xxaarraa

I love AFM and love getting 27-28 mpg (2014 A6) while on the highway without even trying too hard. With 50-50 city-highway, I consistently get 20-21 mpg every tank (I log every tank on fuelly religiously for all my cars), which is incredible for a sports car. I think its clever and I love clever engineering.

HOWEVER (you knew there was a big however coming),

• I was growing tired of the non-linear power delivery of having AFM turned on. When on highway, I always had it in Eco, and when AFM cuts in and out, the car would feel like its stuttering. I am very sensitive to power delivery, so I probably notice it more than most people.
• I also got really tired of the sound profile - the cut over seemed abrupt in its effect on induction noise that gets transmitted to the cabin. I have added extra sound deadening inside the cabin so maybe that amplified the bad noises because of quietening down the tire roar?
• Above all else, the sound of running water aka exhaust leak from the dry sump while AFM was active was killing me. All 3 above proved to be a significant detractor from the driving experience.

So I recently got the Range AFM device with the extender and on/off switch and did a 500 mile trip with it. Wow, what a positive difference! Dry sump doesn't sound noisy anymore, power delivery is smooth and predictable and car just feels so much tighter and like it should for having a smooth V8.

I did a bunch of testing and noticed that cruising at 75 with AFM on always netted 2-2.5 MPG better than when AFM turned off. AFM does work, no doubt about that. My intent is to turn off AFM whenever I am in town / back roads, but leave it on while doing extended highway runs.

Frodo

Cool. So, with the Range AFM device installed there's no V4 mode. And when its time to allow V4 mode what do you do, remove the Range unit? Unplug it before starting the car or remove it "hot" while you're driving? Just how does all this work? TIA

NSC5

Even the newest version of the Range version will rarely cause a CEL on startup and it happened to me with my 2016 Z06 on a trip three weeks ago. It isn't a big deal because the issue (locks A8 into 4th gear due to communications error) resets with an engine restart and the CEL can be cleared with the Range module or will reset after a few restarts. I like the operation of the Range but after that event I have gone back to living with AFM and using manual shift mode (defeats AFM) when I don't want AFM. Hopefully there will be another update from Range that will get rid of this issue which is far less common than it was with the earlier Range modules.

On edit: I have never had an issue with the Range module performing as it should while driving and the issue only occurs at startup; there were a couple of other recent posts in the Z06 section about the same issue. I also used mine with the OBD-II switched extension cable which makes it very easy to avoid power drain from the module when the car isn't driven for several days.

xxaarraa

With an ODDII extender cable that comes with an on/off switch, you simply switch the Range unit on or off real-time whenever you want. Here's how I have it setup. You can see the switch off to the left of the Range unit. The other unit you see in the photo is my Vitesse throttle controller (love that too!)

sTz

With an M7 I have not noticed the AFM... and I'm only concerned about fuel when needed.

bjones7131

Corrrect me if I am wrong but I am told the Z06 does not have the AFM valves only the stingray. I posed this question a while back and all came back with no AFM valves on Z. I have a stingray and am getting a strange warble sound at 1500 rpm and am told it is either the AFM valves or the NPP valves, dealer has a new exhaust system ordered.

NSC5

My Z06 (March 2016 production) does not have the AFM exhaust sound control valves however ALL C7 LT1 and LT4 engines are AFM equipped regardless of model/package. Some photos of pre-production Z06 models showed the valves in place but I don't recall any owners stating for sure that they have them. I expect with the heat problems the AFM valves experience in the regular C7 exhaust system when used on the track that they would quickly fail in the Z06. Unfortunately the Z06 still has the AFM system, just not the sound control valves. AFM isn't as aggressive in the Z06 so it doesn't activate as often. The regular NPP valves are used to help improve the sound when NPP is active in the Z06.

tyho

I have a 2015 z51 M7 with some mods. After installing the Borla catless x-pipe my CEL was coming on with lean fuel distribution. I took the car in for a tune, which I really didn't want to do. The tuner removed the 1-4 skip shift and he also removed the AFM activation and 4 cylinder mode. I removed the NPP and the NPP actuators after installing the B&B Bullets, ARH cated middies and a Halltech carbon cai. I too wanted decent fuel mileage so I kept the car in eco mode on the highway. Now that the system has been disabled I find the driving experience better. The mileage is almost the same, the sound is consistent as is the power. I'm thinking of disconnecting and removing the AFM actuators. What fuse effects these, anyone know?

sTz

The Z06 has AFM, but does not have the AFM exhaust valves.

Goaty

I tried the Range AFM disabler and while it worked as advertised, I bought it hoping that combined with the NPP fuse pulled my A8 would sound louder and better. I was underwhelmed and returned it. The sound was marginally better, if at all.

Another major issue for me is that it resets your inspection monitors, and it took 500 miles of driving for them to be ready again. My car is not a daily driver so this is a non-starter for me.

xxaarraa

Say more about resetting inspection monitors?

Goaty

The Range site mentions that the device may cause the monitors to reset. After plugging the Range in a few times I checked the monitors and sure enough all were reset. Back it went after that.

wwshank

My 2015 Z06 has active fuel management (AFM) Not very noticeable, but I just bought a Range device and haven't plugged it in yet. So yes, the Z cars have active fuel management.

plmmd

hmm 13.8 mpg over the last 11,800 miles always in touring. Whats a highway?

Dcasole

3 year old post guys ....
Dave

phalse

yeah this is getting silly lately. youd think in exchange for all the censorship and vendor sucking that theyd at least tune the vbulletin code a bit =]

jwmgr8

When I first got my 2016 Z51 and experienced the AFM operation I bought a Range AFM elimination device. It was ok for about a week then it caused a transmission communication code. This ocurred several times a so I just unplugged it. I thought about installing an on off switch but have not. If I were Range I would have a built in timer which only allows it to come on after all post startup code checks are complete. Probably like 5 min??

Dcasole

just send it in and get the latest firmware , no problems with the latest firmware.....

Dave