DSG?

"Dan Stephenson" wrote

It would be more fuel-efficient than a Tiptronic auto; they're not comparing it to a "traditional" manual transmission.

I believe that DSG stands for Dual-clutch Sequential Gearbox. It's similar in operation to current Sequential Manual Gearboxes, but since it uses two clutches, the shifts are very much smoother. I believe that one clutch is used for odd-numbered gears, and another for even-numbered gears.

Audi has had one for 2-3 years. BMW is working on one, probably other manufacturers.

FloydR

Most of the fuel savings are due to the lack of the need for a torque converter, as the DSG transmission is similar to an automated manual transmission, using smart electronics. The Formula 1 cars have been using this type of transmission for some years and the consumer versions have been coming into the marketplace for several years. As in Formula 1, you can use the "paddles" in manual mode to upshift or downshift the transmission. There's still a question as to whether the CVT (continuous variable transmission) is more appropriate and less costly for non-performance cars.

But wouldn't you miss the clutch? Are you reduced to just moving the shifter around, alone?

I had a, 2006 BMW M5 with the single clutch, sequencial transmission. When I first started driving it, I was constantly lifting my left foot, looking for the clutch. Took a while to get used to.

It was ok shifting manually. The "automatic" mode was worthless, IMO. In the manual mode, you could select from 6 levels of performance each of which changed how quickly the shift was made. I never really cared for it, plus it was prone to many problems, mostly software related. I ended up trading it in on my Porsche 996TT with the 6 speed manual. I'll never look back. Love the Porsche.

RCE

The BMW trans used a single clutch...and the software was panned in virtually every article and post I've seen. However, the dual clutch DSG trans seem to be much better and with the right software, their shifts are more positive and not so rough as to give you whiplash. I understand that Audi has done a good job with their version, so you might want to try one out.

Do I "love" my clutch...not if I could get the same performance and reliability without it. Oh...and then, in a "pinch", the wife could switch cars with me (?????????).

As far as I know, this type of transmission originated at Porsche in the '60s or '70s when they were looking for a fast-shifting race car gearbox. Porsche prefers to call it the "Porsche Doppel-Kuppling [PDK]" meaning Porsche Double Clutch. At least that's the best result from my limited German skills.

There was an account of a press conference a couple years ago. A "typically well-informed" journalist asked a senior Porsche engineer if Porsche was considering the "AUDI dual-clutch" transmission. That question went over well.