C8 problems
Melting Slicks
Joined: Dec 2006
Posts: 2,694
Likes: 106
That's true on paper, but we're probably talking a fraction of a percent better, so immesurable IMO. Modern planetary-gear transmissions lock up almost instantly, so it's practically the same as a DCT IMO. The only difference is probably their difference in weight, which is very little, for what I understand (a DCT slightly lighter, if at all). BUT they're smoother, and as I mentioned earlier, last the life of the vehicle typically without a single issue or maintenance needed (other than maybe a change of fluid). I honestly don't understand how they can do aggressive throttle-blip downshifts without clutches (like DCTs), but on the last M car I drove, they were just as aggressive as my last Porsche PDK, which are the best DCTs IMO. And the Lexus LC500 does the same.
Race Director
Joined: Aug 2016
Posts: 12,763
Likes: 10,198
From: Garden Valley CA
That's true on paper, but we're probably talking a fraction of a percent better, so immesurable IMO. Modern planetary-gear transmissions lock up almost instantly, so it's practically the same as a DCT IMO. The only difference is probably their difference in weight, which is very little, for what I understand (a DCT slightly lighter, if at all). BUT they're smoother, and as I mentioned earlier, last the life of the vehicle typically without a single issue or maintenance needed (other than maybe a change of fluid). I honestly don't understand how they can do aggressive throttle-blip downshifts without clutches (like DCTs), but on the last M car I drove, they were just as aggressive as my last Porsche PDK, which are the best DCTs IMO. And the Lexus LC500 does the same.
Dual-clutch transmissions (DCTs) are generally more fuel-efficient than automatic transmissions. Some say DCTs are about 6% more fuel-efficient than standard automatic vehicles. Others say DCTs are 3–5% more fuel-efficient than manual transmissions, which are 5–10% more efficient than automatic transmissions.
That is enough to make GM look at it closely to meet CAFE requirements. Consider how little AFM increases fuel mileage but is incorporated into the C8 Stingray.
Melting Slicks
Joined: Dec 2006
Posts: 2,694
Likes: 106
As far as packaging, which is a very valid concern, FWD vehicles (with a front trans-axle) can be found with both 8-sp regular transmissions, as well as 8-sp DCTs (like the newest Hyundai Santa Fe, for instance, which I owned a '22 DCT), so I imagine packaging shouldn't be an issue on a rear trans-axle either. But who knows. Porsches had a regular automatic transmission before DCTs, so that's another example of being possible. The problem is after spending a ton of money on development, GM is not going to turn to a regular transmission now, so that boat has sailed either way, so not worth speculating, I guess. The C8 is stuck with that DCT, whether we like it or not. So hope it at least gets reliable, with maybe a new (or revised) valve body, and hopefully less intensive maintenance requirements. But probably wishful thinking. Ha ha.
Racer
Joined: Oct 2011
Posts: 301
Likes: 117
From: Brentwood TN
According to Google AI:
Dual-clutch transmissions (DCTs) are generally more fuel-efficient than automatic transmissions. Some say DCTs are about 6% more fuel-efficient than standard automatic vehicles. Others say DCTs are 3–5% more fuel-efficient than manual transmissions, which are 5–10% more efficient than automatic transmissions.
That is enough to make GM look at it closely to meet CAFE requirements. Consider how little AFM increases fuel mileage but is incorporated into the C8 Stingray.
Dual-clutch transmissions (DCTs) are generally more fuel-efficient than automatic transmissions. Some say DCTs are about 6% more fuel-efficient than standard automatic vehicles. Others say DCTs are 3–5% more fuel-efficient than manual transmissions, which are 5–10% more efficient than automatic transmissions.
That is enough to make GM look at it closely to meet CAFE requirements. Consider how little AFM increases fuel mileage but is incorporated into the C8 Stingray.
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Racer
Joined: Oct 2011
Posts: 301
Likes: 117
From: Brentwood TN
owned three 911’s
had a C7 Z06 modded (750hp), but auto. Sold it because the auto was absolutely awful.
my last 991 PDK was pure magic
My F Type ZF8 speeds were great also.
PDK was best - until I drove this C8 DCT - I think I like it slightly better since it’s coupled with better low end torque. Would love to afford a 992 turbo PDK. But for now, loving this DCT!!!
Le Mans Master
Joined: Apr 2013
Posts: 6,671
Likes: 4,144
2020 C8 of the Year Finalist - Unmodified
A couple of times my doors wouldn't open. Not sure why. I even hit the key fob and here a click, see the dash light up, but the doors refuse to open when I pull on it. The 2 times this happened I tried 4 or 5 times before the door opened.
I wonder if sometimes the window doesn't drop to allow the door to open. Anyone else had this? Its a big worrying that you could be locked out of your own car.
Also a few times the radio just refuses to play. Have to shut the car off, let it sit several minutes, then when restarting it works again. Weird.
