Dual Clutch Transmissions: Pros and Cons

1) Intro and housekeeping:
This is going to be a fairly in-depth video on gearboxes, so I suggest not watching if you don’t appreciate a certain level of geekery!
First of all, I’d like to say a few disclaimers: the test car in question is a 2011 VW Golf 2.0 TDI with the optional 6-speed DSG3. I have driven other DSGs from the likes of Ford and Audi (7- speed) so therefore can bring a rounded and authoritative opinion.
A dual-clutch is not an automatic gearbox as most dealerships and salesmen will state, this is a simplification of terms to drive sales to uneducated consumers. It is in fact an automated manual gearbox, where the car’s ECU controls the clutch(es). There is one clutch for even gears, and one clutch for odd gears allowing the car to preselect, what it thinks, is the most appropriate upcoming gear.
They were manufactured in order to bring automatism of gear-changing, without the drawbacks of traditional torque-converter automatics of the time. These drawbacks comprised inefficiency, slow changes and blunted performance due to partially unlocked torque converters (equivalent to a slipping clutch). The first time I personally learnt about DSGs was Top Gear’s review of the Audi TT 3.2 Quattro - Clarkson praised its quick shifts and responsive manual override.
We are now going to see the benefits and drawbacks of the DSG.
2) Benefits:
- Smooth shifts;
- Efficiency: explain it hits 5th at 30 MPH and 6th at 40 MPH;
- Shifts are way quicker than a human could achieve with a manual transmission;
- Responsive override. Our car sadly isn’t fitted with paddle shift but the tiptronic function works
well.
- Intelligent mode works well: this car is owned by Grandfather who drives like, well, a grandfather. When I jump into the seat, which is usually of an interval of 2-3 months, it only takes a couple of trips for the transmission to adapt to my more aggressive and youthful driving style.

3) Drawbacks/criticisms:
- Too much difference between Drive and Sport modes. I understand that a 2.0 TDI is meant to be efficiency orientated, but upshifting at 1800 RPM is ridiculous and blunts the driving experience. Also, it’s ironic to say VW is motivated by economy and efficiency - #DIESELGATE. Sport mode on the other hand holds gears too long, keeping the revs at the top end of the rev-range. This would be ideal in a petrol, but not so for a diesel which produces all of its power at the bottom of the rev-range.
- One must upshift 500 RPM before redline in order to achieve best acceleration, as the gearbox bogs.
- Although generally responsive, the gearbox can sometimes be laggy. Because of its short shifting tendencies, if you spot a gap in trafic and wish to accelerate briskly, you must wait for the box to downshift. If the box held gears a little longer in D, it would offer constant torque accessibility. Kick-down is equally slow to respond, meaning use of tiptronic is much better for overtaking. A final point regarding lack is at junctions, there is sometimes a bit of between depressing the accelerator and moving away; this can cause the driver to panic and therefore overcompensate, making for an overly aggressive take-off.
- The ECU and its software can be caught off guard. As mentioned previously, the transmission has one clutch for odd gears, and one clutch for even gears. It predicts which gear to pre-select by judging drivers’ tendencies. E.g you’re in third and gradually accelerating, the gearbox will pre-select 4th. This is fine in 90% of situations. However, if you’re in third and gradually accelerating, then hit kick-down, it will have to move the clutch from pre-selecting 4th to actually selecting 2nd - this does take a bit of time.
- ! At slow speeds on inclines, e.g a steep carpark, this gearbox is simply dangerous. Being an automated manual, the ECU decides when to engage and disengage the clutch. When reversing, uphill, out of a parking bay, the gearbox is slipping and engaging the clutch constantly meaning it’s very, very jerky. In extreme circumstances, one is forced to left-foot brake in order to control the car safely. !
- The engine braking down hills is absurd. If you’re driving down a hill, the transmission will downshift holding the revs at over 3000 RPM - this kills the economy and the NVH levels!
- Reliability has proven to be somewhat of an issue on early VAG cars, the Mk. V GTI is known for its transmission related troubles.

4) Conclusions:
I feel, that DSGs have had their time, and have now become obsolete due to the forced innovations of traditional torque-converter automatics. DSGs forced torque-converter autos to be more competitive, by way of increased efficiency, quicker shifts and greater reliability. A case in point is the universally heralded ZF 8-speed, utilised by multiple manufacturers for its compromise of performance and reliability.

