The A8 transmission, difference between reality & perception
Thread Starter
Instructor
Joined: Aug 2013
Posts: 141
Likes: 3
The A8 transmission, difference between reality & perception
Hey Guys & Gals,
I have a 15 C7 A8. I am totally happy with the trans. In Drive it is totally seamless and blisteringly fast. Paddle shifting it is quick and has very very slight delay, especially when tranny goes into performance shift mode, says this on display. What I find annoying is that the first couple of years or so that the A8 has been reviewed it received accolades pretty much everywhere. Even Randy Pobst was very impressed by the A8. Well as time went on reviews are sounding more and more negative about this trans. Yes I get it that "things improve" but really? For example there is a review in I think Road and Track, latest issues the ZR1 was reviewed with guess what the A8. Reviewer stated that the A8 does not even belong even in a mini van, really? This is getting ridiculous. Makes it sound like this tranny is a total piece of crap. Surprised that GM even allowed such a terrible review / comment, unfair. In D it is every bit as fast as the PDK, yes in paddle mode in Sport and Track it is not quite as fast. PDK has the opposite strengths and weaknesses that the A8. No negative talk about it. I would take it with a grain of salt, these darn magazine reviews, such bias. I would talke Randy's opinion over these so called reviewers. Whatcha think? Ger.
I have a 15 C7 A8. I am totally happy with the trans. In Drive it is totally seamless and blisteringly fast. Paddle shifting it is quick and has very very slight delay, especially when tranny goes into performance shift mode, says this on display. What I find annoying is that the first couple of years or so that the A8 has been reviewed it received accolades pretty much everywhere. Even Randy Pobst was very impressed by the A8. Well as time went on reviews are sounding more and more negative about this trans. Yes I get it that "things improve" but really? For example there is a review in I think Road and Track, latest issues the ZR1 was reviewed with guess what the A8. Reviewer stated that the A8 does not even belong even in a mini van, really? This is getting ridiculous. Makes it sound like this tranny is a total piece of crap. Surprised that GM even allowed such a terrible review / comment, unfair. In D it is every bit as fast as the PDK, yes in paddle mode in Sport and Track it is not quite as fast. PDK has the opposite strengths and weaknesses that the A8. No negative talk about it. I would take it with a grain of salt, these darn magazine reviews, such bias. I would talke Randy's opinion over these so called reviewers. Whatcha think? Ger.
Thread Starter
Instructor
Joined: Aug 2013
Posts: 141
Likes: 3
Oh yeah. One more thing I forgotten to mention. Has anybody scientificall measure the shifts in paddle mode A8 vs dual clutch systems, pdk, etc? Just seeing a video I don't think is good enough, hard to tell. It needs to be tested in a proper scientific way. I have driving pdk with paddles and it does feel instant, time press paddle till gear is engaged, it is more of a violent, physical feel to it, bam, bam. the A8 in paddle mode does not feel as "violent" but does shift fast. I read something strange the other day from Tag Jeunther, not sure how you spell his name, something about other companies making the display appear like shift is occuring faster than it really is that GM is being honest.
Racer
Joined: Mar 2016
Posts: 273
Likes: 66
From: Murfreesboro TN
Well, my 2015 A8 broke, and is currently in the shop being repaired, with some part on backorder. So I’ll let you Know my opinion when I get it back...
Last edited by Toombs; Jul 21, 2018 at 03:20 PM.
Pro
Joined: Oct 2016
Posts: 624
Likes: 131
I have messed with the trans programming quite a bit on my 15 and have gotten it shifting incredily fast. In HP tuners you can see the shift time which mine is now consistently .10 seconds at WOT. It's very fast. That being said it is still not as fast when not at WOT and there isn't anything I can do to make it faster than I already have. Compared to a BMW DCT like the one found in the F10 M5 it is still slower.
I have also had an issue with the stator that caused very rough engagement of drive gear when cold and shifting from park. That was covered under warranty.
