VW cheat emissions test with "defeat device"

[lio007]

if anybody is interested how the "defeat device" works, here's a nice video:

http://www.thetruthaboutcars.com/2015/1 ... ode-video/

[djones]

So I understand most of the video above (51 min onward).

They are only using adblue when the car detects its in a test cycle.

Ok....

But why not just use the 'map' that activates it all the time?

What advantage is there in NOT using it?

[turbof1]

So I understand most of the video above (51 min onward).

They are only using adblue when the car detects its in a test cycle.

Ok....

But why not just use the 'map' that activates it all the time?

What advantage is there in NOT using it?

The video did explain that. Using too much adblue will create a toxic byproduct (was it ammonia?). Furthermore, VW would need to use that excessive amounts of adblue to keep within the limits that they can't stretch until the car has to take a service. They would need to refill it after perhaps as soon as 5000-8000km after the last service.

[djones]

He explained one tricky part of the system is if you use too much.

But that's too much.

They are using none at all, unless its in a test mode.

He also says the expected fill for AB is 1,000km, so it will always be outside of service schedule.

That aside, is that the only reason then.... so the customer is not always filling up the AB?

[turbof1]

I think 1,000km is a bit exagerated, but indeed you will definitely be well outside your service schedule.

Adblue is I think a relative costly substance. Imagine how well it goes down with customers when they have to pay quite a bit for each top up, not to mention the annoyance of having to bring the car in just to top up your adblue.

Although reading further you can apperently do it yourself at some oil stations. Still, it'd be an extra cost and extra effort that will scare potentional customers away.

[djones]

I think that is a factor then - not annoying customers.

I have also just read when not using AB you get better economy.

So I guess the official emissions test is a different routine to the economy test, or they would shoot themselves in the foot for that.

[FW17]

I dont see why price is a concern

It uses 1.5 liters every 1000 km and costs $2 a liter (or $3 every 1000 km)

[djones]

The main factor then has to be the economy.

When its in reduced emissions mode the economy is not as good.

[FW17]

What would be reduced milage?

VW claims 44 mpg you get 50 mpg now? So reduced milage would mean less than 44 or 50?

[bill shoe]

Well, crap. I had been assuming (hoping?) the emissions scandal was limited to isolated but far-reaching bad decisions at VW. Not.

Except that Daimler doesn’t call it a defeat device. In tests by Netherland’s official automobile inspector TNO on behalf on the Dutch Minister of the Environment, a C-Class Mercedes C220 TDi BlueTec was found emitting more than 40 times the amount of cancer-causing NOx than in the lab. After Dutch TV picked up the tough to ignore scent, the Stuttgart automaker complained that the tests were done at temperatures below 10 degree centigrade (50 F).

http://www.forbes.com/sites/bertelschmi ... 913ffc1891

“There is, says Mercedes, a shut-off device in the engine management of its C-Class diesel cars that stops the NOx cleaning under these and other circumstances. This is for the protection of the engine, and permissible, says the Stuttgart automaker.“

http://www.spiegel.de/auto/aktuell/merc ... 75185.html

I've previously written things to the effect that there is a difference between violating the letter vs the spirit of the regulations, implying that violating the spirit but meeting the letter was OK overall, or at least less bad. Hard to put it into words, but I have much less confidence in that position now. This scandal feels bad and getting worse.

Mercedes-Benz, inventor of the car and a company carried for 130 years by genuine Engineering Excellence, is reduced to obviously silly arguments to explain their cheating emissions.

[djos]

Just more evidence showing that Diesel engines are completely unsuited to wide spread use in regular passenger vehicles!

