Iker

BMW F10 M5 2016 >> DCT
BMW F90 M5 2019 >> ZF automatic 8 speed
I’m wondering why BMW stopped using DCT in M cars!
I had the chance to drive the new M5 and I am very impressed

NY09C6

DCTs generate lots of owner complaints and service appointments. The average car buyer will feel the quirkiness of them and schedule service appointments. We had my wife’s Audi DCT into service several times, all times were told the things we observed were normal. She is back in a ZF auto BMW and life is good again. No more Audi DCTs for us.

Warp Factor

I guess they would have needed to change the architecture of an existing automatic or manual anyway to make it work with a mid-engine, so they just decided to start over with with the type of transmission the automotive journalists keep raving about?

jvp

I'm not sure you actually understand what "economies of scale" means, but you're fairly incorrect with that statement. Were that the case: see the truck engines and Corvette. Zero changes between those two sets of engines? Uhhh...

We also don't know the specifics of the transmission yet, only rumors about it. It could end up being very easily reconfigured for a different mounting and engine layout. You're assuming way too much.

I'd agree with that if GM's only performance car was the Corvette. But as it turns out: it's not. They have the Camaro and the CTS(-V, etc) from Cadillac. Further, there's no reason they can't alter the transmission enough to deal with less input torque or even: fewer gears! The main cost of the transmission is the R&D for it, not the actual building/assembling it. Same goes for any other part on or in the car.

Well imagine this possibility, and it's one I speculated about 5-10 years ago, right here on CF: GM ditches their planetary automatic transmissions entirely, along with the last of their remaining manual transmissions. All in favor of some form of DCT? The exception to that would be the big diesel rigs which would continue to use the Allison (not GM...) transmission. If a DCT can be snicked into "auto" mode and just driven, why not?

I suspect GM is seeing other directions; Aston's CEO's opinion on the direction of the auto industry isn't really a big deal. ;-)

ByByBMW

They haven't. The DCT is still an option on the M4 and the M2 competition at least. There may be one or two others.

vndkshn

I completely agree. It's obvious they needed to make huge changes to accommodate the ME layout, and they are definitely trying to hit that niche. It's just a huge risk if that software isn't right (not a sports car, but see Focus, it's number 1 problem is the programing).

vndkshn

You are comparing a vehicle (Corvette) that sells what, 20-30 units a year with a truck that sells over 400k units (combining all models including GMC). So yes.. "economies of scale" applies to the engines, especially when factoring in the truck side. And don't forget Camaro in that math, since it shares the Corvette (not truck) engine.

Heavy irony.

But that tosses :"economies of scale" out the window. When you start altering the transmission that much, you start to lose alot of the sharing of parts. Plus, it's another transmission to train on, stock parts for, etc.

Case in point, back in the days (at least late 80s early 90s), if you needed a distributor cap for your mid 70s Corvette and went to the dealer, it had one part number. The EXACT same part for a BBC was a different part number, but they were interchangeable. They may have finally changed that, but I distinctly remember that because I always laughed about it.

Possible, and Ford definitely tried it. Didn't work out well for them. And while you might ignore the comments from the Aston CEO, you can't ignore the facts behind it. The ZF8 is a prime example of an automatic that is approaching DCT levels of performance (and outperforming some of them).

Foosh

On your manual observation, I agree, but I think there is a good reason why they cannot at this point in time. I don't think it's because of decreasing manual demand, because 23% manual sales (C7 number) is sizable at Corvette volumes.

I think it is because there is not currently a manual transaxle that can safely handle LT1/2 torque. It is my hope they will ultimately find a solution for later MYs.

jvp

But... the truck engines get changed quite a bit before being plopped into the Corvette and Camaro. And yet the economies of scale still work there, according to you.

Not really. I've clearly called out that I'm speculating. You're speaking as if it's fact. Keep swinging.

Again: not really. The cost of the transmission is the R&D, not the building/assembly of it. That R&D can easily be paid for across multiple car lines, even if the exact DCT parts don't get put into each car.

That has.... what to do with this conversation, exactly?

