# Just how did VW the cheat come to light? **URL:** \ **Category:** Factual Questions\ **Created:** [September 23, 2015, 3:41pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304 "2015-09-23T15:41:10Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![MikeF](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@MikeF](https://boards.straightdope.com/u/MikeF)\ **Post date:** [September 23, 2015, 3:41pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/1 "2015-09-23T15:41:10Z")
Maybe I missed it but I haven’t seen anywhere who figured out what Das Auto was up to. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [September 23, 2015, 3:49pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/2 "2015-09-23T15:49:45Z")
Several news sources have the detail: > [@](#): > > German and his group were actually trying to prove exactly what Volkswagen has been claiming for years: that diesel is clean. They asked West Virginia University for help. The school’s Center for Alternative Fuels, Engines and Emissions had the right equipment – a portable emission measurement system to stick in the car trunk, attached to a probe to shove up the exhaust pipe. German’s group, funded mostly by foundations, didn’t. > > Testers drove the monitor-equipped diesels from San Diego to Seattle because if Volkswagen had gamed the emission test, they couldn’t be sure how, German said. In another cheating case years ago, he said, long-haul trucks were equipped with devices that allowed the engines to gradually discharge more and more harmful nitrogen oxides the longer the vehicle cruised at the same speed. The more emissions, generally speaking, the greater the engine power. The 1,300-mile trip under varying conditions would expose any such scheme in the VWs, German said. > Meanwhile, the California Air Resources Board tested the vehicles in their laboratories and they passed. > > [Bloomberg - Are you a robot?](http://www.bloomberg.com/news/articles/2015-09-19/volkswagen-emissions-cheating-found-by-curious-clean-air-group) For cars, the benefit is/was improved fuel figures, rather than increased torque. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [September 23, 2015, 3:50pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/3 "2015-09-23T15:50:40Z")
[Just read the CARB letter](http://www.arb.ca.gov/newsrel/in_use_compliance_letter.htm) and the [EPA’s Notice of Violation.](http://www3.epa.gov/otaq/cert/documents/vw-nov-caa-09-18-15.pdf) ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [September 23, 2015, 3:57pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/4 "2015-09-23T15:57:17Z")
Here’s a good article from the NY Times on it: [It Took E.P.A. Pressure to Get VW to Admit Fault](http://www.nytimes.com/2015/09/22/business/it-took-epa-pressure-to-get-vw-to-admit-fault.html) > [@](#): > > Even with the looming punishment, the company almost got away with it. In fact, it most likely would have if not for a strange twist of fate and the curiosity of several auto researchers. > > Two years ago, the International Council on Clean Transportation, a nonprofit environmental group staffed by a number of former E.P.A. officials, had been testing the real-world performance of so-called clean diesel cars in Europe, and were less than impressed with the emissions results. > > The group decided it would test diesel-powered cars in the United States, where regulations were much more strict, as a way of almost shaming the European automakers to tighten their compliance. The group fully expected the American cars to do well, and run cleaner than their counterparts across the pond. > > What they could not have foreseen was that they would stumble onto one of the biggest frauds in recent automotive history. > > Further, on the campus of West Virginia University, a group of emissions researchers who mainly dealt with heavy trucks noticed an unusual posting by the transportation council, which was looking for a partner to test diesel-powered cars. > > … > > It did not take long for suspicions to set in. The West Virginia researchers were well-versed in diesel performance on real roads, and had certain expectations for how the test cars should ebb and flow in their emissions. But the two Volkswagens behaved strangely. ---
**Author:** ![Diceman](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Diceman](https://boards.straightdope.com/u/Diceman)\ **Post date:** [September 23, 2015, 4:29pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/5 "2015-09-23T16:29:19Z")
My state doesn’t require emissions tests, so can someone please explain to me how the cars know when an emissions test is being administered? All I can imagine is that maybe the measuring probe creates enough backpressure that the emissions system notices something is different. Or is there normally something hooked up to the car’s electronics during the test (which would make it trivially easy to know when a test is going on)? ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [September 23, 2015, 4:39pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/6 "2015-09-23T16:39:44Z")
