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Nearly all new diesel cars exceed official pollution limits

theguardian.com

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Re: Nearly all new diesel cars exceed official pollution limits

#11

Post by jacquesm »

Someone wrote: post #7
f_allwein wrote: post #2

> There is no suggestion that any of the cars tested broke the law on emissions limits or used any cheat devices. Since all these cars passed the laboratory test, that means there must be something very wrong with the test and the way the standards are enforced. Or all car makers do cheat.

A bit/lot of it may be "optimize for the test", not cheat. They know at what temperature the test is done, so they optimize the chemistry for that case. They know it will be done with new cars, so they do not optimize "emission over the car's lifetime". They also have drivers who are above average. That will help with manually shifted cars. And of course, they pick the best car they can produce, and prepare it optima…

"Dynamometer testing is already supplemented by on-road testing using portable emissions equipment, lab testing of cars borrowed from consumers, audits of other industry emissions labs and examination of vehicles chosen randomly from assembly lines, said Valentine, the EPA spokeswoman."

from: http://www.autonews.com/article/20150929/OEM11/150929807/epa...

So the manufacturer apparently does not get to chose the vehicle, which is one reason why the cheating code was present in all VWs with that engine model rather than just in the vehicles used for the testing.

Re: Nearly all new diesel cars exceed official pollution limits

#12

Post by Spare_account »

f_allwein wrote: post #6
stinos wrote: post #3

Earlier quoted context omitted.

I thought it was common knowledge the lab tests are a joke? Has been posted on HN as well IIRC.

I thought it was more a case of "some car manufacturers cheated" and not "almost all diesel cars emit several times more than they should". How is this possible?

The test is accurate and measures emissions very well. The cars emit NOX at levels lower than the legal limits during the test. There is no mistake during the test and no cheating (apart from VW).

However, when the cars are used by normal drivers, the usage patterns are so significantly different than the test sequences that the emissions profile changes. In the majority of cases the NOX emissions from cars used by normal people exceed the EU limits.

This does not, as I understand it, mean that the cars are illegal. The cars all passed the tests in the test environment. That is the requirement and they met the requirement.

No law is being broken but that is only because the law is not fit for purpose.

Re: Nearly all new diesel cars exceed official pollution limits

#14

Post by makomk »

f_allwein wrote: post #6
stinos wrote: post #3

Earlier quoted context omitted.

I thought it was common knowledge the lab tests are a joke? Has been posted on HN as well IIRC.

I thought it was more a case of "some car manufacturers cheated" and not "almost all diesel cars emit several times more than they should". How is this possible?

The tests simply don't match modern real-world driving patterns. For example, apparently real-world drivers tend to accelerate much more rapidly than in the test sequence. It doesn't just affect diesel cars either; they tend to over-estimate the fuel efficiency of all cars and presumably under-estimate their pollution levels too.

Re: Nearly all new diesel cars exceed official pollution limits

#15

Post by walshemj »

_yosefk wrote: post #5

"Unlike other parts of the world, European nations incentivised the use of diesel vehicles over the last 20 years because they emit less carbon dioxide per mile than petrol cars. Governments thought stricter regulation would sharply reduce NOx emissions, but carmakers found ways around the rules and governments failed to clamp down on the practices." How typical in so many ways (I particularly like the claim that gov…

I rember at the time when the push for diesel Mrs Thatcher as an ex chemist queried this - asking why not lean burn petrol engines.

This is just another example of Politicians and civil servants making poor judgement on technical matters and a lack of common sense.

The fiasco that is the eu cookie law is another example

Re: Nearly all new diesel cars exceed official pollution limits

#17

Post by verytrivial »

I'm willing to take down votes for this position, I don't understand the fuss here, nor to credulity of the actors whom should have (and probably did) know better. If the tests were meant to reflect real-world conditions, they should be be designed to do that -- they clearly weren't, and were only tiny sample of performance from which (wild?) extrapolations were drawn.

Don't have a cry about it, fix the tests. Get together some disinterested parties to design them to capture the behaviour we all apparently expected the current dud tests to measure.

This actually reminds me of how the failure of the bodies responsible for banking oversight cry WOE when the industries they were charged with overseeing did bad things. Failure of real oversight again. And it the same way, we have these same bodies (NOT end users) expecting to be paid for making these mistakes. Who benefits from the fines? Not car owners, not car makers.

Re: Nearly all new diesel cars exceed official pollution limits

#18

Post by makomk »

andy_ppp wrote: post #10

Ouch, that's gotta hurt: "Surprisingly, the tiny number of models that did not exceed the standard were mostly Volkswagens"

Not terribly surprising. Their engineers are competent, it's just that the US (where diesels are less popular) set some rather unpleasant requirements for diesel cars, in particular insisting that they couldn't require the diesel exhaust fluid tank to be topped up by the end user and setting lower NO2 limits. In order to meet these conflicting requirements, VW cheated. I think some of the VWs they tested actually have the same engine and emissions control system as some of the US models that cheated, just without the defeat device intended to reduce exhaust fluid usage.

Re: Nearly all new diesel cars exceed official pollution limits

#19

Post by awjr »

verytrivial wrote: post #17

I'm willing to take down votes for this position, I don't understand the fuss here, nor to credulity of the actors whom should have (and probably did) know better. If the tests were meant to reflect real-world conditions, they should be be designed to do that -- they clearly weren't, and were only tiny sample of performance from which (wild?) extrapolations were drawn. Don't have a cry about it, fix the tests. Get to…

There is a lot more riding on these tests than is currently being admitted. The simple fact is that based on the tests and the impact of NOx on population health, the sale of diesel cars should be stopped immediately.

Even London has doubled the congestion charge fee for diesels.

A further step would be to recognise that petrol cars also emit NOx and that the long term goal should be the removal of these from the road.

Politically this is a hard thing to do, however some countries are forcing the issue http://www.autoexpress.co.uk/car-news/consumer-news/95237/du...

This is going to hurt the car industry in ways we don't fully understand yet. In the short term I would be end-of-lining their diesel production and restructuring to electric.

Re: Nearly all new diesel cars exceed official pollution limits

#20

Post by leoc »

_yosefk wrote: post #5

"Unlike other parts of the world, European nations incentivised the use of diesel vehicles over the last 20 years because they emit less carbon dioxide per mile than petrol cars. Governments thought stricter regulation would sharply reduce NOx emissions, but carmakers found ways around the rules and governments failed to clamp down on the practices." How typical in so many ways (I particularly like the claim that gov…

What the Guardian neglects to add is that (IIRC) the German auto industry had placed a big bet on diesel engines as far back as the early '80s, and that the German government has enormous clout in the EU and seems to love German export industries with the same fervour that the US and UK governments adore their national financial sectors.
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