1.2TSI DSG - DSG hesitancy - is this right? - Sulphur Man

All,

We're looking to replace our thirsty 2006 X-Trail 2.5 auto with something more fuel efficient, either MPV or soft-roader.

We went to look at the Skoda Yeti last Saturday - lovely car, although the demonstrator was the 1.8TSI manual, and we're after an auto. So the dealer provided a test drive in a Roomster 1.2TSI DSG, to get a flavour of that engine and transmission, also available in the Yeti.

Our first, and only reaction to the DSG - hesitancy! Pulling up to stationary at a busy roundabout or T-junction, then lightly pushing the accelerator produced at least 1 sec, probably 2 of....nothing. So press a bit more and the car sort of 'woke up' and sprang off the mark. It did this consistently, every time the car was brought to a halt. After both my wife and I had driven it, we decided that if this is the norm, we're not buying a VAG group car with a DSG box.

Querying with the Skoda salesman after handing the keys back, he explained that DSG transmissions 'learn' the driving characteristics of their respective owners, and as this was a demonstrator, it wasnt familiar with anyone's driving style (it had less than 300 miles on the clock).

Is this true? We're both steady drivers (especially when familiarising with a car on a road test). Surely pulling out at junctions or roundabouts in a timely, expected fashion is something an autobox doesnt need to 'learn'? Or is the small petrol turbo engine/DSG setup basically not very good?

1.2TSI DSG - DSG hesitancy - is this right? - RoyWolfey

My 2.0TFSI 05 Golf GTI DSG displayed similar hesitancy charachteristics when going back on to the gas after entering a roundabout.

HJ's Audi A1 car by car review says this in the What's bad section which may shed some light on the issue:

"With DSGs and S tronics, protective software can delay the message from brake switch to ECU that brakes have been released, allowing car to enter a junction or roundabout on the fuel in the combustion chambers, then momentarily shut off mid-junction."

1.2TSI DSG - DSG hesitancy - is this right? - Hacko

Got a 6 year old A3 TDi with dsg - love it ... except for the inevitable (why?) delay on pick up at junctions etc. It really is quite a dangerous feature (fault?) built into the system and if you are a robust driver best not to go for this otherwise fabulous autobox. I won't have another car with dsg, unless VAG find a happy medium between protecting the box and allowing normal get-aways.

Hacko

1.2TSI DSG - DSG hesitancy - is this right? - Sulphur Man

Oh good, not just me then! Our X-trail features a very slushy 4-speed torque convertor box, but at least it responds to the pedal input from stationary without thinking about it.

The mother-in-law's Jazz CVT auto is postiviely sporting off the mark compared to the 1.2TSI DSG!

That said, once on the move the changes and smoothness were impressive. Not impressive enough to excuse the hesitancy though.

1.2TSI DSG - DSG hesitancy - is this right? - mustangman

I can concur what others have said. I have a Golf mk6 1.4 tsi dsg.

In 2 years or so I've never got used to it. The box is very poor at handling the torque reversal from closed throttle to pulling or accelerating. There is almost every time a pause and a jolt as the engine pulls, particularly under about 20 mph.You can mitigate this somewhat by sqeezing the throttle but it never goes away. The box does not "learn" how not to do this.

Its a pity because once at speed the changes are pretty good, in fact better the harder you drive.

I would not have another !

1.2TSI DSG - DSG hesitancy - is this right? - daveyjp

I've never driven a petrol with a DSG, but the diesels I've had and driven as courtesy cars were all excellent. Unfortunately I was driving a courtesy car as my own DSG became hesitant and dangerous - it required a new mechatronic unit - £1500 + labour.

If anyone has a DSG which they think is deteriorating get a drive in an equivalent and see if they are all the same. It was after driving my courtesy car that I realised just how bad mine had become. As my failure took a few months to get really bad I think I adapted my driving to accommodate it.

1.2TSI DSG - DSG hesitancy - is this right? - SteveLee

Buy a Citroën C3 Picasso (the new shape) a far better car in every way then the Yeti - cheaper too.

