VW cheat emissions test with "defeat device"

[Tommy Cookers]

today's figure from the BBC TV for UK annual 'NOx death' is 23500 (and a seperate 29000 for 'particulate death')
and they report that emission test levels will be tightened

since the BBC acts as a self-appointed, unelected, Government which has relentlessly campaigned pro-diesel for 30 years
creating and manipulating public opinion and unfairly influencing the elected Governments ......
I assume that hundreds of BBC and Government members and staff will now be resigning in recognition of their dereliction ....

[DaveW]

today's figure from the BBC TV for UK annual 'NOx death' is 23500 (and a seperate 29000 for 'particulate death')

For those interested, the BBC's report can be found here.

Background documents can be found here.

[ChrisM40]

If the 'update' resulted in less power and economy them surely the owners have a case for compensation. The car is no longer as described.

What about second hand values? A usual VW strong point. If my car was suddenly worth thousands less id be very upset..

Second hand values that's the point the would have me pissed off if I owned a VW diesel,
The value of your investment has dropped far beyond what normal usage of the vehicle would do.

A normal car is a money sink not an investment. If you buy a car from new, what grounds do you have to be annoyed that the value of your car has dropped as a result of this? At the time you buy it, you cannot be sure of it's value when you decide to sell it.

Not entirely true and no one said they were an investment. The second hand values of brands and models and well known, some like VW and Toyota are good and some like large french cars are bad. Its something like 40-50% after 3 years v. 20% after 3 years. Some are even better, ive seen 70%+ for the super eco city cars like the Toyota aygo.

VWs sell on their residual value because while expensive new, they lose less value over time and are therefore better 'value' over their lifetime. This is going to hurt that residual value.

[R_GoWin]

@WilliamsF1: I'm by no means an expert, but I believe the NOx is a byproduct simply by burning diesel, like CO2 is a byproduct when burning gasoline. Lean burn will probably cause more NOx emissions, but note that that same lean burn has a higher efficiency and allows for more horsepower. Having a less le burn will drop both fuel economy and power.

NOX is not a product of ‘lean burn’. In fact the exact opposite - rich burn and lean burn are NOx mitigating strategies. If you are to draw a graph with NOx on Y axis and Equivalence ratio on X axis – you will end up with a bell shaped normal distribution curve – with peak production occurring at Eq. ratio = 1 and NOx drastically falling away on either sides (lean and rich).

The concept of ‘lean burn’ does not hold good for diesel combustion anyway – because what lengthscale will you consider to base this on? If you take the combustion chamber as a whole – its always lean as you are smoke limited in Diesels and the AFRs are high. Its your local Eq ratio in the vicinity of the spray that matters in diesel combustion regimes. And over here the fuel is highly stratified. You do not have one flame front like that of PFI or during the homogenous mode of a GDI – instead multiple local ones hanging around individual droplets, and combustion occurring everywhere you have the atomised fuel.

NOx is a product of lean burn or is it?

So in all probability the top end would not change.

Unless Nitrogen is present the fuel – such as coal, wood etc which would give rise to additional sources of NOx - almost all of the NOx for automobiles is thermal NOx. The atmosphere contains ~78% nitrogen. So anything that burns in air will produce NOx as long as the adiabatic flame temperature is higher than 1700-1800K range – from a cigarette lighter to jet engines.

The components of Nox are the active NO species and passive NO2. 60-90% of NOx is NO. (depending on speed-load conditions). While temperature is the driving factor for this 'zeldovich mechanism' - NO formation is a 2 way reaction - there is production and decomposition. And this balance between NO production and decomposition is a factor of species concentrations on the flame surface, local pressure, temp, local eq ratio etc. During the expansion stroke - as the piston moves past 50-60 deg CA ATDC - the gasses cool down <1700K and the zeldovich mechanism is kinetically limited - you have what is called as NOx freeze and it just hangs in there until exhaust valve opens. So all the NOx is formed from the point of injection till about 60deg CA.

[djos]

Here in Aus there's some talk of full vehicle replacements by Volkswagen and Audi.

[R_GoWin]

&Tommy: I was being told they were less strict. It could be wrong however. I was under the impression EU was more stringent on CO2 emissions but less on NOx, with US vice versa. But again, it might be incorrect.

No, you're right. IIRC, the NOx limit is something like 4-5 times higher in the EU compared to USA. That's for euro 4 and euro 5 ratings.

Its quite hard to look at the absolute values of NOx or Soot and say EPA is lower than Euro etc - because the test cycles are different. The test cycles are meant to mimic local driving habits and a typical European urban and extra urban driving cycle different to US - length, speed limits etc. For all you know the Euro could have had a few harsher transients - and this could have been reflected in a more generous allowance for NOx in terms of legislation to account for this. So in theory both could have been equally hard.

