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      05-02-2019, 03:32 PM   #45
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Its good video but let's critique and study this a little further.

1. BMW just made its biggest transmission purchase in history
2. BMW racecars all use sequential transmissions
3. DCT hasn't been developed for over 500 hp
4. BMW tells shareholders every car in the line up can be hybridized
5. BMW must make efficient cars due to regulations

Here's the picture if you haven't deduced it already. It's cheap to buy in bulk. Using on transmission on every car in the line up means you can make a big bill order and reduce costs.

2. BMWs SMG broke a lot but it is still the fastest shift time they have sold and with a modern cpu attached and a reliable pump it would be the best performance transmission. It wouldn't be the smoothest but I'm assuming we are here because we want performance. Hydraulic pump and dog clutch sequentials are still the transmission of Porsche BMW and every other race car. 20 years of development to improve SMGs for street use would have been expensive and have limited application (M cars) but it would be much better than ZF8.

3. DCT likewise hasn't been used in racing for a while but it's smoother than SMG and nearly as fast which makes it a good option for street cars. However, development of a new one for modern HP and torque is expensive with limited application.

4. ZF8 has the ability to remove the slush box and apply an electric motor. Again one transmission can be used on every vehicle in BMWs line up hybrid or ICE.

5. ZF8 has a nice highway gear and 6% efficiency boost over the ZF6 so they can report reduced emissions.

6. No manual transmission is rated for 500 hp and BMW isn't spending money to develop a new one, opting instead to reduce HP on the next M3 if manual is chosen.

Essentially BMW has opted to end the traditional use of Motorsport tech in street cars and just said ZF8 is good enough. It's pretty good sure but it's also pretty soulless. Slamming gears in the SMGs highest setting is fun and satisfying. Same with the DCT. I don't even need to mention a stick.

ZF8 is a soulless mass produced commuter transmission and BMW is cutting big costs ( and still raising prices!) by putting it in the M5 and soon the rest of its line up.

There is no question the 3 transmissions I listed above are/could be better than ZF8 at spirited driving. BMW has decided that 'fun' is not profitable and won't be developing any more Motorsport tech for street use.

Everyone should bitch at BMW about this. That's the whole point of the M brand. BMW wants to just make money off of the name without giving it any meaning.

The next step is a FWD 3 series to cut costs too.

This is IMO unacceptable. BMW has never made more money than last year and they can afford to race, develop a manual transmission or whatever they want.

They just want to save money. If they don't change buy BMW stock not cars.
Definitely a very thoughtful and laid out response. I agree and I don't agree.

Here is my main thing, competition. It is really increasing, Tesla is making a strong push, I almost feel like BMW had to do this to make a good product on the street. On a mechanical engineering level, while the same base transmission can be used, a lot of differences exist vehicle platform to vehicle platform (linkages, tuning, placement etc...). Hopefully be leveraging a common design, more thought can be put into other engineering areas in the vehicle. For example, greater focus on the ///M trans!

However, here is where I totally agree. ///M. That needs to be something special or even marketed in a way that the technology backs it up with performance.

It will be interesting to see what happens with the new M3/M4.
Well a ZF8 in a 328i is fine or even a 335i.

It's just the M name is becoming a badge and an upcharge compared to what it was, which used to mean homologated race car.

The e60 M5 got you F1 trans and engine. F80 has the GTE/GTLM engine, and I like it don't get me wrong, but the trans and weight and AWD kind of makes you scratch your head and wonder where's the dogclutch or DCT to complete the package.

Essentially what you are saying is true: BMW has left the niche stage and entered into mass market growth. I've accepted that but it would be nice to see the M brand closer to its origins. Ultimately a modern M5 needs to get the exec on a lease to resign for a new one and he won't if his DCT is shaky at stoplights. He wants a Badge and a comfy ride, and doesn't know what F1 is, so a V10 from an F1 program is meaningless to him. An SMG is a rough and bumpy. ZF8 is smooth and he doesn't think about it. THATS why BMW put it in there. Along with its cheap. Nothing to do with Motorsport applications.