1.2TSI DSG - DSG hesitancy - is this right? - Vincent de Marco

No autobox available in C3 Picasso, I'm afraid.

1.2TSI DSG - DSG hesitancy - is this right? - SteveLee

No autobox available in C3 Picasso, I'm afraid.

Yet, it's coming.

1.2TSI DSG - DSG hesitancy - is this right? - Vincent de Marco

Yes, maybe, just like in a new C4, a terrible and hopeless 4-speed PSA/Siemens AL4 tranny that simply can't stand 7-speed DSG competition. Wake up, Citroen !

1.2TSI DSG - DSG hesitancy - is this right? - SteveLee

The robotised manual in my Mum's C4 Picasso seems passable - certainly no worse than the described problems above attributed to some of the VAG DSG systems.

1.2TSI DSG - DSG hesitancy - is this right? - Avant

Interesting. I think this could vary according to which engine the DSG is fitted to.

My new Octavia vrs (2.0 petrol with DSG) has none of this hesitation, and I think this is because on slowing down, e.g. going into a roundabout, it changes down through the gears and makes a good attempt at selecting the gear I'm going to need when I accelerate again. This may be an improvement they've made to the latest versions of the gearbox - or it may be that the 2.0 FSI engine has much better torque than many other petrol engines.

I tried a Fabia vRS when they first came out, and there was quite a lot of hesitation, including puling away from rest, although the demonstrator I tried was very new.

1.2TSI DSG - DSG hesitancy - is this right? - mustangman

Just to comment. I've said this before, but the hesitancy mentioned by myself & others is more marked on the 7 speed dsg than the 6 speed.

The difference is that the 7 sp has a pair of single plate dry clutches, whereas the 6 sp has wet multi plates. The 6 sp has the same tendancy but it is much less marked than the 7 sp.

I think since the wet clutches are allowed to slip more this masks the delay & snatch.

We have both in my family, I think 6 sp just about ok, 7 sp poorly developed & vw needs to have a serious look at it. On my 7 sp Golf they would not agree that anything was wrong.

1.2TSI DSG - DSG hesitancy - is this right? - unthrottled

Just to comment. I've said this before, but the hesitancy mentioned by myself & others is more marked on the 7 speed dsg than the 6 speed.

Where was the gaping chasm in the ratios of the 6 speed that required an extra gear? No doubt someone will decide that 7 speeds are inadequate and only the addition of an additional speed will resolve the thorny problem. Oh wait... It's a fair bet that however the manufacturerer sets up an autobox, 50% of drivers will complain that it is too abrupt and unrefined, and the other 50% will complain that it is slurring and lethargic. The correct 'grabbiness' of a clutch set up and the transmission shift point cannot be ascertained by current throttle position/engine speed; it is governed by what is GOING to happen in the near future-which only the driver can determine. Convoluted 'fuzzy logic' cannot compensate for this. If you can't be bothered to operate your own car, you can't complain when the computer doesn't operate it to your liking. If you must use an autobox, pick a nice 5 speed/torque converter and add 10% to the displacement of the engine. A fluid coupling is really the only correct way to operate an autobox-and they lock-up in the higher gears anyway. With hydraulic clutches, governed idle speeds and synchronised reverse gears, manuals are a cinch to drive-even in heavy traffic. The direct-super-macho-mega-turbo robotized transmission is an unhappy marriage of two different technologies. I would stay clear.
1.2TSI DSG - DSG hesitancy - is this right? - Avant

Yes - my Octavia's DSG is 6-speed which may explain things. There is certainly no 'gaping chasm', any more than there was with my previous Octavia, a 6-speed manual, and I agree that there is no need for 7 speeds with this (and perhaps any) gearbox. If instant response is your priority, best to go for a manual.

My memories go back to childhood in the 1950s when 4 speeds (Austin) was a major selling point over 3 (Ford and Vauxhall). Five speeds started to come in about 1970 and six I think about 2000. But there must be a limit - I don't know of a 7-speed manual gearbox.

