[no1_jazz]

Good Evening all.

I wanted to ask you all if you could share your opinions on the following questions I have:

Q1: Which would be cheaper to maintain?

Q2: Is there a noticeable difference in the performance between the two transmissions? I.E Straight line acceleration?

Q3: Could you please explain the pros and cons between the two?

Q4: To those of you who own a DCT… Do you ever miss slamming and crunching her into gear?

Having always driven a traditional manual for most of my driving years, I must say I am very comfortable with it. I feel very much connected with the car and under control.

I am totally new to the DCT world and would like to know a little more about it.

Regards
Jazz

[oliver51090]

Can't answer all them questions but what i will say is this. Its a joke driving auto. So easy traffic is a breeze. But i would never get another auto unless it was a high performance car. I miss clutch control and slotting the gear stick in place. Auto's are definitely faster these days though!

[ndj]

1. Don't know specifically but from a reliability standpoint there are no recurring horror stories with BMW's DCT box.

2. Yes, DCT gear changes are always going to be quicker than human meaning drive is almost continuous. Also, a DCT box has 7 ratios.

3. Cons? You need to try it and make up your own mind.

4. Absolutely not. Would never go back to a manual.

[djgandy]

I own a Manual but have driven a few DCT's. The DCT box is really very good. The gear changes are extremely quick and smooth. The sound of the changes is nice, but you loose some of the garglyness from the exhaust that you get from the MT I thought.

The DCT is very odd at low speeds, because it is just an automatic manual if you like and you have to treat it like that when parking etc. You get used to it, but it isn't like an old fashioned auto where you have engine force always fighting against braking force until the point you are off the brakes. There is kind of this second guessing game going on when you first drive one where you and the box aren't quite on the same page. You get used to that quickly.

Since you are looking at DCT I assume you are going the 335i route (or M3, but probably best to use another board for that). You will get the whole "you aren't driving the car if you aren't changing gear argument" for people in favour of the manual. The manual is good, and I do like it, but it is just a chore at times. If you are cruising and suddenly just want to floor it you need to rev match unless you like buying clutches. By the time you have thought this through you could have just slammed your foot down on the DCT and you are already in 3rd gear leaving rubber behind you and the box/electronics have done all the rest.

The only way you will know what you prefer is to drive both. A decent drive too, 10 minutes in these things is not enough.


Q1: Which would be cheaper to maintain?

Depends on mileage.

DCT is not that old so maybe there are few horror stories, but the clutches should not wear a lot since the whole gear change is synchronised to engine revs and plates should have matching speeds when they connect.

MT seems fairly reliable too, as with any MT its the driver that wears the clutch out.

Q2: Is there a noticeable difference in the performance between the two transmissions? I.E Straight line acceleration?

As has been said above. DCT has more gears which means shorter ratios. It can change quicker too so it does have slightly better acceleration.

Q3: Could you please explain the pros and cons between the two?
To summarise the above. Auto is easier when you just want to cruise around, MT can get dull around town. If you feel that driving a car is all about being able to press a pedal with your left foot then you will probably by a Manual.

The DCT should return slightly better economy figures too as it has more ratios, and a longer final gear. A bit quieter on the motorway too because of this. Still not long enough IMO (These things should cruise at 2k RPM @ 70mph)

[sylonien]

^ well described But here's my less precise real world take on things.
All from real world daily drives.

Q1: Which would be cheaper to maintain?
Manual I'd say.

Q2: Is there a noticeable difference in the performance between the two transmissions? I.E Straight line acceleration?

Straight line, honestly not too much difference if you're good with your manual.
But if you don't do heel 'n toe etc. then the DCT will gradually run away from you.

Q3: Could you please explain the pros and cons between the two?

DCT: option to be lazy in traffic, smoother in lazy setting, faster,
better mpg, make you look like a better driver, the sound it makes when
changing gears, auto blips / revs

Manual: cheaper to maintain, skill, better parking and the
feel it gives you, the DCT doesn't make you feel special even
though its amazing

Q4: To those of you who own a DCT… Do you ever miss slamming and crunching her into gear?

Kinda answered that above. DCT is good in every way compared to the
manual, but the manual makes you feel special when changing gears.
The DCT doesn't. Clicky d click on the paddles. Feels more like a retard*

* note, my previous M3 & 335i both were manual, currently driving DCT M3.

[Josh1a1h]

Who doesn't miss their manual!!!

I would definitely have a manual if i never sat in traffic...

