Thread: DCT tranny
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      11-23-2012, 12:59 AM   #7
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Drives: 340i M-sport AT
Join Date: Mar 2006
Location: Chicago

iTrader: (1)

Originally Posted by 949 View Post
if they put a double clutch transmission in im going to buy this car. right now im stuck between the manual and auto transmission.

i love stick but others in the family cant drive manual.

i know ill miss the stick so i would compromise with a DCT tranny.

anyone else have this manual / auto dilemma?
Edited for corrections:

Yes, I too had this decision.
I'm an MT driver at heart, but after reading up on the ZF sport AT and then trying it out, I was sold on trying it.

I've not tried a BMW DCT, but I've tried many Audi DSG's and the one in the S4. The S4's is a very nice and quick trans.
But the ZF is it's equal in speed. The ZF's advantage is that it's smoother due to having a torque converter.
Plus, the ZF can do multi gear downshifts and skip gears whereas the dual clutch trannies can't do it as quickly not. In the ZF if you go from 6th to 3rd it will only need to do one shift and you're in 3rd. The dual clutch needs to shift between odd and even gear shafts, so depending on which gear you are in it may take 1 or 2 shifts to get the lower gear you want.
The ZF feels faster on downshift because it can skip straight through to the lower gear.
Upshifts are just as fast with the sport ZF as dual clutches at 200 milliseconds per shift.
Fastest shifts are done when in sport drivers mode or DS trans mode.
Smoothest shifts are in comfort mode and D/auto sport mode.
Manual mode is also just as quick.

After driving mine for 3K miles I find the sport AT very satisfying, smooth when I want it, and fast when I want it.
But, it does not give me the same feel and driving experience as an MT, and it can't simply because there is a different mode of operation between an AT and MT. With MT you do the shifting and clutch work and you decide when to up or downshift. Even in manual mode with the AT it's not the same feel as there is no clutch to be used.

Will I ever go back to MT? Yes. Not because the sport AT sucks, just because I may want to go back to moving levers and engaging the clutch.
It's a different feel that's all.
The ZF AT is fantastic and I'm glad I choose it as I wanted to try out the BEST AT in the market. And now I know, and I can judge the differences between MT and this type of AT much better than before.

I need to take my 335i in to the shop though, as it feels like the rev matching downshifts aren't as smooth as they were when new.
Could be a programming thing, but maybe it's mechanical and the fluid level is not correct.

Last edited by RPM90; 11-23-2012 at 04:45 AM.