TypingAllDay

Interesting note - I brought our 2012 A8 4.2L in for an intermittent no-start condition after engine reaches full operating temp. Most forums pointed towards the high-pressure fuel pumps (HPFP), however the dealer said this was a known issue & there's a software upgrade that fixes it.

Fast forward to me hitting a regular freeway onramp for the first time... At wide-open throttle, my butt dyno (and my wife's) definitely noticed some improvement. I'd say ~ 5% more pull? The engine also seems to *sound* more aggressive while accelerating. Also unsure if they flashed the transmission, but shifts seem to be better matched to RPM / desired acceleration in dynamic mode.

So - nothing too crazy, but those of us with 4.2L non-diesel motors may benefit from new software.

A8L_New_England

.
Maybe they optimized the tune a bit to encourage people to bring their car in for service more often
.

TypingAllDay

Would not surprise me in the least!

2001 S8

Very interesting. What is the software upgrade called/coded as? I'm heading into the dealer in July to replace the Camshaft Sensors and update the software.

Thanks TypingAllDay

TypingAllDay

It was software related to TSB# 2035617/2 according to my invoice (which wasn't actually the problem I was having, so we'll see if that comes back...)

2001 S8

Thanks TypingAllDay. This is very helpful. Hope all is well with your 4.2 now.

MP4.2+6.0

Hate to throw cold water on it, but...

More likely, post flash it is running its adaptation routine. When you reset the ECU--which happens with a flash IIRC--it resets its adaptive learning.. Thus throttle tip in, general agressiveness, etc. Now all learned anew, and any imprints of a prior driver or his/her style are gone too. At least on D3, you could trigger this for both ECU and TCU separately.

Via VCDS to be clear, not the old Audi wive's tales about manipulating ignition, gas pedal and twirling around three times stuff. Not sure exactly how the ECU outputs to TCU affect changes in shifting, or if solely controlled by TCU.

TypingAllDay

I had considered that after having gone through several flashes with a previous car, however the freeway onramp thing happened at least 150 miles since I picked the car up & I assume adaptive learning had already occurred. Moreover, I don't think WOT would be more aggressive throughout the power band from adaptations - vs. say low-end / general throttle response.

Would have loved to do a before/after dyno!

MP4.2+6.0

Trouble with any theory that it actually increased power is that the manufacturer almost invariably would have needed new EPA and CARB approvals and a whole certification run and expense. Play with any of mixture, ignition or valve timing, and EGR function and its going to affect emissions; so could even coolant temp. Shift points can affect MPG ratings. Audi has been busted for MPG occasionally, including on D4/4.0T IIRC. In practice, typically only happens the other way w/ maybe some power or MPG loss they really try to avoid--where they get busted for an emissions issue and then have to recertify and recall. Dieselgate is of course the all time poster child for it.

TypingAllDay

The car feels noticeably faster throughout the power band. Not sure a software patch that improves efficiency would require EPA / CARB approvals, but sounds like you have some expertise on this topic.

¯\_(ツ)_/¯