> [@Diceman](#): > > My state doesn’t require emissions tests, so can someone please explain to me how the cars know when an emissions test is being administered? All I can imagine is that maybe the measuring probe creates enough backpressure that the emissions system notices something is different. Or is there normally something hooked up to the car’s electronics during the test (which would make it trivially easy to know when a test is going on)? for the ten billionth time, the EPA emissions _certification_ test is what we’re talking about here. This is the test each model of car has to pass before the manufacturer is allowed to put it on the market. It is a laboratory test with precisely-controlled parameters, among which are ambient temperature, engine warm-up time, a strictly controlled drive cycle, and so on. it’d be trivial for the PCM to notice that the ambient temp is exactly 25°C, the front wheels are spinning but the rear wheels are not, etc. and these lab tests do not use a probe stuck in the tailpipe, they actually clamp around a specially shaped exhaust outlet and collect the exhaust gases for analysis. it has nothing to do with state-level inspection tests (if the state does that.) ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [September 23, 2015, 5:15pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/7 "2015-09-23T17:15:17Z")
The car’s onboard computer monitors steering wheel motion. In normal driving there is always some degree of adjusting the wheel even going straight ahead. In emission testing, the car is on a dynamometer with the steering wheel held still. If the computer didn’t sense any movement of the wheel, it kicked into clean-emission mode. ---
**Author:** ![Dallas\_Jones](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dallas_jones/32/3277_2.png) [@Dallas\_Jones](https://boards.straightdope.com/u/Dallas_Jones)\ **Post date:** [September 23, 2015, 5:32pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/8 "2015-09-23T17:32:41Z")
> [@Gary\_T](#): > > The car’s onboard computer monitors steering wheel motion. In normal driving there is always some degree of adjusting the wheel even going straight ahead. In emission testing, the car is on a dynamometer with the steering wheel held still. If the computer didn’t sense any movement of the wheel, it kicked into clean-emission mode. Gary T is right. The computer can tell when it is actually being driven by the steering wheel action, among a few other parameters. > [@](#): > > These systems included an algorithm that used the position of the steering wheel, vehicle speed, the duration of the engine’s operation and barometric pressure to determine when the vehicle was being tested and then dial back emissions to meet EPA standards. From this Scientific American article: [What's Behind VW's Downfall and Secretive Emissions Deals | Scientific American](http://www.scientificamerican.com/article/what-s-behind-vw-s-downfall-and-secretive-emissions-deals/) The people who discovered the scam borrowed a portable tester that fit in the trunk and monitored the actual exhaust out put while driving. I will see if I can find the other article I was just reading. ---
**Author:** ![Just\_Asking\_Questions](https://avatars.discourse-cdn.com/v4/letter/j/ba9def/32.png) [@Just\_Asking\_Questions](https://boards.straightdope.com/u/Just_Asking_Questions)\ **Post date:** [September 23, 2015, 5:37pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/9 "2015-09-23T17:37:39Z")
> [@jz78817](#): > > for the ten billionth time, the EPA emissions _certification_ test is what we’re talking about here. Why you being a jerk about this? Two times in one thread that’s not even at 10 posts yet is not “ten billion”. I didn’t know the answer, either. I guess we’re all not as smart as you, or something. ---
**Author:** ![Dallas\_Jones](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dallas_jones/32/3277_2.png) [@Dallas\_Jones](https://boards.straightdope.com/u/Dallas_Jones)\ **Post date:** [September 23, 2015, 5:46pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/10 "2015-09-23T17:46:26Z")
Silly me! It is the link in **Colibri** s post #4.:smack: ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [September 23, 2015, 5:49pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/11 "2015-09-23T17:49:58Z")
> [@jz78817](#): > > for the ten billionth time, the EPA emissions _certification_ test is what we’re talking about here. **Moderator Note** I’m not sure what prompted this, but it’s absurdly hyperbolic. If you’re going to respond to the question, just answer it without the snark. > [@Just\_Asking\_Questions](#): > > Why you being a jerk about this? Two times in one thread that’s not even at 10 posts yet is not “ten billion”. > > I didn’t know the answer, either. I guess we’re all not as smart as you, or something. **Moderator Note** While **jz78817’s** post was out of line, that doesn’t entitle you to engage in insults and junior moderating. If you have a problem with a post, report it. No warning issued, but don’t do this again. Colibri General Questions Moderator ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [September 23, 2015, 6:03pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/12 "2015-09-23T18:03:14Z")
