[rlonstein]

> No. They cheated to pass the exam on the cheap, instead of investing in the required R&D to create a motor that gives out the same amount of power while reducing emissions.

I'm not going to apologize for them but I can concoct how it happened... I think it all stems from the termination of the licensing deal on Daimler's BlueTec system/standard. Until 2007 VW used the BlueTec system but probably didn't want to continue paying license fees, track a moving target under a competitor's control, and support a competitor's branding alongside their own TDI branding. Continuing my guesswork, they expected their engineers could work out a replacement system but it proved harder than thought when tested in actual driving conditions. Speculating even more, someone noticed that under certain conditions the TDI engines performed up to the standard so they programmed the ECU to do that. But other performance metrics and reliability sucked. It was going to take time to work it out but the model year doesn't wait. Wild-assed guessing and getting into intent, someone down low in the hierarchy realized you could detect an emissions test (OBD2 port in use, wheel sensors differ, speed and rpm and timing, etc.) and trigger the clean mode. Unless someone stuck a sensor up the tailpipe while the vehicle was actually moving, no one would know and there would be enough time to work out the actual emissions problems. Except the vehicles were selling and maybe someone a little higher up decided not to fix it at all.