[Tommy Cookers]

I rather agree with the last 2 posts

the emissions regs have always legitimised and even compelled a misrepresentation of the real-world emissions
eg for 30+ years the US tests allowed the car pre-soaked to 28 deg C so the catalyst action was artificially quick
and for years the European test was much fairer

historically real emissions (control) fell short, being typically twice the level nominated in the regulations (and still so in SI cars)
now regulated emission level is so much tighter but the mandated tests procedures are still slack so real emissions shortfall is bigger
though in other situations people are happy with govt-mandated fraud, eg accounting of lightbulb efficiency and EV and Plugin Hybrid efficiency

test compliant real emissions shortfall is not cheating, because the law has been complied with
it's only regulator incompetence or regulator corruption and collusion
any regulator or government surprised (by test-compliant shortfall) should resign

the Euro 6 and US and other equivalents - are they not in effect European protectionism that has been exposed by the EPA 'attack' ?
the EU motorcycle helmet standard was held by experts elsewhere to be bogus (providing no real benefits) and unfairly protectionist
but it was never officially opposed

[Edis]

Just more evidence showing that Diesel engines are completely unsuited to wide spread use in regular passenger vehicles!

Read the study instead of the article, the article gets most of it wrong anyway.

The test results of the sixteen tested vehicles show good CO, THC and PM10 real-world emissions because the applied technologies for controlling these emissions are intricately robust. In almost all conditions the emissions are low. However the real-world NOx emission of all vehicles varies from 0 to 2000 mg/km. Although the type approval emissions of all vehicles are below 80 mg/km, the average real-world NOx emission of all tested Euro 6 vehicles varies between 150 and 650 mg/km.

In other words, these diesel engines have low emissions, except for NOx. As we can see, all cars are above the 80 mg/km limit in practice but we can also see that the worst car has more than four times the average NOx emissions than the best car.

Some current Euro 6 vehicles have been equipped with DPF, EGR and SCR technologies and they have the potential to yield low real world emissions but the EGR and SCR technologies are only partly activated.

So, the NOx emissions are high because the emission reduction technologies aren't used to their full potential. Now, no one have been accused of cheating like VW did, rather this is the result of poor legislation which allow the manufacturers to optimize their cars for low emissions in the test and once outside the test cycle they can optimize their cars for other things like "engine protection" and low Ad-blue consumption.

As we can see from the quote below it's mostly high pre-cat emissions that are to blame for the high NOx emissions in real world driving conditions. The main difference between cars with low and high real world NOx emissions can also be found in the pre-cat values, where the low emitters have low pre-cat values. This tells us that some manufacturers chose to do things like reduce the EGR rate and advance injection timing once outside the test cycle, which increase pre-cat NOx emissions above what the selective catalytic reduction can handle.

However, in the on-road tests the pre-SCR NOx emissions are 2 to 5 times higher than in chassis dynamometer tests. This elevated NOx emissions before the SCR-catalysts is the main cause for the high vehicle emissions...

The study also points out that since a real-world emission test was introduced for heavy vehicle type approval the NOx emissions have rapidly declined. As other studies have found, a heavy truck can today actually have a lower real-world NOx emissions than a small diesel passenger car. This shows that legislation can have a large impact on real-world NOx emissions.

Oh, and NOx is in itself not "cancer causing" like claimed in the article. Infact, in concentrations typically found in the air it's not directly toxic for humans. The problem is instead that NOx is very reactive and can react with other pollutants in the air and create new toxic compounds. Still, the health effects of NOx are low compared to that of particulate matter, which is the main air quality problem today. While more than half of the NOx emissions are caused by exhaust emissions of road traffic, exhaust emissions from road traffic is responsible for a much smaller share of the total emissions of particulate matter.

[Tommy Cookers]

PM2.5 is the big thing, because there are additional physiological effects at this particle size, eg penetration of arterial and brain tissue
medical science imo has the impression that vehicles are the major source

this week the UK had another heavyweight report claiming 44000 (early) deaths annually plus iirc 11000 from indoor air pollution
99000 annually in the EU from indoor pollution alone
indoor pollution from eg gas-cooker NOx, air fresheners and cleaning products, wood stoves etc
another scientist disagreed, saying only smoking and Radon produce indoor pollution deaths

but city air pollution is lower than it has been for 1000 years
what would NOx phobes make of 1960s chemistry classes, we 13 year olds pouring concentrated 'red fuming' Nitric acid in the open ?

[strad]

As I recall the first pollution devices like the EGR etc. cleaned up 90% of the pollutants. Since then we've worked at cleaning up that last 10%. Of course I don't see how you're ever going to get down to zero as long as you use internal combustion engines of any kind.