A photo of the test equipment from the WVU report. I remember when VW was getting to release the CR equipped cars ( my Jetta had a PD engine) VW said they could get away with not using SCR in the Jetta and Golf 'cause they were under a weight limit to need it. They used SCR in the Passat because it was heavier. I would imagine that now, it would be easier to correct the problem with the Passat than with the Jetta/Golf system.
From GreencarCongress: Green Car Congress: EPA and California ARB charge Volkswagen with using software defeat device to circumvent NOx testing in 4-cylinder 2.0L diesels To have a more controlled evaluation of the high NOx observed over the road, CARB developed a special dynamometer cycle which consisted of driving the Phase 2 portion of the FTP repeatedly. This special cycle revealed that VW’s recall calibration did increase Diesel Exhaust Fluid (DEF) dosing upon initial startup; however, dosing was not sufficient to keep NOx emission levels from rising throughout the cycle. This resulted in uncontrolled NOx emission despite the SCR reaching sufficient operating temperatures.  Makes sense as catalytic converters use HCs to scrub the NOx and NOx to scrub the HCs. The Prius does this by oscillating between a rich and lean mixture so the catalytic converter can neutralize both. Link to the original ICCT announcement and download link: In-use emissions testing of light-duty diesel vehicles in the U.S. | International Council on Clean Transportation Bob Wilson
Being a VW probably because they were bypassing the emissions The modern Euro 6 diesels (from 2014 onwards - some earlier) we get here don't spew smoke at all and the inside of the tail pipe will be totally clean. You really have to see it to believe it. BUT it's the invisible NOx that's the baddie.
This is probably not new. VW probably mastered it in European emission test. It is very difficult to be clean, efficient and fun to drive. I think Gen4 Prius is going to be a hit.
So I added a comment to "Meet the Volkswagens - Jetta TDI Meets Prius" "The cough was from the NOx pollution from the VWs." Bob Wilson
I remember the performance comparison video and the video of the TDIs with coffee filters, but I don't recall an emissions comparison video.
Something perhaps to add to the gall of all this is the fact that some of those cheater "clean" diesels (MY 2009 and 2010) qualified for federal tax credits. The sum I've been reading is $1300.
Exactly this. They got away with it in Europe because the Germans aren't going to attack their largest car manufacturer. Someone decided to bring their diesel offerings to the US as the newer EU models complied with US emissions, without realising the dodgy hack in the software? That would make more sense. They took the EU emissions at face value. As you guys would say "that'll learn 'em"
The same study that prompted the EPA/CARB investigation (ICCT/WVU) found that all other regulated emissions were well below regulated levels in the "multi-state" test, including PM... (Page 83 - Thompson et al., "In-Use Emissions Testing of Light-Duty Diesel Vehicles in the United States." International Council on Clean Transportation Report, May 15, 2014)
Based upon the ICCT.ORG report: Vehicle A and Vehicle B have the same 2.0 L diesel. Vehicle B has the urea-SCR system. I do not see an easy fix since the report pointed out the NOx problem got worse as the test durations increased. In effect, the 2.0 L vehicle can handle a short, test duration but it gets worse as the test duration increases. From the report: Vehicle A and B are outfitted with the same engine model. However, they also feature different after-treatment systems allowing to conclude, based on the available data, that the LNT shows deficiencies over the urea-SCR system in efficiently reducing NOx in-use, especially during highly transient, low-speed urban driving as well as high-load uphill driving. On the other hand, Vehicles B and C are both equipped with a similar after-treatment technology, namely urea-SCR, but show significantly different NOx emissions factors for the same test routes. This could be caused by i) different after-treatment control strategies, ii) a difference in catalytic substrate between the two vehicles (different SCR type), iii) under-sized SCR catalyst for Vehicle B, or iv) different diesel exhaust fluid (DEF) injection strategy in case of Vehicle B to reduce DEF consumption, hence, increasing DEF re-filling intervals. This is bad . . . very, very bad. Bob Wilson
I believe VW will be forced to get into more HEV/PHEV/BEV, to avoid this embarassing "issue"... VW accused of using 'defeat device' software in 482,000 diesels to skirt U.S. clean-air rules
The letter and cliff notes versions I linked to at VW Faces $17B Fine for Emissions Scam | Page 2 | PriusChat basically says the same thing. (Not sure how my text there got doubled/repeated...)
And thank God for CARB! Anyone living in California back in the 1950s and 1960s remembers the ever-present brown haze over L.A. and surrounds, and the eye stinging, physical-activity-limiting effects of auto emissions. So, I for one, applaud CARB for its leadership in getting vehicle emissions cleaned up. And I hope they continue raising the bar, and the slower states to finally reach the 21st century. The US doesn't need law-avoiding, unethical corporate entities.
To add on to GC's post, the black stuff on the inside of the Prius tailpipe is from particulates; soot is just a different name. Diesels with working DPF, and the car still might puff once in awhile, still have clean tailpipes after thousands of miles. Going to get rid of them all then.
No problem. Do you want to tell the several hundred thousand people that will lose their jobs that VW/Audi/Bentley etc. has been kicked out of the country?
The same thing I teach young healthcare professionals: if your employer asks you to do something illegal or even unethical, your professional duty (if you can't change the employer's policies and practices) is to LEAVE. Those working for slimeball corporations? I realize the employees didn't do this, but that doesn't change the facts. Maybe the offender should be divested of those American factories and someone that obeys the law and has a modicum of ethics could take the batter's box.
Keep it in perspective. Only the 2.0 L, TDI diesels. No known problems with their gas powered cars. Bob Wilson
Although they need a lot of work in the product reliability department, I would hardly call VW slimeball. Ford, GM and Chrysler on the other hand... Never mind, just saw your Bio. Wasted time responding.