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Nearly All New Diesel Cars Exceed Official Pollution Limits (theguardian.com)
An anonymous reader writes: The Guardian, citing a comprehensive set of data, reports that 97% of all modern diesel cars emit more toxic nitrogen oxide (NOx) pollution on the road than the official limit. A quarter of this voluminous number emits at least six times more than the limit. From the report, "Surprisingly, the tiny number of models that did not exceed the standard were mostly Volkswagens, the carmaker whose cheating of diesel emissions tests emerged last year sparked the scandal. Experts said the new results show that clean diesel cars can be made but that virtually all manufacturers have failed to do so. The new data, from testing industry leader Emissions Analytics (EA), follows the publication this week by the Department for Transport of emissions results for 37 vehicles, all of which emitted more NOx on the road than the official limit. But the new data covers more than 250 vehicles in more stringently standardised road conditions. EA found that just one of 201 Euro 5 diesels, the EU standard from 2009, did not exceed the limit, while only seven of 62 Euro 6 diesels, the stricter standard since 2014, did so. Diesel cars must meet an official EU limit for NOx but are only tested in a laboratory under fixed conditions. All vehicles sold pass this regulation but, when taken out on to real roads, almost all emit far more pollution. There is no suggestion that any of the cars tested broke the law on emissions limits or used any cheat devices. Mayoral candidates in London, the city with the worst air quality in Britain, have seized on the DfT data to call for tighter controls on polluting traffic -- including a ban on diesel cars."Caroline Pidgeon, the Lib Dem mayoral candidate, said: "The figures are exactly the reason why we need to speed up the introduction of the ultra-low emission zone so that it starts in 2018. Ultimately we will need to ban diesel vehicles from much of London and we need a mayor prepared to take these tough decisions and work with people to make these changes happen."
Limits must be defined in terms of the condition of the test. If testing is done outside those defined conditions, the limits are hard to apply and enforce. Seems like the regulators need to re-define the limits and testing method.
I am shocked, SHOCKED, that clean diesel is just another totally meaningless advertising slogan!
Also note that the lab test limits were set at a lower level knowing that real world conditions would be worse. So exceeding limits in the real world was actually expected, the question is how much worse is expected.
What it actually means is slightly less dirty diesel.
Even if new diesel cars did pass this test they'd still start blowing black soot and other crap after a number of years have passed and the car has reached owner number 3 who isn't bothering to do anything other than basic maintainance to keep it on the road until it falls apart.
1. What formally defines "Clean Diesel". "Euro 6" is spectacularly uninformative.
2. How badly the standard was blown: a few percentage point, or orders of magnitude ?
3. Some historical data. For instance, what did emissions look like before ANY emission controls were put in place.
Furthermore, the Guardian article offers zero actual numbers. As an engineer, I'm always skeptical of any claim when no specific numbers are mentioned. Gee, real-world conditions aren't well-replicated in testing environments ? I'm shocked, shocked, I tell you, to hear it. But I suspect a real-world testing regime for all vehicles would be both costly and cumbersome, and probably non even cost-effective. . ..
The way things are going, electric cars will get huge boost and eventual dominance when cities will start banning all non-zero emission vehicles from driving within city limits.
And all the emissions will be shifted to countryside where power plants can pollute to their heart desire because population density (and associated health problems) over there are close to nil.
The NOX issue (the one in the article) has nothing to do with the fuel and everything to do with the temperature of combustion. Diesel engines are efficient because of the combustion temperature and that causes NOx to form. If Gasoline engines were raised to similar efficiencies they would start to develop similar NOx issues.
Diesel engines aren't more complex than petrol engines (especially with the advent of modern common rail injector systems). They don't have a throttle or ignition system of any sort. They have to be built heavier because of higher compression ratios.
Diesel is used in tractors and big rigs because of efficiency. The gallons per mile per ton are lower with diesel.
Where in the world are you getting that diesel engines are more complex? All you need for the ignition cycle is fuel and compressed air. Bam that is it. A turbo in a diesel engine Diesel engines only became complicated because of BS emissions requirements levied by do nothing eurocrats.
Diesel cars/trucks are light years better than gasoline on the sheer basis the engines last longer. NOx means nothing when you're gas car dies at 125k and you need to buy a new one. The level of emissions that go into making a car outweigh the small amount of NOx outputted anyday.
Save the environment and drive your car longer!
My reaction to this though is "so what?"
The meaningful questions are does improvement on the lap test predict improvement under real word conditions?
It does not have to mirror real work conditions to be useful.
If the answer to the first question is yes does meeting the lab test standards mean a vehicle will have a meaningfully improved pollution profile as compared to if we did not bother setting standards and testing?
Again the point here is to reduce the output of harmful airborne pollutants. Are we doing that or not, is really all the matters. If the real world effect is .01% than we are wasting effort and resources if its %10 percent in the lab but %7 on the road its still probably a win. Again we need to compare with equipment in common use before standards were enacted.
Is there a more predictive test design that could be implemented?
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Unfortunately, yes. And that is what eventually kills a society: Too many self-centered fucks that do not care about anything except themselves.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
The meaningful questions are does improvement on the lap test predict improvement under real word conditions?
It does not have to mirror real work conditions to be useful.
/quote> I'm not sure why that is meaningful. A test method and limit should be set with knowledge of the relationship to real world conditions, and reasonable certainty you are keeping actual emissions levels within an expected range.
Correct. TFA is making the assumption that the test limits are never supposed to be exceeded, which is a questionable assumption. The EU test is radically unlike typical driving, which unless the EU states otherwise suggests the correct interpretation is that normal operating emissions are supposed to be x times more than test emissions. TFA presents nothing new. It's been widely known within the industry for years that EU testing conditions generated less emissions than normal operation.
This ambiguity was also present in the U.S. tests. After the truck diesel scandal around 1998-2000, the EPA firmly established that the test limits are not supposed to be exceeded during normal operation, and the test was merely sampling certain operating conditions to make sure the vehicles were in compliance. The EPA test however is more representative of typical driving.
If we avoid lab conditions, you bring in random factors. So some heavy polluting car could just get lucky and have no sharp stops and quick speed ups, which is where it happens to heavily pollute, so it passes.
We need lab conditions to ensure a fair comparison between different cars.
It is assumed that all cars vary from real life to lab conditions in roughly the same manner. That is, that a car that does best in the lab conditions will also do best in real world conditions, even if the real use pollutes far more heavily.
In addition, we assume that the lab is similar enough to real world so that we know how much we are polluting.
If either of those assumptions are false, it indicates a bad lab condition set up which needs to be fixed. But that is not the fault of the car companies, but instead the fault of the politicians and scientists that designed the lab. (Yes, it is often designed by politics, not scientists.)
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It also has the benefit of exposing you to an absurd amount of germs. ...thus keeping your immune system in good shape.