it came up a few times in the MPSIMS thread about this, and in an attempt to be humorous I increase it by an order of magnitude every time I respond. guess it fell flat. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [September 23, 2015, 6:17pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/13 "2015-09-23T18:17:52Z")
> [@jz78817](#): > > it came up a few times in the MPSIMS thread about this, and in an attempt to be humorous I increase it by an order of magnitude every time I respond. guess it fell flat. You can’t assume that everyone has read the same threads that you have. In isolation it just looked ridiculous. ---
**Author:** ![Just\_Asking\_Questions](https://avatars.discourse-cdn.com/v4/letter/j/ba9def/32.png) [@Just\_Asking\_Questions](https://boards.straightdope.com/u/Just_Asking_Questions)\ **Post date:** [September 23, 2015, 6:25pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/14 "2015-09-23T18:25:40Z")
> [@Colibri](#): > > **Moderator Note** > > I’m not sure what prompted this, but it’s absurdly hyperbolic. If you’re going to respond to the question, just answer it without the snark. > > **Moderator Note** > > While **jz78817’s** post was out of line, that doesn’t entitle you to engage in insults and junior moderating. If you have a problem with a post, report it. No warning issued, but don’t do this again. > > Colibri > General Questions Moderator Will comply. I thought I was in the Pit. Sorry! ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [September 23, 2015, 6:28pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/15 "2015-09-23T18:28:45Z")
> [@Colibri](#): > > You can’t assume that everyone has read the same threads that you have. In isolation it just looked ridiculous. yes it does. ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [September 23, 2015, 6:35pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/16 "2015-09-23T18:35:47Z")
> [@Gary\_T](#): > > In normal driving there is always some degree of adjusting the wheel even going straight ahead. In emission testing, the car is on a dynamometer with the steering wheel held still. If the computer didn’t sense any movement of the wheel, it kicked into clean-emission mode. So Kansas VW owners polluted less but got crappier gas mileage. ---
**Author:** ![ElvisL1ves](https://avatars.discourse-cdn.com/v4/letter/e/5daacb/32.png) [@ElvisL1ves](https://boards.straightdope.com/u/ElvisL1ves)\ **Post date:** [September 23, 2015, 7:16pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/17 "2015-09-23T19:16:02Z")
> [@Colibri](#): > > Here’s a good article from the NY Times on it: > > [It Took E.P.A. Pressure to Get VW to Admit Fault](http://www.nytimes.com/2015/09/22/business/it-took-epa-pressure-to-get-vw-to-admit-fault.html) > [@](#): > > Even with the looming punishment, the company almost got away with it. In fact, it most likely would have if not for a strange twist of fate and the curiosity of several auto researchers. A rare real-world case of “If it hadn’t been for those meddling kids!” ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [September 23, 2015, 7:41pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/18 "2015-09-23T19:41:39Z")
> [@ElvisL1ves](#): > > A rare real-world case of “If it hadn’t been for those meddling kids!” This is just a cover story – actually, the EPA offers rewards to auto company informants who inform them about such cheating. Then they create a cover story like this one, to keep their whistle-blowers anonymous. I have no idea if that is true or not. But the EPA should start this rumor going around. It might scare the auto makers into not trying such cheats quite as often. And it might encourage some auto company workers on the inside to blow the whistle on other such as-yet-undiscovered cheating. ---
**Author:** ![harmonicamoon](https://avatars.discourse-cdn.com/v4/letter/h/65b543/32.png) [@harmonicamoon](https://boards.straightdope.com/u/harmonicamoon)\ **Post date:** [September 23, 2015, 10:35pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/19 "2015-09-23T22:35:48Z")
I can’t help thinking that maybe VW was doing what was already an accepted practice of auto manufacturers. They just got caught. ---
**Author:** ![campp](https://avatars.discourse-cdn.com/v4/letter/c/c5a1d2/32.png) [@campp](https://boards.straightdope.com/u/campp)\ **Post date:** [September 23, 2015, 10:45pm UTC](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304/20 "2015-09-23T22:45:44Z")
> [@harmonicamoon](#): > > I can’t help thinking that maybe VW was doing what was already an accepted practice of auto manufacturers. They just got caught. So then it should be easier to catch any other cheating manufacturers, now that we know how to test it. [Next page](https://boards.straightdope.com/t/just-how-did-vw-the-cheat-come-to-light/732304.md?page=2)