neutral rather than using regen. keeping within the speed limits of course.  

 

[komoornik]

 

[Kenny R]

3 hours ago, nicknorman said:

It’s not a huge deal but I would prefer to be able to turn it off. Most of my driving is rural Scotland with lots of ups and downs and I am accustomed to the engine braking. What happens at the moment is that I crest a hill, reduce throttle, it starts to coast, I then press lightly on the brake to reduce speed and the clutch engages again. It would be simpler if the clutch didn’t disengage in the first place and over time it must increase wear a bit.

 

I like the coasting, but in rural up down twisty roads I just pull the gear selector back into sport mode and no coasting and engine braking when lifting off as required. 

[KeteCantek]

5 hours ago, nicknorman said:

One thing I have noticed with  my new car (7 spd DQ381 box) is that even in Normal drive mode, the gearbox sometimes goes into coasting  mode. Only happens in the higher gears and only when the throttle is gradually reduced. If you lift off quickly, the drive remains engaged. I am not too keen on this to be honest, is there a way to turn it off (other than going to Sport or Manual?)

There should be no coasting in normal mode? Unless something has changed on newer cars. 

 

Is it actually just shifting up to the highest gear instead? 

 

 

[Kenny R]

3 minutes ago, KeteCantek said:

There should be no coasting in normal mode? Unless something has changed on newer cars. 

 

Is it actually just shifting up to the highest gear instead? 

 

 

My Kodiaq with the DQ 381 dsg is exactly as described by the OP, in that coasting occurs in normal and eco mode, putting the dsg into sport mode it doesn’t coast.

My previous Kodiaq with the DQ500 dsg only coasted in eco mode.

[MartiniB]

8 minutes ago, KeteCantek said:

There should be no coasting in normal mode? Unless something has changed on newer cars. 

2016. Mk3 had coasting only in E

2023. Mk3.FL by default also in D, but it can be coded out

-> https://www.briskoda.net/forums/topic/516414-vcds-options-on-superb-iiifl/

 

i prefer to have all 3 modes under hand, just by single move of gear stick -

1. D without coasting, lite braking by engine

2. move forward to N for coasting

3. move backward to S for harder braking by engine or quicker starting from standstill

 

Edited 11 December, 2023 by MartiniB

[KeteCantek]

12 minutes ago, Kenny R said:

My Kodiaq with the DQ 381 dsg is exactly as described by the OP, in that coasting occurs in normal and eco mode, putting the dsg into sport mode it doesn’t coast.

My previous Kodiaq with the DQ500 dsg only coasted in eco mode.

Ah so they changed the logic. I'd be annoyed with coasting in normal mode I think. Simply because there is a slight delay for gear to engage when getting back on. 

 

Absolutely fine in eco when I am in the mood for it though. 

[Berisford]

I've got a 280 and never ever seen 'coasting'.........

[nicknorman]

2 hours ago, Berisford said:

I've got a 280 and never ever seen 'coasting'.........

I think it only started after "Facelift". Certainly my just-traded-in 2016 model only coasted in Eco.

[nicknorman]

2 hours ago, KeteCantek said:

There should be no coasting in normal mode? Unless something has changed on newer cars. 

 

Is it actually just shifting up to the highest gear instead? 

 

 

 

Yes it has changed on newer cars. Definitely coasting. D7, D6 or whatever changes to D and rpm drops to idle.

[numskull]

I’ve found the amount of engine braking in D to be negligible. It’s a bit better in S but still not that effective. 

[Gabbo]

13 hours ago, nicknorman said:

 

Yes it has changed on newer cars. Definitely coasting. D7, D6 or whatever changes to D and rpm drops to idle.

 

I have noticed the same on my car.

If you have the flappy paddle shifters you can just press the down shift paddle once & it will engage the gear again without moving into "manual" mode.

 

If you have no accelerator pedal input, the engine is not using any fuel if the gear is engaged so this is always better than coasting in my opinion & engine braking can prevent unnecessary braking which has a knock on effect on traffic flow of you drive in a way to anticipate the traffic ahead.

 

Whether coasting versus engine braking really gives a fuel economy benefit will obviously depend on the road conditions or gradient.

However as all automatic gearboxes I have driven recently seem to do this (Volvo, Mercedes, Skoda) there must be some logic/science behind it.

 

[Ootohere]

Traffic flow and in traffic is very different from knocking on on great driving roads.

In that traffic and dual carriageways or motorways or even single carriageways then using ACC might come into the equation. 

 

@Gabboif off the accelerator and in D or S or M1,2, 2 etc uses no fuel then WTF did they bother introducing 'Coasting mode'.

Was it just for testing under WLTP or RDE2 Conditions?

 

**Probably to have the gas guzzlers look like they are quite efficient and have low Co2 k/km and be able to sell them and still meet Average Fleet Emissions in the EU and the same in the UK.**

 

AUDI / VW even had a Defeat Device with 3.0 litre engines with DSG,s to cheat under testing and were fined for that.

 

The future as VW are forced to for causing all the emissions crap and cheating is when not full BEV, ot PHEV, is Mild Hybrid, the ACT / COD but with less polluting ones & coasting.  & Sat Nav / GPS knowing the road and switching off when the ICE not requit=red.

Edited 12 December, 2023 by Rooted

[nicknorman]

It is interesting that when ACC is engaged, there is no coasting in D.

[MarkyG82]

@Rooted The argument for either camp has been discussed many times and every time it becomes clear that it depends on the circumstances. 

It's a fact that when you lift the go pedal while in gear the engine uses no fuel.  However, there is still some loss as the engine is being turned over so the car will slow and you then need to use fuel to get back to speed.  Coasting out of gear with the engine running will use fuel to turn the engine over but the car will roll more freely so it's down to the use case as to whether it's more efficient or not. 

Where you cannot argue the efficiency gain is with any hybrid (HEV, PHEV or MHEV) where the engine cuts out when coasting. 

The cars we are discussing here are none of those so lets leave the discussion there and think about the original point of driving modes.  It seem that the factory changes the activity of the boxes at different times.  Is there a link to release date and the functions described?

[Ootohere]

Next generation models or Euro 7 compliant will need the bits and pieces of tech that VW Group have been using the paying customers to do the R&D over the past decade.

Many models from the 4 brands at the price level of Skoda have some features and some of VW Groups cars have all of them. 

[Dieselgate]

Coasting definitely has benefits in the right conditions. We have a nice long and fairly steep hill on the motorway near us where if you take your foot of the accelerator at 65mph at the top you can sometimes be doing 78+ at the bottom. Needless to say you wouldn't have that if you left it in gear.

[nicknorman]

Well anyway, I have now turned it off. It does also turn off coasting in Eco which is perhaps not ideal, but then I never use Eco!

[Gabbo]

On 13/12/2023 at 12:17, nicknorman said:

Well anyway, I have now turned it off. It does also turn off coasting in Eco which is perhaps not ideal, but then I never use Eco!

Did you turn it off with VCDS/OBD11?

I've just seen this thread & after a few months trying to get used to the DSG I think I'll do the same. I feel like I'm constantly flicking the paddle to put back the gear or braking unnecessarily when I'm accelerating above the speed limit or towards the car in front.