VW in trouble over alleged US emission test manipulations

[Alucidnation]

RobDickinson said:

Alucidnation said:

Is it me or is it just the Americans that are complaining the most?

Well given its their system they cheated, and VAG is surprisingly not an American company, its not a surprise..?

Good point.

[xjay1337]

File could not be opened.

[RobDickinson]

"The US Justice Department announced on Wednesday that Volkswagen would pay $4.3 billion in civil and criminal fines and plead guilty to three criminal charges pertaining to the automaker’s diesel emissions scandal. The DOJ also announced an indictment of six high-level VW Group executives, who are charged with lying to regulators and destroying documents."

http://arstechnica.com/cars/2017/01/vw-group-likel...

[xjay1337]

GroundEffect said:

NOx isn't produced by incomplete combustion, it's very high combustion temps/pressures that cause it. Diesel with its massive compression ratios sees very high cylinder pressures (therefore temps) therefore NOx is worse.

There's only so many ways to reduce NOx:

- Reduce fueling to reduce peak cylinder temps
- EGR
- LNT
- SCR

CO2 is basically intrinsically linked to mpg. One is fairly linear to the other.

But Vws "fix" was increased rail pressures for better atomisation?

So a more complete burn happens

I agree the co2 and mpg are linked, but this is not linked with nox output.

Edited by xjay1337 on Wednesday 11th January 23:24

[lee_erm]

xjay1337 said:

I agree the co2 and mpg are linked, but this is not linked with nox output.

Edited by xjay1337 on Wednesday 11th January 23:24

It seems completely reasonable to me that the release of all waste oxides is proportional and increasing. If a fire burns, it produces C02, NO and NO2 proportionally. Add more fuel to that fire, and it produces more of each each oxide.

Can you suggest why this isn't the case with a diesel engine?

[xjay1337]

lee_erm said:

It seems completely reasonable to me that the release of all waste oxides is proportional and increasing. If a fire burns, it produces C02, NO and NO2 proportionally. Add more fuel to that fire, and it produces more of each each oxide.


Can you suggest why this isn't the case with a diesel engine?

You can't say , well you claim it's wrong, so i'm claiming you're wrong, and asking you to tell me why!

Look at NOX output and CO2 emissions output.
They are not linked.

[Alucidnation]

Aren't you bored yet?

[George111]

xjay1337 said:

You can't say , well you claim it's wrong, so i'm claiming you're wrong, and asking you to tell me why!

Look at NOX output and CO2 emissions output.
They are not linked.

No, they are not directly linked but the way you manage one of them will affect the other. There are a lot of variables and changing some of them will change others, some of which will affect MPG.

[xjay1337]

I agree George

It is a bit tedius so that's all from me haha.

[GroundEffect]

xjay1337 said:

GroundEffect said:

NOx isn't produced by incomplete combustion, it's very high combustion temps/pressures that cause it. Diesel with its massive compression ratios sees very high cylinder pressures (therefore temps) therefore NOx is worse.

There's only so many ways to reduce NOx:

- Reduce fueling to reduce peak cylinder temps
- EGR
- LNT
- SCR

CO2 is basically intrinsically linked to mpg. One is fairly linear to the other.

But Vws "fix" was increased rail pressures for better atomisation?

So a more complete burn happens

I agree the co2 and mpg are linked, but this is not linked with nox output.

Edited by xjay1337 on Wednesday 11th January 23:24

Thermal NOx refers to NOx formed through high temperature oxidation of the diatomic nitrogen found in combustion air.[13] The formation rate is primarily a function of temperature and the residence time of nitrogen at that temperature. At high temperatures, usually above 1600 °C (2900 °F), molecular nitrogen (N2) and oxygen (O2) in the combustion air disassociate into their atomic states and participate in a series of reactions.

https://en.wikipedia.org/wiki/NOx#Fuel

You need oxygen to get NOx production. An incomplete combustion means a lack of oxygen. Your logic doesn't add up.

I think we don't know everything they changed - I highly doubt it was just rail pressure that was adjusted. What about EGR rate or SCR duty cycle?

[Fastdruid]

Seems Audi did the same in China as well
https://www.forbes.com/sites/bertelschmitt/2017/02...

[deaglecat]

delta0 said:

https://onedrive.live.com/?authkey=%21AII8a0cFXX1v...
Pretty significant loss.

Combustion temperature is a major factor in CO2 and NOx levels. Diesel and petrol engines have significantly different temperatures. Other factors like burn time, exhaust recirculation etc. also contribute.

Edited by delta0 on Wednesday 11th January 21:06

And those graphs are, in a nutshell, why folk are complaining that their cars feel neutered after the fix. Look at the torque curve between 1600 and 2400 rpm - there is substantial loss.

VW again being disingenuous, sure "max" BHP and "max" torque unaffected but the way is is delivered at the lower end of the rev scale (where lots of diesels spend their life) is worse performing. A significant dis-benefit in having the fix applied.

[Alucidnation]

Yawn.

[Oilchange]

All coming undone, lies and deception signed off at the highest levels. Executives gaoled and massive fines in the US alone. What will they do in China, put them up against the wall?
VAG will be the size of Caterham or Westfield soon, and significantly less arrogant.
I look forward to the balance of power, automotively speaking, transferring from the Germans, elsewhere.

[h0b0]

A friend of mine received a cheque for $17k for his 4 year old 120k mile golf from VW. He was very happy with the outcome.

[Fastdruid]

deaglecat said:

delta0 said:

https://onedrive.live.com/?authkey=%21AII8a0cFXX1v...
Pretty significant loss.

Combustion temperature is a major factor in CO2 and NOx levels. Diesel and petrol engines have significantly different temperatures. Other factors like burn time, exhaust recirculation etc. also contribute.

And those graphs are, in a nutshell, why folk are complaining that their cars feel neutered after the fix. Look at the torque curve between 1600 and 2400 rpm - there is substantial loss.

VW again being disingenuous, sure "max" BHP and "max" torque unaffected but the way is is delivered at the lower end of the rev scale (where lots of diesels spend their life) is worse performing. A significant dis-benefit in having the fix applied.

Wow. I missed those previously. That's a pretty shocking chasm in the torque curve. I would be pretty pissed with that.

[SevenSpeedStickShift]

R.I.P Diesel
1890- Soon
You were just getting good, but dieselgate, petrol and abnormally high NOx and pollution levels is killing you off.

Edited by SevenSpeedStickShift on Saturday 25th February 17:07

[Monkeylegend]

SevenSpeedStickShift said:

R.I.P Diesel
1890- 2015
You were just getting good, but dieselgate, petrol and abnormally high NOx and pollution levels killed you off.

Plenty of life left yet, and it is 2017 already.

[SevenSpeedStickShift]

Monkeylegend said:

SevenSpeedStickShift said:

R.I.P Diesel
1890- 2015
You were just getting good, but dieselgate, petrol and abnormally high NOx and pollution levels killed you off.

Plenty of life left yet, and it is 2017 already.

Is it? Diesel is being either banned or taxed out of countries as we speak, but it could still last a bit longer

[Plug Life]

SevenSpeedStickShift said:

R.I.P Diesel
1890- Soon
You were just getting good, but dieselgate, petrol and abnormally high NOx and pollution levels is killing you off.

Good riddance!