But with autos being so good today and traffic getting worse in city driving... A manual is just a silly car to own... (FOR ME, Central London Driver)

[zltm089]

Originally Posted by djgandy

I own a Manual but have driven a few DCT's. The DCT box is really very good. The gear changes are extremely quick and smooth. The sound of the changes is nice, but you loose some of the garglyness from the exhaust that you get from the MT I thought.

The DCT is very odd at low speeds, because it is just an automatic manual if you like and you have to treat it like that when parking etc. You get used to it, but it isn't like an old fashioned auto where you have engine force always fighting against braking force until the point you are off the brakes. There is kind of this second guessing game going on when you first drive one where you and the box aren't quite on the same page. You get used to that quickly.

Since you are looking at DCT I assume you are going the 335i route (or M3, but probably best to use another board for that). You will get the whole "you aren't driving the car if you aren't changing gear argument" for people in favour of the manual. The manual is good, and I do like it, but it is just a chore at times. If you are cruising and suddenly just want to floor it you need to rev match unless you like buying clutches. By the time you have thought this through you could have just slammed your foot down on the DCT and you are already in 3rd gear leaving rubber behind you and the box/electronics have done all the rest.

The only way you will know what you prefer is to drive both. A decent drive too, 10 minutes in these things is not enough.


Q1: Which would be cheaper to maintain?

Depends on mileage.

DCT is not that old so maybe there are few horror stories, but the clutches should not wear a lot since the whole gear change is synchronised to engine revs and plates should have matching speeds when they connect.

MT seems fairly reliable too, as with any MT its the driver that wears the clutch out.

Q2: Is there a noticeable difference in the performance between the two transmissions? I.E Straight line acceleration?

As has been said above. DCT has more gears which means shorter ratios. It can change quicker too so it does have slightly better acceleration.

Q3: Could you please explain the pros and cons between the two?
To summarise the above. Auto is easier when you just want to cruise around, MT can get dull around town. If you feel that driving a car is all about being able to press a pedal with your left foot then you will probably by a Manual.

The DCT should return slightly better economy figures too as it has more ratios, and a longer final gear. A bit quieter on the motorway too because of this. Still not long enough IMO (These things should cruise at 2k RPM @ 70mph)

well described...


I would add...

OP if you're used to a proper manual....i would say stick with it!

However, having asked 2 friends (one with a c63 amg and the other with the current M5), they both said that the DCT does provide some "control" over the gears, as in, it would bounce off the limiter and NOT go up a gear if you floored it and don't shift with the paddle. ( which I was quite surprised with)

DCT gear change will be faster.

But for me...it will always be manual over auto/ dct/ pdk/ smg etc....

[doughboy]

Originally Posted by djgandy

If you are cruising and suddenly just want to floor it you need to rev match unless you like buying clutches. By the time you have thought this through you could have just slammed your foot down on the DCT and you are already in 3rd gear leaving rubber behind you and the box/electronics have done all the rest.

OP - always a good discussion this one!

Re the above comment, kickdown in autos/dsg is awful, that horrid pregnant pause while it shuffles down, you can't time your neck muscles properly and neither can the passengers so you all have head jerking moments when the gearbox decides it's ready to go.

Even in an auto, If i'm going to accelerate hard or overtake I always preselect the gear first using paddles (just like dropping down in a manual with a quick rev blip), then accelerate quickly but progressively without any lurching.

So kickdown is no benefit to anyone who likes driving smoothly.

And who drops gears in a manual without rev matching?? nothing to do with fancy driving, just basic car control, I was taught that on my driving lessons in 1989.

[Boz335i]

I have DCT and I've never driven it in Auto (except for when I'm on the mobile) - only joking on that last bit.

I have full control over which gear I'm in and the box doesn't change for me. Only if you stop at a junction and your still in a higher gear will it automatically select 1st or 2nd, which makes sense.

You also have the option of using the gear stick to change gear if you fancy a change from the paddles.

The DCT is quicker by a couple of tenths 0-60 which I guess would be 1-2 car lengths.

[doughboy]

Ha, that's what auto's are for isn't it? - eating and drinking whilst driving.

You never really have control of an auto / DSG, you make "requests" by pulling a paddle, then the gearbox ECU queues your request, then in time it considers it, makes a few hundred checks, ponders it for a few milliseconds and then it decides whether it will let you have the gear you have asked for.

Then when it's happy it will begin the changing process of it's own accord doing all the throttle and clutch work itself with no further input from the driver. The when the change is complete it hands the throttle control back to you to allow you to carry on.

All done quite quickly, but it's not really being "in control" it is?

It's a bit like a ships captain yelling "full steam ahead" down into the engine room....