I complain by the modern M cars do share less with production cars than ever before HOWEVER where it counts you're seeing a watered down approach. The M335i and M3 engine are pretty similar, which is fine, but I'm well aware they're doing it to cut costs, not because it's a race engine like the E9x M3 had.

If this trend continues I'm not going to be buying them because at this point a tuned 240i is closer to a race car (240i race at Nurburgring 24h) than any of the M cars and it costs less.

I still like M cars but Ive caught on to the changing winds.
I'd fully agree with what you just said. Worded it well too, wish BMW was reading this.

Looking at the homage of what M cars were in their time, not looking back on an M car being 10 years old today, but back in their prime, they were an absolute breed of special, they were completely different. To your point, literally an F1 engine in the E60, people still stop to watch that car in downtown Chicago.

Even looking at a B58 M340i X-Drive and an F80 M3, toss in a JB4 and methanol on the 340, and you are making some serious power, quite reliably too, why am I spending another $25K for the M?

M-Sport/Performance and ///M are getting very close to each other. When taking a step back, it is a phenomenal marketing effort, but something raw and unadulterated needs to come out of BMW. Call it the ///F for all I care. Maybe this is where they are trying to go with the Competition, CS, GTS etc...

It's also hard when (IMO), BMW is truly making the best product on the road, they don't genuinely need to be better than what they are doing, so why do it? Do they want to play in the land of exotics? The E60 M5 was really a Lambo with 4 doors at the end of the day. They are always cautious in this territory. I wouldn't consider an i8 to be all of that "special" in the world of fascinating vehicles.
Yeah that's probably true. I'm trying to figure out why there are 5 tiers of M cars when before there was one.

The M550i badge is obviously to parallel the Audi S6 to get more people to pay for a bigger engine. IMO the new M240i etc tier is pretty tempting for what you get. Just new springs and a flash and you've got a hell of a car.

But then M3, M3 competition, M3 CS, M3 CSL.

My thought was originally the F10 M5 was a bit underwhelming. It gained 200 lbs over the e60 and 50 hp. The turbo V8 sounded muffled and then they piped it in and it sort of damaged the brand. You talk to non-BMW guys and BMW is the 'engine through the speakers brand'. The competition was sort of a course correction/damage control type of thing giving it the power boost it needed and better suspension.

Then I think somebody decided the M cars should compete with Porsche and the idea Of the 5 tier M car emerged to rival Porsche's Base-S-GTS thing.

Idk. I worry BMW is getting to big and watering down themselves they could end up like Cadillac where they just can't figure it out anymore e
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      05-02-2019, 03:36 PM   #46
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Does the M5 use this box?
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      05-02-2019, 03:51 PM   #47
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Once you flash XHP on this thing, it's takes it to a whole new level as well. Obliterates most DCTs I've driven.

BMW uses these things in unmolested form in the M235i/M240i Racing Cup. That should speak a lot to how durable and amazing these transmissions are.
No XHP maps for 330i xDrive
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      05-02-2019, 04:07 PM   #48
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Does the M5 use this box?
Yes
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      05-02-2019, 04:18 PM   #49
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Idk... I've driven a few DCT cars (e92, f80, GTR, 458, GT3, Huracan)

the ZF8 in my F30 was nowhere near as quick on downshifts as those cars. might just be a software thing as someone above said.
Consistent with my experiences with DCT/PDK vs ZFs too. All the ZFs have been in a "regular" 320/330, but were really slow and lacked tactility.

I like that the DCT/PDK experience isn't so smooth that you can't feel anything - just my personal preference, but the movement away from DCT in the M cars is a bad thing IMO.

