Dual Clutch Transmissions: Pros and Cons

Описание: 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.