[phil200tdi]

The dct is faster for a number of reasons.

1) gearing - shorter gearing = faster acceleration.

2) super quick shifts

3) No bog between gear shifts, full boost is maintained. Impossible to do in a manual without a No Lift Shift device.

4) brake boosting/ launch control to build boost on the start line.

But, they don't like torque! You wouldn't want to go FBO + meth without upgrading the box (spendy)... In the manual a decent clutch is good for big power/ torque!

I'd have a dct over manual everyday of the week. Mines a manual..

[Lewiss]

Originally Posted by doughboy

Ha, that's what auto's are for isn't it? - eating and drinking whilst driving.

You never really have control of an auto / DSG, you make "requests" by pulling a paddle, then the gearbox ECU queues your request, then in time it considers it, makes a few hundred checks, ponders it for a few milliseconds and then it decides whether it will let you have the gear you have asked for.

Then when it's happy it will begin the changing process of it's own accord doing all the throttle and clutch work itself with no further input from the driver. The when the change is complete it hands the throttle control back to you to allow you to carry on.

All done quite quickly, but it's not really being "in control" it is?

It's a bit like a ships captain yelling "full steam ahead" down into the engine room....

That metaphor explains an auto transmission well, but not really DCT, which isn't really comparable to an auto transmission given its mechanics. It is essentially a manual transmission which is automated by a system much smarter than 99% of drivers on the road. with a manual override for when you want full control, the decisions you choose to make via the paddles or stick are not pondered by the system, they are given to you in lightning speed, which is near immeasurable.

[djgandy]

Originally Posted by doughboy

OP - always a good discussion this one!

Re the above comment, kickdown in autos/dsg is awful, that horrid pregnant pause while it shuffles down, you can't time your neck muscles properly and neither can the passengers so you all have head jerking moments when the gearbox decides it's ready to go.

Even in an auto, If i'm going to accelerate hard or overtake I always preselect the gear first using paddles (just like dropping down in a manual with a quick rev blip), then accelerate quickly but progressively without any lurching.

So kickdown is no benefit to anyone who likes driving smoothly.

And who drops gears in a manual without rev matching?? nothing to do with fancy driving, just basic car control, I was taught that on my driving lessons in 1989.

The only pause in the DCT is the time it takes for the engine to rev up to the required speed for the gear. You actually have this pause in a Manual, but you don't notice it because you are simultaneously performing an action and it also takes so long by comparison.

Not everyone rev matches. Let the wife drive the car lol, or pretty m uch anyone for that matter. Rev matching at 4.5krpm is difficulty to do quickly and knowing the revs you need also requires a lot of time driving the car. I'd say I get it right 9/10 times now in either direction, but that is with 15 or so months of ownership. And still then low engine temps can catch me out.

Originally Posted by doughboy

Ha, that's what auto's are for isn't it? - eating and drinking whilst driving.

You never really have control of an auto / DSG, you make "requests" by pulling a paddle, then the gearbox ECU queues your request, then in time it considers it, makes a few hundred checks, ponders it for a few milliseconds and then it decides whether it will let you have the gear you have asked for.

Then when it's happy it will begin the changing process of it's own accord doing all the throttle and clutch work itself with no further input from the driver. The when the change is complete it hands the throttle control back to you to allow you to carry on.

All done quite quickly, but it's not really being "in control" it is?

It's a bit like a ships captain yelling "full steam ahead" down into the engine room....

I don't see how a manual offers more "control". You "make requests" by moving a stick into one of a few positions. There is no extra flexibility or choices you can make, infact there are fewer options as the DCT box has extra gears.

The ECU does pretty much everything in the car now. A pedal and a stick is really not control. If you want control, buy a push bike. Then you are the engine.

OP: there are vids of DCT shift times

Here's an exhuast one from the back of a 135i. As you can hear the shifts are almost instant

[djgandy]

Originally Posted by phil200tdi

The dct is faster for a number of reasons.

1) gearing - shorter gearing = faster acceleration.

2) super quick shifts

3) No bog between gear shifts, full boost is maintained. Impossible to do in a manual without a No Lift Shift device.

4) brake boosting/ launch control to build boost on the start line.

But, they don't like torque! You wouldn't want to go FBO + meth without upgrading the box (spendy)... In the manual a decent clutch is good for big power/ torque!

I'd have a dct over manual everyday of the week. Mines a manual..

Fully agree. I've read the limit for the DCT is around 440bhp (and the respective torque that goes with that). OP should bare this in mind if tuning.