One of the main reasons I am considering an M2C or M2CS at the end of my F80 lease - I would rather get the DCT-equipped car.
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      05-02-2019, 05:02 PM   #50
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Originally Posted by SleepingBMW View Post
Yeah that's probably true. I'm trying to figure out why there are 5 tiers of M cars when before there was one.

<snip>
^^This B/c Marketing has taken over product development.

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Originally Posted by SleepingBMW View Post
But then M3, M3 competition, M3 CS, M3 CSL.

<snip>
It's crazy. M use to be the best BMW could do now its...

M###i = body kit and larger engine

M# = body kit, larger engine, + HP, + tuned suspension but adaptive so we can still haul the family

M# Competition = M# + HP + stiffer suspension but still thinking about the family

M# CS = stripped down/lightened up M# Competition?

M# CSL = M# CS - rear seats + roll bar?
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      05-02-2019, 05:33 PM   #51
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I can't stand these slushbox comparisons to dual clutch boxes. I've worked for BMW & Porsche for almost the last two decades, and my 10th BMW arrives in June. Not tooting my own horn here, just conveying my professional and personal experience for perspective.

No torque converter box is anywhere close to matching a dual clutch box when it comes to shift times and rev matching. I haven't driven a new M5 yet, but I don't need to. All those "journalists" saying you won't miss the DCT in the M5 are off their rockers. Drove a new X5M recently, great car, trans is still lacking from a performance standpoint, but acceptable for a performance SAV/SUV.

DCT boxes have come a very long way, as has PDK boxes. PDK boxes have virtually eliminated any of the old herky-jerky in city driving. DCT still needs some improvements in this area, but it's hardly as bad as any of the old SMG's or early dual clutch boxes. I drive PDK Panamera's, 911's, & 718's every day in traffic. They are every bit as comfortable and smooth as the ZF 8 speed is in our 2019 330i xDrive touring with the sport automatic. PDK upshifts are faster AND smoother than the ZF 8 speed, and the downshifts are waaaay faster and smoother. I can't even say that the ZF is better just rolling down the highway.

Side note, the great ratios between 5th-6th in the ZF are just too far apart. I realize 6-8 are overdrive gears, but the gap is too much b/t 5-6. It annoys the hell out of me.

Long story short, if some executive feels a current dual clutch box is too harsh, they bought the wrong car. That's why the 550 exists.
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      05-02-2019, 06:58 PM   #52
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ZF8 in my G30 is very good, no other real experience to compare so hard to say otherwise
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      05-02-2019, 07:08 PM   #53
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I enjoy the 8HP in the X3. Best auto trans I have experienced. Better than the Aisin 8 speed in my Touareg and better than the 7G-Tronic in my Benz.

I disagree that BMW should make transmissions in house like Mercedes. The examples above are a reason for this view. The 9G-Tronic is the latest from Benz, and it is OK, but not class leading.

At the moment my feeling is that the 8HP in the X3 is a better solution than the 9G-Tronic in the M-B GLC.
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      05-02-2019, 07:31 PM   #54
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So the 8HP50 variant only handles 500 Nm Max? That's only 370ft-lb! The E90 6HP26 was rated for 600Nm! Well that's some bs if you ask me...
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      05-02-2019, 07:50 PM   #55
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2. BMWs SMG broke a lot but it is still the fastest shift time they have sold and with a modern cpu attached and a reliable pump it would be the best performance transmission. It wouldn't be the smoothest but I'm assuming we are here because we want performance. Hydraulic pump and dog clutch sequentials are still the transmission of Porsche BMW and every other race car. 20 years of development to improve SMGs for street use would have been expensive and have limited application (M cars) but it would be much better than ZF8.
I might be missing something, but unless you're talking about the race-prepared, straight-cut teeth transmissions, the DCT is faster than the BMW SMG's that were used on the E36 and E46 M3 (single clutch automated transmissions) in shifting. They both have two clutches and helical gears.

