03-20-2019, 12:37 PM | #1 |
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Drives: 2015 M4 Conv; 2019 M550i
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DCT vs. 8-Speed Sport Transmission
I have had my M550i for 8 weeks now and also own a 2015 M4 Convertible with the DCT. As such, I am able to compare their drivetrains directly.
I was puzzled by the choice of the 8-Speed as a replacement for the DCT in the M5 and (presumably for the) M550i - and a lot of other German performance cars for that matter. Reviewers have lauded the choice for the most part, but I was skeptical. Now that I have had ample opportunity to play with the 8-Speed, I am a believer. It's only very marginally slower-shifting than the DCT (a non-enthusiast won't notice the difference) and in slow-speed situations, it's a lot smoother and doesn't have that intermittent little hiccup from a standing start that the M4 DCT does. Philosophically, it still seems like corner-cutting to put this transmission in an M car but in practice, I can't fault it. |
03-20-2019, 06:25 PM | #3 |
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good to know
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03-20-2019, 09:02 PM | #4 |
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As a former 2016 M4 owner (I traded it for my 2019 M550i), I would agree. I actually like the 8 speed better. The DCT was jerky and clunky, especially when coming to a stop. No such problem with the 8 speed. In the M4, I usually used the Drivelogic 2 program, and liked it in traffic because it kept the car in gear, and I used the engine to forgo having to constantly brake in traffic. With the M550 transmission in Sport mode (transmission lever to the left), even when the car is still in comfort mode, the 8 speed does the same thing, and I use that now in traffic for the same reason. Both transmissions effectively operate in a very similar fashion otherwise, IMHO.
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03-20-2019, 10:59 PM | #5 |
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Maybe a little off topic but trans related. Shifting the drive knob to the left engaged manual mode and to the right re-engages auto but how about paddle shifters. Once you use paddle shifters how do you get back to auto other then letting it time out. I have moved drive knob left then right but I have to believe there is a smarter way.
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03-21-2019, 12:16 AM | #6 | |
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Quote:
Re. DCT vs 8 Speed Auto , I had DCT in my E92 335i. It was not the M-DCT but still DCT Downshifts were a bit faster, downshifting a few gears with kickdown was faster, upshifts are almost same. 8 speed shifts are smoother ( it is not always a good thing ) and no lag during standstill starts which was the only thing i did not like about DCT I was concerned I would not like the 8 speed auto when I ordered my G30 540i but I am fine with it.
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03-21-2019, 06:59 AM | #7 | |
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Quote:
I've never driven a DCT, but came from a long line of manuals (the 3-pedal kind). I really like the ability to manually downshift on hills and slowing for corners, I really hate riding the brakes, and was unsure about the ZF8. X-drive was more important to me than a manual, though. My first experience with the ZF8 was driving my new M550 off the lot, and I've had no regrets. The paddles are nice for downshifting, and the ZF8 is much faster than I ever was with my manual. |
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8-speed, dct, m550i xdrive |
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