Had the Phase 1 fix performed on our DSG Sportwagen yesterday. What follows are my observations so far, hopefully someone will find them useful. Generally the process was painless.
The actual software modification to the car takes all of 10 minutes for the tech to perform. The other 50-80 minutes are spent by the tech and service manager taking pictures of the car, vin, updated emissions stickers, completing paperwork (electronically), uploading all documentation to VW, printing new MPG page and restitution receipt (or I would imagine check for those not choosing the ETF). I left with that new MPG page (unchanged from original window sticker) and restitution receipt. The car left with updated software and two updated emissions stickers under the hood.
The car drives slightly different in D and almost imperceptibly different in S. By different I mean the car accelerates more smoothly, albeit slightly more slowly in D, simply more smoothly in S, and will auto-up-shift in M before the redline. These are just seat of the pants opinions but it feels as though the three main software modifications made to get it under the negotiated Gen 3 emissions standard were to the throttle response, the transmission shift-points, and the red line auto **** when the transmission is in M.
Throttle response: It feels like the ratio between accelerator pedal travel and throttle body opening has been increased. Whereas now more pedal travel is required than before to obtain a given amount of throttle body movement. So for purposes of example, imagine pre-software mod the ratio between pedal and throttle body was 2:1 now it is 3:1. This may explain the “sluggishness” and/or “smoothing” of acceleration that has been reported especially coming off a stop or when accelerating to change lanes or merge. The power still feels like it is in the engine, it just takes slightly longer to get it to the wheels. This change is most noticeable in D and somewhat noticeable in S.
Transmission shift-points: It feels like the transmission is shifting sooner and not allowing the engine to linger in higher RPMs. By sooner I’m guessing under 200 RPM sooner. So the change is not huge but it does seem to be there. Again, this also may contribute to the “sluggishness” and/or “smoothing” of acceleration since the engine does not have to dump as much energy between shifts. So the top end speed still seems to be there for all practical purposes on the highway it just takes slightly more time to get there. This difference is most noticeable in D and not really all that noticeable in S.
Red line: In M it automatically upshifts about 500 RPM before the red line. Honestly, it may have been doing this before and I just now noticed it but just in case this is a change, I’m mentioning it here. Really though, I hope I don’t need to point this out but if you’re driving the car so hard that you’re regularly hammering off of the redline in the DSG’s M mode you probably should have just learned how to drive a stick and bought a manual TDI. So, assuming this is a change I see this as having about zero practical impact.
Overall assessment: Assuming these three perceived changes are real, perhaps what they did to get the gen 3’s to the negotiated emissions standards was effectively detune the throttle and transmission to keep the engine loads lower in everyday driving, thus reducing emissions. Interesting side note, on the updated emissions sticker under the hood, manual TDI’s are allowed to put out slightly higher emissions than DSG’s. This makes sense if the above is true because no software update will be able to control the shift points of a manual so their only control over engine loads is throttle response.
Anyways, the part I’m sure everyone is curious about:
Does it feel like the same car? In D, 95% yes. In S, 98% yes, in M 99% yes.
Would we have bought it if it came off the lot with the post update performance characteristics? Yes, it still drives like a great car with a great motor. This car is my wife’s daily driver she can notice a slight difference but she’s still completely content with its performance. I drive an R daily and if this happened to my R I’d be super bummed because I use and drive that car differently than our TDI. But, for the reasons I drive the TDI, I’m perfectly happy with the results of the update. The changes are super minor in my untrained, subjective, inexpert, opinion. All in all, we think VW did a great job in putting a fix together for the gen 3s.
Are you worried about longevity, phase 2 mods? Not really, for at least two reasons. One, the extended warranty that you get with the mods is fantastic and two, we’re getting a new free DPF as part of the mods. We’ll need this because based on the changes outlined above, I’m guessing we’re getting new emissions hardware at phase 2 because the lower exhaust temps resulting from the lower engine loads during everyday driving cause the DPF to fill faster than designed due to less efficient regens resulting from the lower exhaust temps. This is seems consistent with the different mileage criteria between the DSGs and manuals (DSGs have a lower mileage criteria than manuals) for the emissions components replacement at phase 2 since manuals will generally have higher exhaust temps than DSGs after phase 1 mods because the update cannot control the shift points of the transmission.
So, that’s all I have, a bunch of personal experience, amateur guesses, and subjective opinions. These forums have been the source of a wealth of information since we bought our TDI. I hope this post contributes something back to the community.
Admittedly, I not an expert in any of this, I just know generally how cars work. I could be completely off base here so feel free to correct any errors you think you see and have fun discussing.
I’m out.