The BMW SMG I/BMWSMG II/Audi R Tronic/Lamborghini e gear etc. transmissions all have shift times in the 150-300ms range and are basically dead because they're painfully jerky and slower than dual clutches, although they perhaps enjoyed a heyday in the late 1990s-2007 period before DSG/DCT came around. The Lamborghini Aventador is probably the last production car to have one, after the smart fortwo finally got a dual clutch.

Although jerky shifts feel more "real", it doesn't necessarily mean faster performance. I drive three pedal manual but would not put the ZF 8 into the "soulless mass produced commuter transmission", simply because the shift speeds are so good, even if it is super smooth. Then again, I contrast with ancient 3/4 speed autos and how 1-second long downshift reaction times would be sold as "tiptronic". I agree with chassis on the "in house not always better" - mainly based on Mercedes experiences as well, although with the 2-year-older 7G-Tronic, which was significantly slower and jerkier than I hoped for such a modern car. Also, Porsche somehow managed to acquire a 5G-Tronic on the 911 for a while, so BMW could license out one of the exotic transmissions if they really wanted.

You can watch videos of the smart fortwo 0-60 single-clutch automated manual, it's comical how long the shifts are.


If there's one single transmission that killed the stick shift, it is indeed the ZF8. You now need to sacrifice 2-3MPG's and 0.2s usually in the 0-60.

One anomaly I've found is, if the 7DCTs are so good, why do they still get 1 MPG worse than the 6MT on the EPA tests? M2 DCT is worse MPG, M4 DCT is worse MPG, so weird.




Quote:
True, though BMW doesn't have access to them, the fact they won't do what those other sports car companies did and develop a DCT for modern cars really tells you all you need to know about How bmws execs see the brand over the next five years.

I'd want to see the am division spin off to compete more with Porsche and Ferrari but BMW sees it as slap a few edgey design elements, a tune, and a price hike for printing money.
Happily for shareholders and unfortunately for sports car enthusiasts, companies all exist to eventually produce profits and results for their shareholders. When the halo effect and branding power of subsidizing your low-volume sports cars with your high-margin SUVs pays off in higher SUV sales, then you do it. When siphoning off some of those profits to R&D a slightly more technologically advanced cargo box in the X5 trunk or better air suspension or 360-degree cameras for the large vehicles is more worth it, executives will direct the money there.

BMW only makes about ~$5k profit per vehicle, Porsche makes $15K and has all of VW AG to share tech with, so there is less wiggle for BMW. Even so, the vast majority of Porsche profit is purely due to the badge and selling boatloads of Cayennes and Macans.

I'm not sure what the exact R&D cost of a new DCT would be, but the volume of DCT usage is surprisingly quite low for BMW. Making it work everywhere is not even that worth it to Audi with all their parts sharing sometimes, as they stick the S5 and RS5 with the ZF 8 as well since it accelerates just as nicely and they didn't have any R Tronic/DCT that fit the torque requirements, and works in the monstrously powerful Hellcats too. I wonder if there's a fundamental mechanical trade off in that a torque converter is a force multiplier while a clutch is fundamentally a torque divider, that gives torque-converter autos an advantage on takeoff or in shifts.

I'm also still a little surprised that it's so hard to just program a DCT to be ultra-smooth (can't you just rev match perfectly? There is already some DBW delay anyway), but what do you know.

Last edited by EstorilM240; 05-02-2019 at 08:00 PM..
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      05-02-2019, 08:37 PM   #56
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Quote:
Originally Posted by mose121 View Post
I can't stand these slushbox comparisons to dual clutch boxes. I've worked for BMW & Porsche for almost the last two decades, and my 10th BMW arrives in June. Not tooting my own horn here, just conveying my professional and personal experience for perspective.

No torque converter box is anywhere close to matching a dual clutch box when it comes to shift times and rev matching. I haven't driven a new M5 yet, but I don't need to. All those "journalists" saying you won't miss the DCT in the M5 are off their rockers. Drove a new X5M recently, great car, trans is still lacking from a performance standpoint, but acceptable for a performance SAV/SUV.