1.2TSI DSG - DSG hesitancy - is this right? - Vincent de Marco

" If you must use an autobox, pick a nice 5 speed/torque converter "

Easy to say. Let's say I fancy a new Citroen C4 because of its smooth ride. Sorry sir, our 1.6 Petrol 120 HP A/T combination delivers only 4 speed. And yes, it's a classic torque converter thingy.

Trouble is, they've become rare. It's only dual-clutch wherever you go these days.

Edited by Vincent de Marco on 17/04/2011 at 18:21

1.2TSI DSG - DSG hesitancy - is this right? - RT

If you want a modern torque converter automatic, as I did, they usually come with 6-speeds these days and from Korea.

1.2TSI DSG - DSG hesitancy - is this right? - unthrottled

I still opine that 6 speeds combined with a torque converter is superfluous. Unlike a clutch, fluid couplings can 'slip' during gear changes without damage-so fewer ratios are required. Gears shouldn't be seen in the same light as horsepower (ie you can never have too much in reserve). Gears are in constant mesh and each additional one adds bulk, weight and parasitic friction to the drivetrain. Lorries often used to use two transmissions in series ie a 5 speed main and 4 speed auxillary. The trend died a death when turbos widened the engine power band and synchromesh made block shifting easier. 7 and 8 speed transmissions in cars are a marketing fad with no mechanical merit.

1.2TSI DSG - DSG hesitancy - is this right? - brum

IMO

The 7 speed DSG is a dry clutch unit and compared to a wet clutch there is significant clearance when clutches are disengaged. As the clutch for 1st gear is required to slip for smooth takeoff or for slow speed manoeuvring the delay may be the control unit trying to find the bite point before it can proceed with a smooth takeup. During this operation, the ECU will be told to hold off until the box is ready to go. I expect the process of bite location is a bit of a software kludge as I doubt there is a sensor involved, just some feedback from the ECU regarding change of load which is derived and is somewhat delayed. You might find this take up delay increases as clutch number 1 wears.

The other situation, when the box is caught out with the wrong preselection, reveals the true speed in selecting gears in a DSG box - one clutch has to disengage and another engage. There is a significant gap between these two events as any possibility of both clutches being engaged fully or partly would result in a disastrous lockup. Normally this sequence is hidden as its done when the car is accelerating or decelerating and only becomes apparent if the control software made the wrong prediction.

1.2TSI DSG - DSG hesitancy - is this right? - RT

What silly logic! Each extra gear does give more drag - but not nearly as much as the torque converter when it's not locked up. Fewer gears means less time spent in converter lock-up.

Torque converter plus 6 gears works well for me - top gear is high enough to run at 2,000 rpm at 70 mph, bottom gear is low enough to get 4.5 tonnes away from a standing start quickly when towing and there's no gaps in between.

I've driven enough cars with noticeable gaps in the ratios over the years to know that they're a PITA.

1.2TSI DSG - DSG hesitancy - is this right? - unthrottled

Fewer gears means less time spent in converter lock-up

Not true! Fewer gears means fewer redundant shifts-the torque converter isn't locked whilst it is shifting or it thinks a shift is imminent. Although, with a gross vehicle mass of up to 4.5 tonnes, a relatively close ratio box is very useful. But for your average Joe driving along with nearly 100hp/tonne, agonising over whether the engine should be at 2150RPM or 1900 RPM is silly. But for hauling, I think your choice of slushbox makes more sense than the DSG robotized thingy.

Edited by unthrottled on 18/04/2011 at 14:41

1.2TSI DSG - DSG hesitancy - is this right? - Avant

So if by all accounts the 6-speed DSG works fine, why did VAG go to the trouble of developing a 7-speed unit which works less well? Anyone know?

1.2TSI DSG - DSG hesitancy - is this right? - unthrottled

When Lexus introduced the 8 speed, 6 looked distinctly ordinary.

Same goes with the number of valves. VW flirted with a 5 valve/cylinder engine -didn't flow better than a conventional 4-but it gave them a marketing edge.