Generally the EPA and Euro are very close to each other.

[langwadt]

@WilliamsF1: I'm by no means an expert, but I believe the NOx is a byproduct simply by burning diesel, like CO2 is a byproduct when burning gasoline. Lean burn will probably cause more NOx emissions, but note that that same lean burn has a higher efficiency and allows for more horsepower. Having a less le burn will drop both fuel economy and power.

NOX is not a product of ‘lean burn’. In fact the exact opposite - rich burn and lean burn are NOx mitigating strategies. If you are to draw a graph with NOx on Y axis and Equivalence ratio on X axis – you will end up with a bell shaped normal distribution curve – with peak production occurring at Eq. ratio = 1 and NOx drastically falling away on either sides (lean and rich).

snip

but lean burn means you cannot easily run a three-way catalytic converter to reduce the NOx

[R_GoWin]

Personally I cringe when I hear expensive Merc's and BMW's clatter by me and wonder why someone would waste their money on a luxury vehicle only to power it with a glorified tractor motor!

I was at the WEC event at Silverstone this year and for me personally - I will take the sound of the Audi diesel anyday! It wins hands down.

[djos]

Personally I cringe when I hear expensive Merc's and BMW's clatter by me and wonder why someone would waste their money on a luxury vehicle only to power it with a glorified tractor motor!

I was at the WEC event at Silverstone this year and for me personally - I will take the sound of the Audi diesel anyday! It wins hands down.

Meh, it's got nothing on the classic R8. I saw them at the petit lemans in Adelaide in 2000, now those sounded fantastic!

The only cars that sounded better were the judd 3.5ltr v10's which sounded like the F1 engines I think they were based on, in a word... Incredible!

[autogyro]

The more noisy it is the less efficient it is.
The future is electric.
Shhhhhhhhhhhh

[djos]

The future is electric.
Shhhhhhhhhhhh

On this we agree, I can't wait till full Battery Electric Vehicles are affordable to buy!

[cma]

The future is electric.
Shhhhhhhhhhhh

And how much better for the environment are all those batteries? All those heavy metals, acid, etc...All the output from burning more fossil fuels or nuclear fuels will generate a heck of a lot more emissions than they currently do now. Plus there isn't enough generating capacity to charge all these electric vehicles so a load more concrete, steel and construction is needed to build more power stations to cover this shortfall.

Yep, very green and efficient. Just moves the concentration of pollutants from city centres to the countryside. But as long as its away from the politicians they don't mind.

[Tommy Cookers]

The more noisy it is the less efficient it is.
The future is electric.
Shhhhhhhhhhhh

not really - until there's a fiftyfold expansion of renewables that are actually renewable ie low carbon

a road EV is typically 35% efficient (and 45% at best) from prime mover input to vehicle output - a race diesel is typically 45%

from power station output to EM output the road EV typically has 15-20% losses


10 million EVs in London all making beeping noises to warn pedestrians !! (this billionaire Zac Goldsmith has promised, if elected)
subsidised by robbing the ICE car owners of $1000 - $2000 a year ??
or further extending our national debt beyond its current $3000000000 route
let them use their lavish public transport that the rest of us subsidise from afar !

APOLOGIES TO ALL for my habit of posting then redraughting/redrafting
it's because my computor setup is archaic and I can't draft in the proper place

[R_GoWin]

The future is electric.
Shhhhhhhhhhhh

On this we agree, I can't wait till full Battery Electric Vehicles are affordable to buy!

but Zac Goldsmith wants to be London Mayor, so says London should go EV (subsidised no doubt) 'to save thousands'

Not to mention that batteries have the energy density of less than a choco chip cookie! I dont have a problem with actors in showbiz collecting awards in their environmental vehicles or Tesla wooing the outliers - but you've got to be a science freak to suggest you would legislate to make a whole city run on EVs. The technology is not ready for upscaling and mass consumption in a way that wouldnt shift the problem to another industsry or leave a trail of destruction in its wake (let alone making financial sense).

Even despite all the greenwashing - and the mythical 8% improvement year on year in energy density of storage devices or whatever - you are still clutching at straws.

I definitely see an increasing level of electrification of the powertrain - but ICE is not going to get pushed out in a hurry.

[MadMatt]

The future is electric.
Shhhhhhhhhhhh

On this we agree, I can't wait till full Battery Electric Vehicles are affordable to buy!

They are affordable and numerous, just check around you. Issue of course is range, but that goes with technology so progress has to be made to make these cars great to have. If you have a bit more money than average, Tesla has interesting products!