[OPINIONS] Post-Emissions Modification on Gen1 TDIs

For Gen1 TDI owners opting for an emissions modification vs buyback, work can begin at your respective local dealership as soon as tomorrow (11-Aug-17). The reported effects will be as follows:

1. Increased engine noise
2. Difference in engine operating modes
3. Change in torque between operating modes
4. Decreased fuel efficiency (up to 2MPG)

Personally, Items 1 and 3 concern me most. If you're one of the first to proceed with the modification, please share your post-fix opinion on all points above. There are surely a few of us anxious to go, but weary of the effects. :yikes: Once you have the modification applied to your vehicle, there's no going back: your buyback option ceases to exist even if you're unsatisfied with how the modification affected your vehicle.

For those in California, I'm already hearing rumor from at least one owner (albeit via dealer) about DMV suspending registration renewal pending proof of modification being applied, essentially giving no choice but to have the modification applied if you ever want to drive the vehicle legally in the state again.

Good luck everyone. Look forward to hearing your opinions and experiences.

I'm a 2.5 owner but I've been following this diesel scandal form the start, more from a technical point of view.

Sounds like all the DMV is looking for is a paper showing that the fix was applied. There are very few places in the US that can do diesel emissions testing to prove or disprove the fix. Get your paper and see how things go, but most likely the milage will be less but chances performance will be the same.

I recently read a Car and Driver article where they tested a few of the TDIs with the retrofit and Car and Driver reports that the performance is on par with post fix expectations. As a student of ECU Tuning I can tell you that this is entirely probable with diesel engines, following the retrofit all VW has to do is to bump the boost and the torque limiters to meet the post retrofit performance. This would be similar to what Diesel Tuners would do to increase performance.

I hope this helps, good luck and enjoy your car !

Thanks MLue1. I/we remain hopefully optimistic to results as you describe. A 2MPG loss would manageable, but I don't want any loss of power, torque, ... feel. Increased engine noise would be a less-than-desirable effect too. Proof will come with the first few cars. Awaiting sharing of first-hand experiences.

UPDATE: Pulled trigger on main emissions modification yesterday (including snow-flap replacement). Afterward, topped off tank to monitor/assess true MPG effect over next few weeks. Otherwise, absolutely no discernible effects (noise or performance) observed. Cool!