I'd say that overall I am happy with it. It does seem like it is not as well developed as the ZF A8 trans found in many European and Asian cars. The ZF always feels quick to shift and does it more smoothly. It will be interesting to see how the A8 in the C7 holds up over time especially with more power.
I have also had an issue with the stator that caused very rough engagement of drive gear when cold and shifting from park. That was covered under warranty.
I'd say that overall I am happy with it. It does seem like it is not as well developed as the ZF A8 trans found in many European and Asian cars. The ZF always feels quick to shift and does it more smoothly. It will be interesting to see how the A8 in the C7 holds up over time especially with more power.
Last edited by subieworx; Jul 22, 2018 at 08:40 AM.
Pro
Joined: Dec 2004
Posts: 667
Likes: 36
For example there is a review in I think Road and Track, latest issues the ZR1 was reviewed with guess what the A8. Reviewer stated that the A8 does not even belong even in a mini van, really? This is getting ridiculous.
Makes it sound like this tranny is a total piece of crap.
Surprised that GM even allowed such a terrible review / comment, unfair.
In D it is every bit as fast as the PDK, yes in paddle mode in Sport and Track it is not quite as fast. PDK has the opposite strengths and weaknesses that the A8.
Pro
Joined: Dec 2004
Posts: 667
Likes: 36
I have messed with the trans programming quite a bit on my 15 and have gotten it shifting incredily fast. In HP tuners you can see the shift time which mine is now consistently .10 seconds at WOT. It's very fast. That being said it is still not as fast when not at WOT and there isn't anything I can do to make it faster than I already have. Compared to a BMW DCT like the one found in the F10 M5 it is still slower.
I have also had an issue with the stator that caused very rough engagement of drive gear when cold and shifting from park. That was covered under warranty.
I'd say that overall I am happy with it. It does seem like it is not as well developed as the ZF A8 trans found in many European and Asian cars. The ZF always feels quick to shift and does it more smoothly. It will be interesting to see how the A8 in the C7 holds up over time especially with more power.
I have also had an issue with the stator that caused very rough engagement of drive gear when cold and shifting from park. That was covered under warranty.
I'd say that overall I am happy with it. It does seem like it is not as well developed as the ZF A8 trans found in many European and Asian cars. The ZF always feels quick to shift and does it more smoothly. It will be interesting to see how the A8 in the C7 holds up over time especially with more power.
Pro
Joined: Oct 2016
Posts: 624
Likes: 131
Nope. Not configurable. Although I have been able to change the amount of time it takes the trans to shift at lower loads/rpm which makes it feel like there is far less delay. The amount of time to initiate the shift following the click of a paddle stays the same, but the amount of time to actually change the gear is dramatically reduced.
Last edited by subieworx; Jul 23, 2018 at 08:50 AM.
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Racer
Joined: Dec 2008
Posts: 313
Likes: 24
From: NY
I quite liked my A8 Grand Sport and I think the trans is more than adequate.
But to be fair, I've spent some time in a PDK car and it's day and night.
Reviewers make money by being sensational but IMO the truth is, the A8 is just fine, but the PDK is like REALLY good.
But to be fair, I've spent some time in a PDK car and it's day and night.
Reviewers make money by being sensational but IMO the truth is, the A8 is just fine, but the PDK is like REALLY good.
Drifting
Joined: Nov 2001
Posts: 1,448
Likes: 16
From: Humble tx
It is fine as long as you aren't doing even spirited driving for more than 15 minutes. The Oil temp shoots up and mine also went into limp mode at 167 or so. Not what I thought when I bought it. I had a 15 Z and when I bought the 17 they told me they had fixed the overheating. Hah!
Racer
Joined: Dec 2008
Posts: 313
Likes: 24
From: NY
It is fine as long as you aren't doing even spirited driving for more than 15 minutes. The Oil temp shoots up and mine also went into limp mode at 167 or so. Not what I thought when I bought it. I had a 15 Z and when I bought the 17 they told me they had fixed the overheating. Hah!
