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View Full Version : VW’s to run DSG’s vs. a std. Automatic on the new TDI’s


xcel
02-06-2008, 09:53 AM
Hi All:

___Not 100% but close. It appears the new Jetta TDI headed our way will be equipped with a 6-speed DSG ;)

___Good Luck

___Wayne

Right Lane Cruiser
02-06-2008, 10:06 AM
As long as a good manual with the correct gearing is available... ;)

Maxx
02-06-2008, 11:33 AM
I'm a purist, but from everything I've read, the DSG is a step up from the manual. Should probably be better regular-guy fe, but I'm not sure that neutral coasting is possible.

koreberg
02-06-2008, 02:16 PM
@maxx, its only a step up if you can easily shift it into neutral and it allow you to shift when you want to with no override.

Maxx
02-06-2008, 02:37 PM
@maxx, its only a step up if you can easily shift it into neutral and it allow you to shift when you want to with no override.

You're absolutly right. I'm not sure of all the ins and outs of the DSG, but for fe with average Joe-Shmoe driver, there should be an increase in fe because of quicker shifting and no fluid/turbine loss. The DSG system is an automated manual transmission with a clutch. It can shift quicker and with less loss than a driver in a manual tranny car. And if I'm not mistaken it's 2 mode - full auto, and paddle shift - which relies solely (with maybe a high rpm auto-shift) on the driver for the shift points. This sure ain't your daddy's automatic.

All that being said, I'm still not sure if it has a usable/easy neutral. It might, I don't know.

lightfoot
02-06-2008, 03:41 PM
I agree that as an automatic the DSG could yield improved mpg over the usual fluid-drive automatics by reducing transmission losses.

But I'm skeptical that quick shifting aspect will do anything for FE. I realized that I usually do my accelerations as a series of mini P&G's, coasting in neutral for a bit between gears. Quickly getting to the next gear does nothing for my FE s far as I can see. And as pointed out above the shifting may be programmed for higher rpms than we want to shift at.

Also, for Joe Average Driver the quick-shifting may encourage harder accelerations.

IOW, it's a sporty-driving thing.

Right Lane Cruiser
02-06-2008, 06:17 PM
Wayne and I have a different viewpoint on quick shifting -- both of us snap from gear to gear with as little delay as possible to avoid as much idling as possible. I got a kick out of watching Wayne do it for the first time since I've been doing it myself. :)

I'm not sure I can see much value in a pause between gears considered a "glide" -- it doesn't seem like it would be long enough to make it worth it?

One of my main issues with any auto transmission is the loss of bump starting. This is SO much more efficient than the 12V reduction gearing start it is just amazing. I'm going to really really miss the manual transmission when I end up having to buy something without it to get to the next level of efficiency because of the involvement it allows, but right now I don't think there is anything out there that can beat its flexibility.

lightfoot
02-06-2008, 09:00 PM
I'm not terribly worried about idling because 30mph at 0.2gph works out to 150mpg, which is OK. I do worry about any transient higher rate of consumption as the ICE drops to idle. I'm more concerned about wear to the trans from rushing shifts (clearly the DSG design avoids this kind of wear). And I'm not in a big hurry to get to speed anyhow, and I'm afraid rushing shifts may lead me back into rocket starts.

Obviously the length of the glide-lets depends on the terrain: shorter while going uphill, longer on a gentle downhill that isn't steep enough to merit a FAS.

My other concern about the DSG comes from 25 years of using the sequential gearboxes on motorcycles almost daily. On a motorcycle, you can't get to neutral except by clicking down to between first and second, and the trans really does not like to do that at speed. So gliding or FAS are really only possible if you hold the clutch in, which would be tiring. You can skip gears but that gets tricky because again the trans doesn't like that, and smoothing things out by double-clutching is impossible because there is no neutral between gears.

An automotive MT allows you to go from any gear to neutral and/or to any other gear, and to do so at almost any rpm you choose. I think we forget about that flexibility, some of which is very useful for hypermiling. I'm not sure the DSG would offer adequate flexibility for hypermiling, though I am convinced it would improve mpg for those who don't think much about driving for mpg and just point the car and push on the gas pedal.

bomber991
02-07-2008, 01:39 AM
Hi my name is Joe and I'm an average driver. What's a DSG?

xcel
02-07-2008, 02:19 AM
Hi Bomber991:

___The following should help and yes, I like them ;)

Volvo launches their version of DSG – American’s need not apply :( (http://www.cleanmpg.com/forums/showthread.php?t=8175)

BMW’s Dual-Clutch 7-speed manumatic transmission is about to make waves (http://www.cleanmpg.com/forums/showthread.php?t=8454)

___I can do a News write-up on the VW’s DSG inner workings and the new production schedule in Germany but it would be yet another duel clutch tranny article for the most part …

___This is what you might like to read though … The Jetta TDI Cup vehicle will use the all-new, high-tech 2.0-liter four-cylinder TDI clean diesel engine outfitted with a six-speed automatic DSG® transmission. If they are outfitting the bone stock Jetta TDI other than the track safety fitment for the Cup, you can bet the DSG will be in the TDI’s on the showroom floor later this coming summer too ;) They are less expensive, lighter, more fuel efficient and far smoother than a std. automatic.

___Good Luck

___Wayne

shifty35
02-07-2008, 09:36 AM
DSG = Dual Sequential Gearbox?

Dual Synchronous Gearbox?

Something along those lines eh? I see it as maintenance hell either way. Not like current automatics are *easy* to work on either... ;)

Vooch
02-07-2008, 03:34 PM
VW/Audi have had these tranny's for at least 10 years. the bugs are worked out



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