Rambling and overthought post:

Wow, I've noticed several posts on various threads where owners are sensing a difference in their A8 performance and even engine performance with the Range. Its been my understanding all along that the Range simply prohibits V4 operation and has nothing to do with engine performance outside that objective and nothing at all to do with the A8.

Now I'm beginning to wonder if there's more to it than I thought. Perhaps in eliminating V4 something else is changed, perhaps inadvertently. I doubt there's transmission changing software in the Range but perhaps if you change something within the engine management software, then that software makes associated changes in the A8's performance software. Perhaps some of the high performance software is now unavailable. Perhaps the Range is spoofing some variable values to prevent V4 mode with unintended, or uncontrollable, results. We don't know how it works and it's not as simple as the Range software flipping a switch in the car's computer, as demonstrated by the Range repeatedly causing CEL and the constant upgrades needed to correct that .

I've had a Range on my '15 A8 for almost a year. Its wired in so that power is switched on at startup, so the Range is always plugged in and active. I haven't noticed any difference with it but I'm a very laid back driver so I don't experience the high performance that may or may not still be available with my car. Its been a while, and likely not since I added my Range, that I drove it hard enough to make it pop at shift time.

 

I have the Range in my 2016 Z06 and I notice no change in transmission/engine behavior other than staying out of V4 mode. The Range module works by indicating that conditions necessary to go into 4 cylinder mode are not met and it is possible that in 2017 and later years the ECM or TCM is changing its behavior based upon this data.

My 2016 has the same pop at the shift point with the Range as it does when running without it. When I first got my Range and Z06 the version out would sometimes cause a CEL at startup due to communications errors and I got in the habit of driving it in manual often but for maximum acceleration I would put it in auto to take advantage of the 8L90 shifting more precisely than I could. With the Range active and in auto mode full throttle shifting is the same as with no Range and auto mode.

You might want to pose this question to Range at their website.

 

I don't typically drive aggressive enough to comment on the performance aspect of Range use, but I have noticed an anomaly that may indicate more than just preventing V4 is going on there.

When the Range is operating, the instant MPG on the DIC never indicates 99 MPG (which I assume means fuel to the engine has been shut off during deceleration). With the Range off and operating normally in either V4 or V8 mode I frequently see 99 MPG when off throttle going down hill or decelerating. Go figure!

 

No issues at all on my '16 model. Works just as it did other than V4

 

 

Any time you try to 'spoof' the ECM especially thru the OBDII port there is no telling what kind of strange behavioral results that can take place.
But if you actually change the tune to turn off the DOD/AFM inside the ECM then these undesirable artifacts will not take place.
Diablo I3 is the best solution.

 

 

Only if you're out of warranty and don't have an extended warranty.

 

I hardly use the Range at all anymore, but when I do, I haven't noticed any shifting or Performance difference.
As for anomalies, I have a switch on mine since it's an old 7.4 Version.
I turn it on after the car is running and all systems are booted up.
Never have a problem with it that way, but experimented a few times shutting it off and on while driving.
And the only thing I notice when shutting off the Range while driving, is it takes about 3 minutes before the car starts switching between V4/V8.
I may be wrong, but that's telling me it takes a while before the affects of the Range clear the system, after its turned off.