Iker

Because its concept of design is similar to the old M5
the new M4 will be revealed next year with the same design concept of the new M5 and absolutely with ZF automatic transmission 8 speed.
Actually I can tell you the performance of the new M5 is something I couldn’t believe! upshift or downshift are both fast as hell!

blipit_

It is as simple as cost. They are going to use the same 8-speed across all M vehicles. G8x M3/M4 will be getting the same transmission.

DCT are still superior in performance application, hence all high end sports cars use DCT. I had a F10 M5 with DCT and have driven the new M5. The 8speed to me feels slower(particularly downshifts), it just didn’t feel as crisp. But 8speed Auto is more smooth day to day driving. I would still prefer DCT in my sports cars.

The complaints about DCT come from normies who treat them like traditional automatics driving them in auto mode daily.

BEAR-AvHistory

They are saying they have the 8ZF to the point where it will preform-with/out-perform? the 7DCT. FWIW my BMW 7DCT was quicker shifting the my BMW 8ZF is, but a lot is in the programing.

So far most all the new M cars are running the 8ZF as the generations change. The 6MT is also going away on most except M2, M3, M4 which so far also have the 7DCT

JDSKY

Here's hoping that the transmission works flawlessly out of the gate but these things are so complex that I think it may take a bit to perfect. Software updates can definitely be an inconvenience but at least the dealer is not disassembling the car in order to implement them. Have not had my Armada's transmission updated yet but I hear it is a 3 hour service appointment.

vndkshn

At this point, I think you are being intentionally obtuse.
You used the engine example as proof of economies of scale, not me. I have no idea how many parts are or are not shared between the truck and Corvette if any. They could be completely unrelated and only share displacement. I pointed out the Camaro uses the same engine as the Corvette, not the truck.
You are assuming that it would be little to no change to use this transaxle in another vehicle and that would result in economies of scale. Keep swinging.
So no R&D to change the trans (as you mentioned, different case, possibly different number of gears, possibly different ratios, different programing, the list goes on an on) for a different vehicle? Interesting.

It was an example of how GM has screwed up the scale concept before. There are several others.

sly1

It comes off as fake because it is fake. Porsche and others try to replicate the exhaust sounds of a racing exhaust. So they have the computer inject a few drops of gas over the exhaust under specific conditions to get the popping sound. In order to maximize performance at redline, where race cars live, a racing cam has a significant amount of overlap between the exhaust and intake valve openings. thereby maximizing intake valve duration. The first production car that I had with a racing cam was a 1968 Z28. Two telltale signs of a racing cam: engine lopping and popping sounds made by unburnt fuel in the exhaust at low RPM. In the last Petite LeMans race I attended in Baltimore, you could see exhaust flames and hear the popping as the cars slowed for a hairpin.

vndkshn

I think fewer and fewer BMW drivers want to drive manuals at all. I'm an instructor for BMWCCA and I don't see many new generations of BMWs at the events, even M cars. With technologies like autonomous driving becoming in demand features, if people are too lazy to drive their car, they are definitely too lazy to shift for themselves, even with paddles.

But as pointed out, it's all down to the programing. That alone makes or breaks the experience. I'd even venture the guess that the R&D costs are largely due to programing, one program won't work for every single vehicle out there, which is why the same transmission in different models/brands/etc of cars result in completely different experiences/opinions.

B747VET

As I’ve said in other posts, I’ve driven quite a few high performance DCTs over the years. Most of the time they are an absolute joy to drive, even if you love manuals as I do.

So, the only real question for me pertains to the quality and tuning of the C8 DCT. The ones I’ve heard shifting, especially on tracks, leave an impression of very high quality and very fast, almost instantaneous power shifts. If the DCTs in the retail base C8s are of the same quality and have the same tuning I think Corvette is going to have a lot of very happy campers even if there is no manual. But, if the base C8 DCT is of a lower quality and/or tune than those track cars, I think Corvette is going to have some problems with sales numbers.

Bottom line, if it shifts close to those track cars, we will likely buy a C8. But, if it shifts like the C7 A8 there will simply be no C8 in our future.

sly1

I suspect that the C8's DCT will be quite similar to PDK, which offers manual shifting, automatic mode, and Sport or Sport Plus modes. Moreover, the latest generation PDK transmissions incorporate new fuel-saving modes which decouples the transmission from the engine to allow the engine to idle while coasting. So the C8 driver will likely have several options as to how he wants the DCT to shift.