Mad Dog 24

On a long trip the V8 to V4 Eco modes stopped working on my 2015 Z06. It now stays in V8 only. I tried shutting it off turning to Sport, Tour and nothing helps. I'm in the middle of a 2k ride and would like to use it.

Any ideas to reset, I rather not waste a day at a dealer I don't know?

VETJAZZ

I'm anxious to hear replies. My 14 A6 wouldn't go into V4 on a 35 mile trip across town the other day, but it worked normally on the way home.

GizmoZ

Automatic or manual? I believe with the manual it only works in Eco mode. With the automatic it won't go into V4 mode if you're using the paddle shifters.

JoesC5

Several of us went on a 3400 mile trip and one was a Z06 A8. He said the only time it went into V4 mode was when he was going downhill, not during steady cruising on the Interstate. Very little did he see the V4 mode. He averaged 24.0 for the trip which included 80+ MPH Interstate driving, driving in the mountains in south/southwest Colorado, slow speed cruising in eight National Parks, etc. Ambient temps between 43 and 105 degrees. A little of everything.

Mad Dog 24

M7, Noticed it wasn't working while running 75 to 85 on fairly flat FL interstates. It seemed before that up north it would go in and out from v8 to v4 constantly. I was using 7th a lot which made it chug a bit when passing when it was working.

I averaged 22.6 MPG with an average speed of 57. Not bad for 650 HP!

Still hoping for an easy fix idea here.....

HolyRoller

^^ 75-85mph? No wonder you don't see V4. It needs all 8 to go that fast. Try slowing down to 45-55mph, as distasteful as that is, on level ground or downhill. Remember, it has to be in Eco mode. I suspect that if AFM really developed a problem, you'd see a check engine light or a DIC message.

eboggs_jkvl

I switch into V4 at 70 -80. I have the A6. If he has the M7, he needs to be in ECO and it will switch per the load on the engine. 45-55? Not sure about having to drive that slow to get it to switch. The V4 will switch at higher speeds than that.


Elmer

DAFFYDRUNK

Dunno... My can go into v4 at 80. Depends on the conditions. As already said, Make sure you're in eco mode, otherwise you don't get V4.

billbadal

My 2016 Z51 will revert to V4 as expected but for all drive settings, except of course track mode. I expected this would only work in ECO mode. Huh

DAFFYDRUNK

V4 mode in Eco only is just for the manual 7 speed cars. In the Autos, it can go into V4 in other modes too.

rmorin1249

My A8 base goes into V4 even around town at 35 mph as well as on the interstates anywhere between 60 and 80 mph as long as the road is level or downhill.

NSC5

The Z06 behaves differently than the regular Stingray since it has additional drag from the wider tires and body and additional aero drag coupled with a lower compression engine. The LT-4 has lower compression than the LT-1 so in light throttle operation when the supercharger is bypassed the LT-1 can produce more power; once boost is commanded that of course changes but it won't be in V-4 mode then. The LT-4 won't be operating in V-4 mode under the same conditions that would allow the LT-1 to enter that mode.

These body and engine differences are of course reflected in the very different MPG capabilities of the two vehicles.

Nice Ride

I have an A8 so I guess the car adjust to Eco on it's own from time to time. Probably the only way the Eco mode will ever get used used. Certainly as long I own the car

meyerweb

On level ground at steady speed, it probably doesn't take more the 40 or 50 hp to maintain 80 mph.

Mike Mercury

if it helps any... on my automatic it is easy to see the 4 cyl mode with the cruise control engaged.

Without CC... I seem to not keep steady enough on the accelerator; it's difficult to get into 4 cyl mode, and can't keep it there for very long.

Mad Dog 24

Yes of course I had it in ECO mode as that is the only way it will engage with the M7 car. I do use cruise a lot and my wife hates me driving by buttons in traffic but that could be the issue. I agree you would think if the system has failed there would be a light on. There is no engine light on and never has been.

Many miles going back home to play with it again I guess.

HolyRoller

Well, let's say the LT4 THINKS it needs all 8 to keep a Z06 going that fast. On the interstate with cruise set to 75 or so, I rarely see V4. Doing only 55-65 on deer-infested rural roads at night, V4 is more common. I skipped right over the Stingray stage so YMMV, literally, with the LT1.

eboggs_jkvl

Well, if this was in the Z06 forum, maybe some one would know the information and share it. If the LT4 acts different than the LT1 in the V4/V8 mode, maybe this thread belongs in the Z06 forum?



Elmer

Daisuke149

7th gear on the m7 is a joke. it was put in for EPA results where they could test it in a perfect flat bed at a certain speed. The software is jacked, anytime you push the throttle past 4% it seems it kicks down to v8. You stay in v4 longer in 6th gear cruising, but i'd rather cruise at 1100 rpm with 8, than 2000 rpm with 4.

They really should force v4 more in 7th gear.

Rd16rr

other than switching to Eco Mode....how do you know the engine is using only 4 cylinders ? is there another indication/symbol ?

i thought A8's go to 4 cylinders in Touring Mode (on its own, no need to switch modes) as well, when you are light on the throttle....correct ?