VW cheat emissions test with "defeat device"

[DaveW]

Here is an interesting document, well worth a read. Hopefully, it heralds the start of a rational approach to the issues. I have found no reference to "defeat", or "cheat" in the document.

[Tommy Cookers]

..... without benefit of the link posted by DW (my steam age computer won't pick it up)

since an engine when lean NOx trapping is clean and economical
and the same engine a few minutes later will be eliminating trapped NOx and thus temporily uneconomical and high in CO2 emission
a manufacturer might reasonably and naturally cause the software to recognise test mode and force normal NOx trapping settings
especially as the mandated European NEDC test uses a cold start, and so tends to lower NOx generation (and favour diesels)

btw
is lean NOx trapping available in SI engined cars ?

and these, maybe we have seen some of them already ?
http://www.theicct.org/real-world-exhau ... iesel-cars
http://www.theicct.org/blogs/staff/labo ... issions-eu - revealing the pro-diesel bias ?
http://www.theicct.org/nox-control-tech ... enger-cars - the NEDCycle favours NOx by using cold start ?
http://www.theicct.org/comparing-real-w ... vi-mar2015 - this last (HDVs not cars) conveniently finds no problem ?

and iirc there's some tradeoff between NOx and particulates - but particulates are much the larger health issue

conveniently in these climate-conscious days my annual mileage is tiny, so I escape any worries over not driving diesel

[turbof1]

There are reports that the Renault Espace Diesel also too high emissions:

http://www.reuters.com/article/2015/11/ ... OJpGut0.97

Looks like Volkswagen really opened a can of worms. Every car from every brand will now be under scrutiny. It'll be interesting to see how many of these reports we are going to get in the future.

[Phil]

I'm a little skeptical with the independent tests. Different testing circumstances will lead to different results. Maybe that Espace is producing 25 higher NOx under circumstances not tested? I think the key point in all of this is, is a defeat device being used? - which is what makes this this whole thing a huge big scandal.

It's a little like 0-60mph times. Manufacturers will often claim numbers that are rarely achieved in the real world. Well, some manufacturers perhaps give out more realistic numbers than others. I.e.; Lotus seems to test their cars in a vacuum or in a giant tunnel with a giant propeller generating god knows how much tail wind and perhaps a sling shot system used on aircraft carriers to give jets a shorter take-off range to achieve their acceleration figures. Test it in the real world on aggressive tarmac and summery temperatures and you're hard put to get close to them. How different can it be with these emission tests that test a very predictable, repeatable circumstance?

[turbof1]

I'm a little skeptical with the independent tests. Different testing circumstances will lead to different results. Maybe that Espace is producing 25 higher NOx under circumstances not tested? I think the key point in all of this is, is a defeat device being used? - which is what makes this this whole thing a huge big scandal.

It's a little like 0-60mph times. Manufacturers will often claim numbers that are rarely achieved in the real world. Well, some manufacturers perhaps give out more realistic numbers than others. I.e.; Lotus seems to test their cars in a vacuum or in a giant tunnel with a giant propeller generating god knows how much tail wind and perhaps a sling shot system used on aircraft carriers to give jets a shorter take-off range to achieve their acceleration figures. Test it in the real world on aggressive tarmac and summery temperatures and you're hard put to get close to them. How different can it be with these emission tests that test a very predictable, repeatable circumstance?

Something has gone wrong somewhere anyhow. 25 times the CO2 (CO2, not NOx) emission limit is too high and needs to be investigated further. It could be a measurement error at DUH, on purpose or not, but it needs to be investigated by the official organs.

[Shooty81]

There is more Information:

http://www.spiegel.de/auto/aktuell/rena ... 64285.html
Renault Espace: Certain conditioning of the car the day prior the test led to good emission tests. If the procedure is not 100% followed, the emissions rise significant.


http://www.spiegel.de/auto/aktuell/opel ... 59319.html

Basically the Opel Zafira showed good results when only the frontwheels were on the testrig, as soon as the rear wheels were rolling on a 4 wheel rig, the emissions increase drastically.


Clear evidence of defeat devices.

[TzeiTzei]

Something has gone wrong somewhere anyhow. 25 times the CO2 (CO2, not NOx) emission limit is too high and needs to be investigated further. It could be a measurement error at DUH, on purpose or not, but it needs to be investigated by the official organs.

Wouldnt that mean 25 times bigger fuel consumption?

[turbof1]

Very inprobable. The cars run a catalytic converter to reduce the amount of CO2. It simply means that the amount of CO2 exiting the exhaust pipe comes closer to the amount of CO2 produced by combustion.

[SiLo]

The list is slowly building up then. I'm currently working for a large car manufacturer and have had people that work in engine development tell me that we don't do anything like this. I don't believe them and am waiting for most car companies to get caught with their pants around their ankles.

The irony that there is a big climate push going on at the moment regarding CO2 emissions as well...

[TzeiTzei]

Very inprobable. The cars run a catalytic converter to reduce the amount of CO2. It simply means that the amount of CO2 exiting the exhaust pipe comes closer to the amount of CO2 produced by combustion.

I didnt know that a catalytic cnverter reduces co2 emissions.

[turbof1]

I was assuming it did this. Looking at information I could be very wrong about it .

[TzeiTzei]

I was assuming it did this. Looking at information I could be very wrong about it .

No worries . I'm no expert. I think co2 is directly related to fuel consumption and nox has something to do with temperature.

[Brian Coat]

Actually CO2 increases very slightly across the cat.

CO + O2 > CO2
NOx > O2 + N2
uHC + O2 > CO2 + H2O

[Shooty81]

I was assuming it did this. Looking at information I could be very wrong about it .

No worries . I'm no expert. I think co2 is directly related to fuel consumption and nox has something to do with temperature.

25 times NOx, not CO2!

[Shooty81]

The list is slowly building up then. I'm currently working for Ford and have had people that work in engine development tell me that we don't do anything like this. I don't believe them and am waiting for most car companies to get caught with their pants around their ankles.

The irony that there is a big climate push going on at the moment regarding CO2 emissions as well...

3 companies doing that doesn't mean all companies!