mungodrums

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.

mungodrums

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.

Toombs

subieworx

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.

Gadfly

Nothing about the paddle shifting is quick, and nothing about the delay in paddle response is "slight"; honestly my 2015 Hyundai 8 speed auto shifted faster and had far better paddle response than this A8. It is easily the worst paddle shifted auto sold on any performance car today.





I agree with them, this A8 is best suited to truck and min-van duty.


Because it is.

Because they don't get to sensor the truth.

No, it really isn't, sure it might get close during WOT up shifts, but that is it. The paddle performance and down shifts are freaking terrible and you don't need to look to the PDK or other high end DCT's for the A8 to be completely out classed; there are plenty of other automatics that really show up the GM A8, the 8 speed auto in my wife's SUV is faster, up and down in drive, and the paddle response is pretty much instant in both directions. Th GM A8 is just bad, all the way around bad.

Gadfly

Have you been able to do anything with the paddle response times?

subieworx

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.

rfgoss1

Has anyone heard of a tune that helps with the overheating? Also, the way the Tq Converter behaves seems like it doesn't want to let go sometimes at lower speeds.
Randy

KC2GIW

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.

rfgoss1

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!

KC2GIW

Our opinions may have something to do with our latitudes, to be fair.

rfgoss1

Very possible.

Donuts

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 ..

Silvah Goat

I had a 1500 6.2 Denali, don’t forget you can make a sandwich in between shifts. Full power to 5400, then switches to the hp of a Neon, gets to 5800, feels like it closes the throttle, shifts, slowly ads power back. It was so frustrating.

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.

David Gordon

Sounds like everyone thinking a 60k car should shift like a Lamborghini or Porsche, Mine feels good enough for what it is. I had a BMW 335is that shifted way faster but so what! My A-8 shifts fine.

marsheng

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.

Oh4GTO

I'll second this.

thrilled

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.

David Gordon

[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.

Donuts

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