DCT boxes have come a very long way, as has PDK boxes. PDK boxes have virtually eliminated any of the old herky-jerky in city driving. DCT still needs some improvements in this area, but it's hardly as bad as any of the old SMG's or early dual clutch boxes. I drive PDK Panamera's, 911's, & 718's every day in traffic. They are every bit as comfortable and smooth as the ZF 8 speed is in our 2019 330i xDrive touring with the sport automatic. PDK upshifts are faster AND smoother than the ZF 8 speed, and the downshifts are waaaay faster and smoother. I can't even say that the ZF is better just rolling down the highway.

Side note, the great ratios between 5th-6th in the ZF are just too far apart. I realize 6-8 are overdrive gears, but the gap is too much b/t 5-6. It annoys the hell out of me.

Long story short, if some executive feels a current dual clutch box is too harsh, they bought the wrong car. That's why the 550 exists.
You can bring out the jerkiness in the PDK pretty easily by driving a certain way or letting off the gas at certain points. Granted the Macan's PDK is slightly different than the ones in the 911 but you cannot completely eliminate it because it's just how a DCT is. A ZF8 will be smoother for most people who care very little for performance aspects brought on by a DCT. Not to mention, those people who don't know their cars won't be able to tell between a DCT and a Torq Automatic. Hell I had to explain it slightly to my father as he had no idea. For the majority of the masses, the difference between the ZF8 Speed and a DCT like the PDK is extremely little.

I love the M-DCT in the F8x. It is something I don't think BMW should just abandon and let go. There isn't anything else like it.

Haven driven the new F90 M5. There isn't anything wrong with the ZF8 in that car since BMW M tweak it. I love the up shifts but there is still something missing when I drove it, I miss the feel of the M-DCT in my M3.
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      05-02-2019, 08:56 PM   #57
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Yet somehow this ZF8 tranny shares DNA with the ZF9 speed in the Chrysler/Jeep which SUCKS beyond measure even after a couple of reprogramming versions. It didn't know which gear to hold or when to upshift or downshift. It's a wonder why FCA didn't change over to this.
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      05-02-2019, 09:04 PM   #58
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Quote:
Originally Posted by mose121 View Post
I can't stand these slushbox comparisons to dual clutch boxes. I've worked for BMW & Porsche for almost the last two decades, and my 10th BMW arrives in June. Not tooting my own horn here, just conveying my professional and personal experience for perspective.

No torque converter box is anywhere close to matching a dual clutch box when it comes to shift times and rev matching. I haven't driven a new M5 yet, but I don't need to. All those "journalists" saying you won't miss the DCT in the M5 are off their rockers. Drove a new X5M recently, great car, trans is still lacking from a performance standpoint, but acceptable for a performance SAV/SUV.

DCT boxes have come a very long way, as has PDK boxes. PDK boxes have virtually eliminated any of the old herky-jerky in city driving. DCT still needs some improvements in this area, but it's hardly as bad as any of the old SMG's or early dual clutch boxes. I drive PDK Panamera's, 911's, & 718's every day in traffic. They are every bit as comfortable and smooth as the ZF 8 speed is in our 2019 330i xDrive touring with the sport automatic. PDK upshifts are faster AND smoother than the ZF 8 speed, and the downshifts are waaaay faster and smoother. I can't even say that the ZF is better just rolling down the highway.

Side note, the great ratios between 5th-6th in the ZF are just too far apart. I realize 6-8 are overdrive gears, but the gap is too much b/t 5-6. It annoys the hell out of me.

Long story short, if some executive feels a current dual clutch box is too harsh, they bought the wrong car. That's why the 550 exists.
Well said. PDK is light years ahead of my 340i's 8 speed auto.
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      05-02-2019, 11:20 PM   #59
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Quote:
Originally Posted by mose121 View Post
I can't stand these slushbox comparisons to dual clutch boxes. I've worked for BMW & Porsche for almost the last two decades, and my 10th BMW arrives in June. Not tooting my own horn here, just conveying my professional and personal experience for perspective.