Race Director
Joined: Apr 2007
Posts: 12,092
Likes: 123
From: Okiehoma
The A8 application in all GM vehicles has proven to be a wreck. They're so bent on pleasing the EPA and efficiency that it couldn't possibly function as it should. My '18 Denali 1500 shifts into speed 8 while cruising at 45 mph and will then switch to 4 cylinders, at this point the motor is turning at 1000 Rpms... and they can't figure why it shudders and shakes and why tQ converters are having trouble.
I just picked up a '15 Z06 w the 8 speed knowing full well what to expect and will have it tuned properly once powertrain warranty times out. It has 9000 miles on it and already shudders at low rpm ..
I just picked up a '15 Z06 w the 8 speed knowing full well what to expect and will have it tuned properly once powertrain warranty times out. It has 9000 miles on it and already shudders at low rpm ..
Racer
Joined: Dec 2017
Posts: 485
Likes: 71
From: Massachusetts
The A8 application in all GM vehicles has proven to be a wreck. They're so bent on pleasing the EPA and efficiency that it couldn't possibly function as it should. My '18 Denali 1500 shifts into speed 8 while cruising at 45 mph and will then switch to 4 cylinders, at this point the motor is turning at 1000 Rpms... and they can't figure why it shudders and shakes and why tQ converters are having trouble.
I just picked up a '15 Z06 w the 8 speed knowing full well what to expect and will have it tuned properly once powertrain warranty times out. It has 9000 miles on it and already shudders at low rpm ..
I just picked up a '15 Z06 w the 8 speed knowing full well what to expect and will have it tuned properly once powertrain warranty times out. It has 9000 miles on it and already shudders at low rpm ..
Some dealers are performing the fluid flush and trans reprogramming to prevent the shutter or death of the TC under the customer satisfaction program. My Z06 has 1800 miles on it and just started to shutter. Getting rid of the AFM is the meal ticket from what I’ve read.
Instructor
Joined: Dec 2017
Posts: 150
Likes: 44
From: Strathroy,Ontario Can
My buddy has a 2017 A8 vert and I have a 2019 A8 vert ,we have no shudder or issues with them and they shift as soft as a sisters kiss in normal driving and like a gattling gun WOT in performance shift mode. The paddle response is slow at part throttle and quick at WOT which is I suspect by design. The part throttle bang shift with no accumulator parts breaker we did 50 years ago is long gone and we are very pleased with the overall performance for the price point of this auto.
Drifting
Joined: Jun 2006
Posts: 1,388
Likes: 233
From: Palmer Township PA
My buddy has a 2017 A8 vert and I have a 2019 A8 vert ,we have no shudder or issues with them and they shift as soft as a sisters kiss in normal driving and like a gattling gun WOT in performance shift mode. The paddle response is slow at part throttle and quick at WOT which is I suspect by design. The part throttle bang shift with no accumulator parts breaker we did 50 years ago is long gone and we are very pleased with the overall performance for the price point of this auto.
Racer
Joined: Jun 2004
Posts: 335
Likes: 40
From: TX
[QUOTE=thrilled;1599144248]The A6 is ok.The A8 everything that I have heard about it not so much.Most people say it will shift faster shifting itself than shifting manually.It should be the other way around.[/QUOTE
The computer can outshift a man, If I wanted to shift I would think a manual trans would be the ticket.
The computer can outshift a man, If I wanted to shift I would think a manual trans would be the ticket.
Race Director
Joined: Apr 2007
Posts: 12,092
Likes: 123
From: Okiehoma
I was reading an article from one of the car rags in regards to the ZR1, and the writer, sounding like a puss, was talking about how nice it was to have the A8 on the track , the car demanded so much attention that shifting was one less thing to manage and on the track the A8 does what it's supposed to.
I always forget why why I sold my last car with a manual until I've spent an hour in my next one w a manual. I'll take the A8 with its warts until the A10 makes it into our cars.
The C7 A8 issues are popping up outside of its thresholds of purpose
I always forget why why I sold my last car with a manual until I've spent an hour in my next one w a manual. I'll take the A8 with its warts until the A10 makes it into our cars.
The C7 A8 issues are popping up outside of its thresholds of purpose