The "issues" or complaints appear to be purely software related. The SRT had an annoying down shift lurching thing for a while when slowing down for a red light or stop sign...jeep produced a software upgrade/update and it's like a totally different machine. I truly hope GM provides a software update for the A6/A8 cars. You should have INSTANT power when you lean on the gas.

If this doesn't get resolved over the next couple months, I'll get the M7.


this is what i feel everytime i slow down or come to a stop . like the the car gears down .
i aslo noticed when the nanies or off you couldn't notice it as much.

 

Absolutley! Do people think the more gears the better in a performance car. When I use my paddle shifters on the highway I have to downshift four times in order to get to fourth gear power. When I accelerate at a moderate pace the car shifts 7 times. That's not cool. Maybe there is too much talk about quick shifts and not enough about how many speeds are necessary. Maybe the eight speeds are to avoid the gas guzzler tax.

 

I had same issue, believe its the 4-8 cyl lag, I always "paddle down" two gears if I need some instant push.

 

Yes that is what I feel too.

My bigger concern is when the hesitation becomes longer. It does not happen all the time and when it does; it happens at full throttle from about a 40mph roll or above when you need to quickly accelerate.

In regard to some of the other replies. Those of us who experience a hesitation are indeed feeling something that needs to be corrected. If you have a C7 with the A6 or A8 and do not have this problem be very thankful.

Those of us that do feel the hesitation need to think twice before
using the cars power to pass another car, avoid something and need to have some "extra room" just in case we want to use the power.

This does not make for a pleasant driving experience. I never had to worry about passing anything with my C6.

We should not have to manually downshift/upshift or change anything in order for the car to perform as designed after all the A6 & A8 are still slush boxes (automatics, press the gas, hang on & go)

 

had enough yesterday . this is just crazy having a car that i hate to drive . took it to the auto parts store yesterday and 4-8 4-8 all the way there .the auto would up-shift down shift ex. would go from loud to quite off and on . from what i've seen so far this car shoud have had a 4c. in it only.
called the s. mgr. and talked to him he said as much as he hated to say it the car sounds like it is op. as gm designed it . that they made it that way to save on wear on the clutch in the trans. i told him i would bring it in thur.
as far as trying to pass its like the car dosen't know what to do .
and its a car that i will never trust . the only thing that i have noticed is if you can hold the rpms at around 3k your ok when you give it gas ,but try and hold it at 3k. to much bs on this car.
was waitting on a friend yesterday parked put it in gear and had the window down motor running , i start hearing a beep beep beep outside the car , thought it was a truck some where backing up . my friend came out and said why is your car beeping ? sure enough it was the car . comming from underneath after i had put it in park.

just waittihg to hear about the first vette to have a head on because of this lag when trying to pass .........gm. you are trying to make a ''super car '' on the cheap. how many do you know with a 4-8 setup
stick with what you know ....the evo

 

[QUOTE=............. just waittihg to hear about the first vette to have a head on because of this lag when trying to pass .........gm. you are trying to make a ''super car '' on the cheap. how many do you know with a 4-8 setup
stick with what you know ....the evo[/QUOTE]



The "head on" comment is scary. Another member recently posted about a similar situation, i.e., hanging out there, passing a line of cars/trucks, slow throttle response. Is this Car too "complicated" to properly/safely drive? Looking to buy in a few MYs. But, I need to hear about more driving "experiences" when these motors have more miles on them.

 

On the HP Tuners web site in the forum discussion, there is a 15 file for the A8 but as of yet no manual file. The auto file does show a reduction in the amount of throttle apply needed to kick it out of V4. 50% down to 40%. With the extra gears its hard to say why they did it, so I am waiting to find manual tables with the same change to confirm they are tweaking the programming perimeters.
When mine is acting up stuck in V4, a downshift would certainly help to cut down on this lugging. Also instant mileage is below 10 mpg as soon as it goes to V8 it jumps about 3 mpg

 

I read this stuff and I wonder if I'm not being sensitive enough or I'm not seeing this delay problem with my A6. Mine seems to kick up & down between V4 & V8 seamlessly. And when I want to pass it just pops up & goes. Now, just so you guys know I only have 5300 miles on my Stingray but I've also driven it up to PA and back via Ocean City MD to South West Florida. Plus taken it down the local drag strip for 6 runs as well. I wonder if the A6 & A8 in the 14/15 Stingrays have adaptive software that changes in time to the driver's driving habits like my C6 did. By the time I traded in my C6 the A6 in that car was totally different from the way it ran when I first got it. Or maybe, and probably most likely, it's a tuning glitch in the trans that GM needs to hone up.