[ajaysingla]

A very good review of DCT. Just to add if I may two other drawbacks of DCT from my experience. 1. the gearbox tends to hestitate at roundabouts and junctions and does not like to be hurried. Its not very good for quick smooth takeoffs and the car can wheelspin at times. 2. The car tends to jerk in the 1st gear providing very uncomfortable driving experience. In my opinion DCT is not suited for regular city and town driving which is why I rate torque convertors very high as they provide the best allround experience and there is no match to it for refinement and smooth gear changes. Modern torque convertors are brilliant in that there are so fuel efficient like the one in my Vitara. Of course DCT experience will vary in different cars but from my experience it has its limitations in town and city driving and you can't use creep function like you do with torque convertor gearbox as it will wear out the clutch plates and can cause expensive repair work.

[jbones]

You say Diesel DSGs aren't as good for performance than petrol. My 10 year old Audi A3 DSG 2.0 TDI is insanely fast, the diesel gets incredible grip and acceleration that I've never come close to feeling in a car before. It puts my old beloved MK4 Golf Cabrio to shame.

[Michael_Schm]

The ZFs are also in almost all BMWs with 8-speed automatics. Different models of it ofcourse.

[MegaBandit]

Could not be happier with the DSG in my Renault. Matches well with 1.3 petrol eng.

[nickbianchi]

I stopped when you stated that dual clutch might become obsolete :D
Take your automatic gearbox to the Swiss mountains or elsewhere in the Alps and experience by yourself how terrible this type of transmission can be to drive!

[eros]

285000 Miles. Same Dual Clutch transmission. No issues. 2007 a3. I had a torque converter auto from a 2000 VW (Aisin). Failed at 175k

[JB-NZ]

Would love to know your comments on a DSG, reversing, up a hill.... How do you find it. To me, its like a teenager learning to drive, slipping the clutch, over revving. I have a 09 Passat R36, and reversing up a hill is horrible, but apparently quite normal to be horrible. Have you experienced this, and are the later models of the DSG's similar? I guess its not that common for most people to ever need to reverse up a hill, so maybe most people would never have experienced it. Let me know!

[johnbower]

Have to say my old Mondeo had a Torque converter and she was smooth as silk and pretty quick too.

[RogerThomas-wsmd]

Very informative video thanks, I am about to take ownership of a 2.0 auto DSG Diesel
VW CC from 2008 so will be interesting to see how it handles everyday driving.I would likely be able to do a bit of Intervention if acceleration is required all of a sudden I would expect?

[yoong]

As you say that a DCT is a automatic operated manual box, is it actually we are encourage or drive more using the tiptronic or manual mode? As people also say that excessive usage of tiptronic or manual mode can cause problems to the box.

[adoreslaurel]

Can you imagine being in a mile long queue when road works are being carried out, two lanes converging into one, now normally we try to be polite and allow ever second car to encroach on "our" lane, 'cause we are in the "correct lane", but
since you have a dual clutch trans and you are advised not to "creep' 'cause that aint good, riding the clutch to crawl forward, so what happens? you leave a big space so that you can move up without too much slippage, but guess what! every time you do it, somebody next door says gee thanks and fills "your spot", no need to say that nobody in your lanes moves forward but everyone in the other lane slots in and everyone behind you has a desire to "kill you".

[slightlyjaded]

The problem of entering into any experiment with your conclusion already worked into your hypothesis is you will always find a conclusion to support your theory.

[bmuns]

How long does a DSG last? I dumped my Acura after 2nd failing rebuilt trans. I have 2014 VW GLI. I don’t beat on it, don’t race it, very conservative. But do have Unitronic stage 1 engine and transmission tune. 170k miles.

[keithharley]

It's not so much the clutch or the gearbox. It's more the dual mass flywheel. They are not as strong as they should be. I've had 2 failures and it always toasts the clutch.

[RigiLiquid]

It's brilliant in the Kia Niro hybrid. In sport mode it's quick off the line.

[comedyman]

What year were the "newer" torque converter gearboxes used in? Past 2010? Or are you talking past 2015?

[dwightbaldwin]

Sorry if it's been addressed....but can you leave it on automatic 24-7 and not damage trans....I know I'd be losing fun factor but I care most about least amount of maintenance

[natecaraway]

Modern automatics definitely have come a long way my dad's Mk7 has a traditional automatic and it's as smooth and almost as quick as the DCT in my Mk5 Jetta

[shawng]

I have the Ford Focus equivalent and it is very lumpy to drive low down. I catch it out on approaching a roundabouts all the time or I used to. When approaching a roundabout you are usually going down the gears but if there is a gap and you want to accelerate into it you catch it by surprise and it has to think for a second or two before going back up the gears. I now slap it across into sport at junctions and roundabouts just because it is smoother and quicker. Sometimes I can put it into reverse and it will be a good 5 seconds before It selects it. I have a diagnostic computer and it even comes up there as a fault on the reverse gear. :(

[angus]

So if it’s not auto then why do the gear change without you changing them? That’s what automatic means