I wonder if sometimes the window doesn't drop to allow the door to open. Anyone else had this? Its a big worrying that you could be locked out of your own car.
Also a few times the radio just refuses to play. Have to shut the car off, let it sit several minutes, then when restarting it works again. Weird.
Melting Slicks
Joined: Feb 2006
Posts: 2,261
Likes: 1,431
From: Brentwood CA
A couple of times my doors wouldn't open. Not sure why. I even hit the key fob and here a click, see the dash light up, but the doors refuse to open when I pull on it. The 2 times this happened I tried 4 or 5 times before the door opened.
I wonder if sometimes the window doesn't drop to allow the door to open. Anyone else had this? Its a big worrying that you could be locked out of your own car.
Also a few times the radio just refuses to play. Have to shut the car off, let it sit several minutes, then when restarting it works again. Weird.
I wonder if sometimes the window doesn't drop to allow the door to open. Anyone else had this? Its a big worrying that you could be locked out of your own car.
Also a few times the radio just refuses to play. Have to shut the car off, let it sit several minutes, then when restarting it works again. Weird.
As cars now days are run by computers, they sometimes need to be "rebooted" so to speak just like many other electronic devices. I found out how to to this from this video. First, start the car. Shut the car off. Then open the drivers side door for 90 seconds (and you have to have it open for no less than 90 seconds). Close door, start the car and the computer cache has now been reset, hopefully taking care of any electronic gremlins one might be having. Watch the video using the link below at the 1:44:46 mark.
Drifting
Joined: Jan 2014
Posts: 1,618
Likes: 1,126
From: Cincinnati OH
If you haven't already tried this, you might want to give it a shot the next time it happens. I've posted this numerous times before but always good to re-post.
As cars now days are run by computers, they sometimes need to be "rebooted" so to speak just like many other electronic devices. I found out how to to this from this video. First, start the car. Shut the car off. Then open the drivers side door for 90 seconds (and you have to have it open for no less than 90 seconds). Close door, start the car and the computer cache has now been reset, hopefully taking care of any electronic gremlins one might be having. Watch the video using the link below at the 1:44:46 mark.
https://youtu.be/QgR1WMDYd1M
As cars now days are run by computers, they sometimes need to be "rebooted" so to speak just like many other electronic devices. I found out how to to this from this video. First, start the car. Shut the car off. Then open the drivers side door for 90 seconds (and you have to have it open for no less than 90 seconds). Close door, start the car and the computer cache has now been reset, hopefully taking care of any electronic gremlins one might be having. Watch the video using the link below at the 1:44:46 mark.
https://youtu.be/QgR1WMDYd1M
Racer
Joined: Nov 2021
Posts: 329
Likes: 180
From: Northwest Florida
I am sorry for your troubles, I hope they get resolved soon. These are not cheap cars. Even though we have not had such problems with ours (aside from the display turning black one time on my wife's car, which was reset by turning off the ignition and restarting, that was 6 months ago and has not come back), I would positively hate it. But so far, so good with ~30k and ~10k miles on ours.
Melting Slicks
Joined: Apr 2021
Posts: 2,756
Likes: 2,323
From: Simi Valley, CA
2022 C8 of the Year Finalist - Modified
Regarding the missing stripes, my C8 was missing the Stingray R graphics package when it was delivered (backordered) and it took a a couple of months to come in. During that time I could never get an ETA from anyone, just that it wasn't forgotten and they would let me know when it came in. I put off my ceramic coating until it arrived (in retrospect, I didn't need to do that).
About the damaged hatch, did you take delivery at MacMulkin? They have a reputation for excellent customer service so I'm surprised you're not getting any response from them. Could you elaborate on what you have done so far since you noticed it?
About the damaged hatch, did you take delivery at MacMulkin? They have a reputation for excellent customer service so I'm surprised you're not getting any response from them. Could you elaborate on what you have done so far since you noticed it?
Intermediate
Joined: Jan 2023
Posts: 39
Likes: 7
Brand new C8 2024 HTC, and the driver side seat belt is stuck completely retracted back, and will not come back, so how many have you experienced it? What’s the fix? I have an appointment with the dealer, but I was wondering if there’s a temporary fix that worked for someone here. Thanks!
Melting Slicks
Joined: Apr 2021
Posts: 2,756
Likes: 2,323
From: Simi Valley, CA
2022 C8 of the Year Finalist - Modified
I've seen this problem here on the forum before. I think most had to take it to the dealer. Google "passenger seat belt stuck on c8 corvette" and you'll find links to other discussions on the forum.
Melting Slicks
Joined: May 2021
Posts: 2,562
Likes: 1,579
Brand new C8 2024 HTC, and the driver side seat belt is stuck completely retracted back, and will not come back, so how many have you experienced it? What’s the fix? I have an appointment with the dealer, but I was wondering if there’s a temporary fix that worked for someone here. Thanks!