 

Do you have NPP?

 

I've noticed a bit of a "lag" in throttle response in the 40/50 MPH range with my 2015 A8. I notice much more, the coast down lag in downshifting in D for normal traffic. For example getting off the freeway straight off ramp: 65/70 MPH - When you let off gas for coast down, car appears to coast well (not much drag) until about 50, then you feel the tranny hang in what ever gear its downshifted to, not unlike light braking. If you even touch the gas the car jerks pretty hard, lags like running out of gas, then lurches forward pretty hard - doesn't happen ALL the time, but enough to be annoying. If I'm on a long off ramp, I've started to just use the paddles off and on. I figure maybe a software glitch in the A8 tranny or as many above have mentioned an AFM problem that I hadn't really considered till reading this thread. (Only 1500 miles on the car with hardly any "spirited" driving) I plan on mentioning to dealer at oil change before putting car away for winter.

 

With all due respect to everyone's comments relating to the A8, this is a smart transmission, and adapts to drivers behavior's. There is a Technical Bullentin that has been issued, that clears this up. The A8 is a well engineering system. The tranny will adapt, and the shifts will be quick & crisp across the rpm band.

 

The dealer told me to quit driving mine so much in eco mode. Now in touring mode most of the time it has been mixing things up abit but still not right. I had my worse episode the other day and it almost felt like it was going to quit it took so long to respond to throttle. Again this is light pedal driving! About 30 mph when slowly applying throttle.

 

Jim I do have NPP and I drive 90% of the time in Sport Mode.

 

With the A6, I now accept the fact that I must do a quick downshift to eliminate all lag problems .. it has become second nature at this point and I can easily live with it as is.

What doesn't sit well is that I took the car in for service today getting ready to put it in storage (new england) .. and explained the lag problem and the problem of shifting to the manual mode to keep it in 5th before tromping on the gas (and nothing happens. the engine just lugs) ...

They verified my concern .. and then stated "no problems found", "Normal Function" .... the C7 engineering team did an absolutely terrific job on this car ... no detail too small to consider ... so I can't imagine that the C7 design team would consider this "normal function".

As I said, I can easily live with the situation as is ... but I'll bet in the future the software folks come up with a fix.

charlie

 

Sorry you are having these problems AND thank you for posting about them. The auto with AFM is probably the biggest fear I have about the C7. And for the folks that will comment, an M7 is out of the question.

 

Just picked up my 2015 Z51 A8 coupe today. Didn't get to put many miles on it but did notice that driving in ECO mode about 45 with very slight throttle pressure the engine would occasionally rev to about 4k rpm. There was no sense of gear change just like it came out of gear momentarily. Switched to Touring and didn't happen again but very few miles. Anyone else experience this?

 

Hi Mike

Since we both come from a racing backgorund I would think that our driving styles are somewhat similar. While I am not aggressive I am not afraid to utilize the power

It is not adaptive, and I don't think at it is the A6 but the tune. You should be thankful that you car is fine as I never know when mine will fly or backfire & hesitate

Oh and btw I have NPP I wonder if the stock tune for NPP is a factor ?

 

I am considering the new 8 speed automatic (currently own a 13 1Lt auto) when I decide to go to the C7....are you always in cylinder deactivation mode in all driving modes or only in ECO mode? Is it cancelled when driving in Tour, Sport and Track modes?

 

My A6 C7 will engage cylinder deactivation in all driving modes. I used to experience a lag upon flooring the gas pedal. I learned from another fellow Corvette forum member that all I had to do was turn off the traction control and now there is no more lag and it goes to full v8 power instantaneously when passing another vehicle at full throttle.

 

got the car back from ser. no updates , trans op. as designed ..down
shift 4-5 times .4-8 c. on off on off op. designed ect ect ect ,,lag normal .............only thing i can say is gm says everythings ok ''sure''
on one hand glad nothings wrong on the other ...... back to driving this whatever on wheels .but you live you learn ,if anything it saved me from buying the z as i had planed . and as a long time vette owner my last till they get thier act together .best of luck to everyone else with thier probs. but looks like were stuck with these trans probs.