[zltm089]

Originally Posted by Boz335i

I have DCT and I've never driven it in Auto (except for when I'm on the mobile) - only joking on that last bit.

I have full control over which gear I'm in and the box doesn't change for me. Only if you stop at a junction and your still in a higher gear will it automatically select 1st or 2nd, which makes sense.

You also have the option of using the gear stick to change gear if you fancy a change from the paddles.

The DCT is quicker by a couple of tenths 0-60 which I guess would be 1-2 car lengths.

how can you say you have full "control" when you say that the gearbox will "drop" a gear for you.

whether it makes sense or not is another debate!

[zltm089]

Originally Posted by djgandy

The only pause in the DCT is the time it takes for the engine to rev up to the required speed for the gear. You actually have this pause in a Manual, but you don't notice it because you are simultaneously performing an action and it also takes so long by comparison.

Not everyone rev matches. Let the wife drive the car lol, or pretty m uch anyone for that matter. Rev matching at 4.5krpm is difficulty to do quickly and knowing the revs you need also requires a lot of time driving the car. I'd say I get it right 9/10 times now in either direction, but that is with 15 or so months of ownership. And still then low engine temps can catch me out.



I don't see how a manual offers more "control". You "make requests" by moving a stick into one of a few positions. There is no extra flexibility or choices you can make, infact there are fewer options as the DCT box has extra gears.

The ECU does pretty much everything in the car now. A pedal and a stick is really not control. If you want control, buy a push bike. Then you are the engine.

OP: there are vids of DCT shift times

Here's an exhuast one from the back of a 135i. As you can hear the shifts are almost instant

by "control" we are talking control over the gears.

[zltm089]

Originally Posted by doughboy

Ha, that's what auto's are for isn't it? - eating and drinking whilst driving.

You never really have control of an auto / DSG, you make "requests" by pulling a paddle, then the gearbox ECU queues your request, then in time it considers it, makes a few hundred checks, ponders it for a few milliseconds and then it decides whether it will let you have the gear you have asked for.

Then when it's happy it will begin the changing process of it's own accord doing all the throttle and clutch work itself with no further input from the driver. The when the change is complete it hands the throttle control back to you to allow you to carry on.

All done quite quickly, but it's not really being "in control" it is?

It's a bit like a ships captain yelling "full steam ahead" down into the engine room....

SPOT ON MIKE!

[Frobius]

You could make the same arguments about manuals as above though. You decide that you want to change gear, you them have to mess about with your leg, think about what revs you want, consider the clutch bite point and how to manipulate the throttle for best effect etc etc. Difference is that a DCT can change gear a lot faster than you, no matter how amazing you claim to be at driving.

To be fair, I like my auto, but if they did a DCT on the diesel, I'd have that over a manual. Manuals are just old hat IMHO.

Plus, if manuals were that good, why wouldn't they put them in F1 cars?!

Your best bet, OP, go try both and see which you prefer.

[zltm089]

no one is saying gear changes are faster with autos! we all know that most supercars, f1 cars and fast cars have dct/auto gearboxes...

we're talking mostly about the control of gears and driving enjoyment here...

talking about driving experience...the new gt3 is pdk only!!!

[WRichieX]

Q1: Which would be cheaper to maintain?
Not sure but I would think Manual

Q2: Is there a noticeable difference in the performance between the two transmissions? I.E Straight line acceleration?
I had dual clutch on my TT and the shifts were instantaneous. Pretty impressed. But I would say that it got old real quick. Within 2 weeks, I was back to driving my WRX at the time for daily driving and garaged the TT.

Q3: Could you please explain the pros and cons between the two?
Manual - Pro: Total control of your car. Fun
Con: Sometimes sucks in heavy traffic
DCT - Pro: quick shifts, perfect shifts
Con: Boring as shit!

Q4: To those of you who own a DCT… Do you ever miss slamming and crunching her into gear?

See answer to question 2

[Lewiss]

DCT does auto downshift, but it will red line until upshift. I spent over a year in a 335d and the auto was boring as hell, and ive driven a dozen manuals over the years. However since owning the DCT 335i ive never had as much fun in a car, not driven one in manual guise though, but I can imagine the 'full control' novelty will quickly ware off as it did with previous manuals.

[djgandy]

Originally Posted by zltm089

by "control" we are talking control over the gears.

And you do have control over the gears in the DCT. It has full manual mode where the driver is responsible for changing gears! How is this not control?

The only thing you can't do though is money shift. So if the definition of control to you is the ability to completely wreck your engine with by selecting the wrong gear then no the DCT does not offer that useless feature.