I had to sit in some long { think escape from nyc } mostly-stopped traffic the other day and I got to thinking about the fact that the DSG tanny is always somewhat engaged. * let your foot off the brake, there's always a little driveline torque avail. to start pulling you forward - meaning one of the 2 clutches is always dragging a little. Versus a manual where when you are sitting - either you are postholeing your left leg or you've got it sitting in neutral and there is zero clutch engagement.

Considering the DSG is more like an 'automated' manual versus the older hydrostatic/TC system this means that to provide that torque, there's going to be additional heat and wear.

So my { seriously nitpicky question } is this - is it ok { a good idea? } in heavy traffic to just pop the car from D to N and back again when needed?

Or does it really just not make a darn bit of difference as shifting from D to N and back again causes other wear that outweighs the wear of having one of the 2 clutches lightly engaged while stopped?

 

When you let your foot off the brake, the DSG automatically adjusts clutch/throttle position in order to give you the sensation of an automatic. There is no driveline torque being held back when you're stopped.

If you stop on a hill, let off your brake RIGHT before you come to a stop, and you'll roll backwards. It's because once the car comes almost to a stop, the DSG puts the clutch in all the way.

Then, like I said, when you let off the brake, there is a very small pause as the clutch lets out a bit and the throttle is applied a small amount to give you the feeling of a real automatic.

 

Yup...

I tried to ask this a few months ago after my baby pulled away from me on a gravel road with the ebrake on and car in drive...It seems to me like they dont work the clutches with the hand brake like they do with the pedal? Anyone else notice it?

 

I'll second what i_baked_cookies said. The DSG's clutch actually disengages when your foot is not on the gas. As a benefit, this saves gas when you're on the road and you let off the accelerator to coast.

 

Not necessarily. If you are coasting and the clutch was disengaged, wouldn't the tachometer show the RPM at idle. Also, when you are coasting you can feel the engine braking, especially if you downshift via the left paddle. So at least one clutch must be engaged to provide engine braking.

 

Hmm, I dunno. I just saw that in a video about how DSG works (it was all done in CG). Maybe it only disengages when you press the brake? The tach would still show RPMs since it is measuring engine speed, right? But I see what you mean about downshifting while coasting. Perhaps when you downshift the car thinks you are about to request more power (i.e. passing or climbing a hill) so it re-engages the clutch? I'm gonna have to do some more reading into it.

Sources:

http://en.wikipedia.org/wiki/Direct-Shift_Gearbox

Video: http://www.youtube.com/watch?v=HcpOUV9XpbU
This is mentioned at the end, about 3:00 in. It's a really cool video though, I suggest watching it all the way through.

 

It puts the clutch in when you're about to come to a stop (5mph)... so you don't stall, obviously.

The DSG goes the EXACT same things your left foot would do... it even feathers the clutch when you floor it off the line... it'll stick to about 2000 or 3000 revs and when the clutch is all the way out then it climbs. It's like a semi-launch control.

Think of the DSG as a Japanese guy with his excellent pedalwork. He's perfect!

 

Of course! I feel retarded now for not thinking of this before.

I added a few sources to my last post too.

 

I think it actually lets the clutch in before 5mph if it figures out what you are doing, at least in manual mode. Coming up to a red light, if I take my foot off the gas to coast up to it, somewhereon the slow side of20 I notice the tach drops to around to idle and I can downshift without so much as a twitch from it.

 

When the traffic is very hard, or in a stop light, I always put in in "N", but I always try to get in back in D before I start moving again, so I dont rush the clutch to engage and start moving, like giving the clutch a little time to engage before using the throttle.

What do you think?? is there really a clutch wearing?? Am I doing the rigth thing or im overreacting?