No torque converter box is anywhere close to matching a dual clutch box when it comes to shift times and rev matching. I haven't driven a new M5 yet, but I don't need to. All those "journalists" saying you won't miss the DCT in the M5 are off their rockers. Drove a new X5M recently, great car, trans is still lacking from a performance standpoint, but acceptable for a performance SAV/SUV.

DCT boxes have come a very long way, as has PDK boxes. PDK boxes have virtually eliminated any of the old herky-jerky in city driving. DCT still needs some improvements in this area, but it's hardly as bad as any of the old SMG's or early dual clutch boxes. I drive PDK Panamera's, 911's, & 718's every day in traffic. They are every bit as comfortable and smooth as the ZF 8 speed is in our 2019 330i xDrive touring with the sport automatic. PDK upshifts are faster AND smoother than the ZF 8 speed, and the downshifts are waaaay faster and smoother. I can't even say that the ZF is better just rolling down the highway.

Side note, the great ratios between 5th-6th in the ZF are just too far apart. I realize 6-8 are overdrive gears, but the gap is too much b/t 5-6. It annoys the hell out of me.

Long story short, if some executive feels a current dual clutch box is too harsh, they bought the wrong car. That's why the 550 exists.
If I was sober I would type the exact same thing (apart from the Porsche daily experience )

The reason I got my M6 was that it had a V8 and a dual clutch. This was important to me and out weighed every other positive that other manufacturers could bring to the table.

I have driven the F90 a bit and while the gearbox is good, I feel like it is now just an Audi RS4/5/6/7 with a BMW logo.
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      05-02-2019, 11:31 PM   #60
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Originally Posted by EstorilM240 View Post
I might be missing something, but unless you're talking about the race-prepared, straight-cut teeth transmissions, the DCT is faster than the BMW SMG's that were used on the E36 and E46 M3 (single clutch automated transmissions) in shifting. They both have two clutches and helical gears.

The BMW SMG I/BMWSMG II/Audi R Tronic/Lamborghini e gear etc. transmissions all have shift times in the 150-300ms range and are basically dead because they're painfully jerky and slower than dual clutches, although they perhaps enjoyed a heyday in the late 1990s-2007 period before DSG/DCT came around. The Lamborghini Aventador is probably the last production car to have one, after the smart fortwo finally got a dual clutch.

Although jerky shifts feel more "real", it doesn't necessarily mean faster performance. I drive three pedal manual but would not put the ZF 8 into the "soulless mass produced commuter transmission", simply because the shift speeds are so good, even if it is super smooth. Then again, I contrast with ancient 3/4 speed autos and how 1-second long downshift reaction times would be sold as "tiptronic". I agree with chassis on the "in house not always better" - mainly based on Mercedes experiences as well, although with the 2-year-older 7G-Tronic, which was significantly slower and jerkier than I hoped for such a modern car. Also, Porsche somehow managed to acquire a 5G-Tronic on the 911 for a while, so BMW could license out one of the exotic transmissions if they really wanted.

You can watch videos of the smart fortwo 0-60 single-clutch automated manual, it's comical how long the shifts are.


If there's one single transmission that killed the stick shift, it is indeed the ZF8. You now need to sacrifice 2-3MPG's and 0.2s usually in the 0-60.

One anomaly I've found is, if the 7DCTs are so good, why do they still get 1 MPG worse than the 6MT on the EPA tests? M2 DCT is worse MPG, M4 DCT is worse MPG, so weird.






Happily for shareholders and unfortunately for sports car enthusiasts, companies all exist to eventually produce profits and results for their shareholders. When the halo effect and branding power of subsidizing your low-volume sports cars with your high-margin SUVs pays off in higher SUV sales, then you do it. When siphoning off some of those profits to R&D a slightly more technologically advanced cargo box in the X5 trunk or better air suspension or 360-degree cameras for the large vehicles is more worth it, executives will direct the money there.

