docprego

On another forum a user has raised an interesting question: "Is AFM only active in ECO mode on the 2016 C7?"

He provides this quote from GM's 2016 press release as evidence:
"Active Fuel Management: in normal mode, the LT1 engine uses V-8 power; in Eco mode the engine can operate in V-4 mode to improve fuel economy until aggressive acceleration is called for"

I've read this press release many times, but I have to admit he got me thinking. This line does not mention anything about being related to a specific transmission. It's simply about the driving mode in this statement. Has AFM become a mode based feature and no longer dependent on the transmission you have?

So anyone with a '16 and an A8, can you get to the bottom of this? Does the owner's manual make any mention of it?

Needless to say this would be a terrific improvement for '16!

C8Jake

M7 ECO...7th gear only
100% useless feature to boost CAFE

Kev4

Agree, only required to meet EPA mileage figures.

Deicide

If true, would be great if '14 & '15 A6/A8 could have the programming updated to support this as well.

owc6

And avoid the gas-guzzler tax!

Deicide

I'd pay a retroactive tax just to get rid of it unless in ECO mode.

TorqueDriver

That would be outstanding if for 2016 the AFM would only be active in ECO mode for both the manual & A8 transmission!

Maybe someone here with more inside technical knowledge could fill us in.

owc6

It would be nice to disable it in D. It doesn't really affect me, because I only drive in M, but I might drive in D if it wouldn't come on.

Steve_R

Mine hasn't been out of Sport mode since I bought it over a year ago and I use the paddles so it's never seen V4 mode.

themonk

isn't there a fuse pull to nullify it?

docprego

No. Requires tuning it out or the AFM disabler device.

We need someone with a 2016 A8 to test this out for us.

fmcooper

I don't think this is accurate -- pretty sure I was seeing V4 mode yesterday in 5th and 6th gear. I was bored and on a long cruise watching my MPG go up. You definitely have to be in ECO mode.

Ernest_T

Meh...I like AFM when I'm just driving down the highway. I keep my mode selector in sport mode all the time and I see V4 about 75% of time on the instrument cluster. About the only time it doesn't go into V4 is under acceleration or a long, up hill climb.

Babaron

I am quite certain there has been no change from the 15's to the 16's. Otherweise, it would have had to undergo repeat testing by the EPA. So, it is active always in Auto's except during paddle shifting, and active ONLY in ECO mode with Manuals.

What really bugs me is the fact that they still got hit with a GG tax on the A8 Z06 even with the infamous AFM. Should have just scrapped it and let A8 owners use it optionally even in drive. (in hindsight.)

Jim Barker

I agree 1000% only should activate in eco mode like the manual cars!

10mm_

That makes no sense because they did't use the Eco fuel number in the published fuel mileage rating, they used the Touring number.

DAFFYDRUNK

I also doubt they changed the way the A8 works for '16. Too expensive to retest AFM activation in eco only which would surely result in a lower number for the A8.

As for my 15, my AFM kicks in in eco mode in pretty much any cruising gear. I use eco all the time if I'm highway driving. Might as well get good gas mileage. I wish there was some way to completely disable all but super quiet exhaust mode in eco. Coming out of AFM is mildly irritating to me. Wish it would just stay dead quiet all the time in eco. Maybe there's a setting I can tweak?

scottsh

Are you sure? I ask because I wasn't aware there was any way to keep the A8 from going to V4 mode when it wants - neither the use of paddles, M (vs D) shifter setting, or any driving mode?

Ernest_T

Using manual mode and manually shifting with the paddles is the only way to totally disable AFM in an auto transmission Stingray. You could also do it by frequently shifting gears with the paddles while in drive mode, but it'd be hard to keep it out of V4 because the transmission reverts to normal auto operation after a few seconds with no input from the paddles.

I'd like to know if Steve_R manually shifts his A8 all of the time.

vettekat2007

I was searching for the excellent write-up which summarized all these settings the other day and I could not find it. I believe it was posted some time ago by either THETA or ZYMURGY and I thought it was a STICKY but I could not find it anywhere when I searched. Anyone have the link? Thanks.