BMW only makes about ~$5k profit per vehicle, Porsche makes $15K and has all of VW AG to share tech with, so there is less wiggle for BMW. Even so, the vast majority of Porsche profit is purely due to the badge and selling boatloads of Cayennes and Macans.

I'm not sure what the exact R&D cost of a new DCT would be, but the volume of DCT usage is surprisingly quite low for BMW. Making it work everywhere is not even that worth it to Audi with all their parts sharing sometimes, as they stick the S5 and RS5 with the ZF 8 as well since it accelerates just as nicely and they didn't have any R Tronic/DCT that fit the torque requirements, and works in the monstrously powerful Hellcats too. I wonder if there's a fundamental mechanical trade off in that a torque converter is a force multiplier while a clutch is fundamentally a torque divider, that gives torque-converter autos an advantage on takeoff or in shifts.

I'm also still a little surprised that it's so hard to just program a DCT to be ultra-smooth (can't you just rev match perfectly? There is already some DBW delay anyway), but what do you know.
Weight would play a huge roll. Do we know the weight of the DCT box vs the 6MT?
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      05-03-2019, 06:16 AM   #61
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Quote:
Originally Posted by ItsGary View Post
Weight would play a huge roll. Do we know the weight of the DCT box vs the 6MT?
DCT weighs 55lbs more than the 6MT.
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      05-03-2019, 08:47 AM   #62
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Quote:
Originally Posted by baege View Post
zf8 in.my.m240i has almost converted me to a paddle guy...almost
Ditto in my m235, always been a manual guy. DCT nice but a bit rough for daily use, built for the track and better than the ZF8 at that. I occasionally miss a manual, except in traffic
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      05-03-2019, 08:53 AM   #63
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The new m4/m3's will have the ZF8 like the F90 m5's ? I would think so 5 ers 600 hp m3/4 500
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      05-03-2019, 11:26 AM   #64
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Quote:
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Quote:
Originally Posted by ItsGary View Post
Weight would play a huge roll. Do we know the weight of the DCT box vs the 6MT?
DCT weighs 55lbs more than the 6MT.
55lbs is a lot. That's were your 1mpg increase/decrease comes from
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      05-03-2019, 12:17 PM   #65
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Quote:
Originally Posted by ItsGary View Post
55lbs is a lot. That's were your 1mpg increase/decrease comes from
True, I think that's a factor, though I suspect not the major factor. The ZF8 is 20/31lb more than 6MT (on M240i/230i) but gets a +3MPG boost instead of -1MPG. The 24lb (<1%) weight difference between ZF8 and DCT7 is hard to explain a 4MPG (>10%) differential.

I think there's something else that is inefficient about the DCT vs. the ZF. Maybe the DCT's more aggressive shift programming or lack of a super tall 8th gear hurts it. I have driven a DCT M2, but not long enough and not in normal enough traffic to intuitively learn the programming.

To check this theory, I did the math for cruising RPM at 60MPH: ~1825rpm on the DCT for the M2 and 2300rpm on the 6MT (they have the same final drive ratio, but 6th gear on the manual is 0.85 and 7th on the DCT is 0.67). Very odd to me how cruising at 26% lower revs does not make up for the 55lb difference. If you think cruising at the higher revs is more efficient for the M engines, then the DCT should just downshift to 6th.

For the M240i, the cruising RPM at 60MPH is ~2130rpm (6MT) or 1475rpm (8AT), a 44% rev difference, which is good for a 10% highway MPG boost.

Last edited by EstorilM240; 05-03-2019 at 12:30 PM..
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      05-03-2019, 12:53 PM   #66
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I love the LCI ZF8 in my F31 but I definitely prefer the PDK in a 2017 Macan Turbo I drive every now and then.
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