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Diesel Dupe
Diesel’s Dirty Secret

Diesel was, for a time, considered by some to be a greener alternative to unleaded gasoline. Those days seem numbered, as the environmental case against the fuel is starting to look stronger. As the AP reports, new research suggests that diesel’s pollution is being grossly underestimated all over the world:

The work published Monday in the journal Nature was a follow-up to the testing that uncovered the Volkswagen diesel emissions cheating scandal. Researchers compared the amount of key pollutants coming out of diesel tailpipes on the road in 10 countries and the European Union to the results of government lab tests for nitrogen oxides.

They calculated that 5 million more tons (4.6 metric tons) was being spewed than the lab-based 9. 4 million tons (8.5 million metric tons). Governments routinely test new vehicles to make sure they meet pollution limits.

Experts and the researchers don’t accuse car and truck makers of cheating, but say testing is not simulating real-world conditions.

Europe has a long history of gaming its car emissions tests, and it’s a history we’ve been following for some time. Testers get creative to juice extra mileage out of vehicles, employing such novel techniques as removing side-view mirrors to reduce drag, taping up doors, and removing “extras” like stereos to make vehicles lighter.

This lax testing has made diesel to seem more environmentally friendly than it actually is. Diesel’s green case was dubious to begin with, though: the fuel emits more local air pollutants than gasoline, and has been blamed for the recent rise in toxic smog in many of Europe’s biggest cities. Europe saw this as an acceptable trade-off, however, because diesel is capable of getting higher mileage.

But it seems as if those local pollutants being spewed out of the tailpipes of diesel-powered cars and trucks are a bigger problem than previously believed. So much for Europe’s “green” credibility.

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  • Blackbeard

    Well, President Obama said, in Paris at the occasion of his signing the climate treaty that is, of course, not a treaty, that the Earth would soon become uninhabitable if we didn’t dramatically reduce CO2 emissions. Consider that for a moment: At the very least “uninhabitable” means the extinction of human life although it may very well mean the extinction of all life on Earth. And President Obama would never exaggerate, would he?

    So let’s put this in perspective: Yes, VW cheated on their emission tests and in doing so betrayed their customers, their workers and their shareholders, as well as breaking the law. No excuse for that is possible and indeed some executives are already in jail and no doubt others will soon be too. And this fiasco has already cost them many billions with, no doubt, more to come. All perfectly justified.

    But now the developed world is moving towards banning diesel altogether. Remember the diesel engines of today emit a tiny fraction of the pollutants emitted by the old, uncontrolled diesels of 20 years ago. And remember too that diesels get dramatically better gas mileage than conventional gasoline powered vehicles and hence emit dramatically lower amounts of CO2. And remember what Obama said about CO2 soon making the world uninhabitable.

    Are we all sure we’re making the right decision to slightly reduce NOx and particulate emissions in return for an increased possibility of wiping out all life on Earth?

    • Josephbleau

      As well, reduction in coal fired power production is reducing the supply of pozzolanic fly ash which is a 1:1 replacement for Portland cement. This is increasing production of clinker which emits 45 pct of it’s weight in deadly co2. The humanity.

  • Andrew Allison

    Diesels became popular for reasons of fuel economy, not the environment. Until about ten years ago, diesel EPA fuel efficiency was 30-35% higher than for gas and the fuel cost less. This, and the high cost of fuel, is the reason why fully half of all passenger cars registered in Europe in 2016 were diesel powered. In France, 80% of the overall French passenger fleet is diesel.

  • Fat_Man

    TAI’s post focuses on European diesel car testing, but the article is about: “Pollution from diesel trucks, buses and cars
    globally”. I don’t know if there are any testing or pollution controls imposed on commercial and municipal vehicles in either Europe or Asia. Diesel passenger vehicles are only a tiny portion of the global fleet of diesels. Even in the US pollution controls on commercial diesels lag behind those on consumer vehicles.

  • Angel Martin

    Diesel’s dirty secret is that it is that diesel engines are inappropriate for passenger vehicles – except is a world of outlandish taxes and regulations.

    Noisy, smelly and low on power, diesel is appropriate for constant load engines running at a constant speed = long haul trucks.

    And applications where high peak torque and low horsepower are appropriate – like commercial vehicles and mining and agriculture equipment.

    • Josephbleau

      So true, great for charging submarine batterys. The best of all is electric motors moving under a D.C. Wire, powered by a coal power plant.

    • Andrew Allison

      Well yes, but Europe does, in fact, have outlandish taxes on fuel. This made (things have changed) the fuel efficiency of diesel engines extremely attractive, and resulted in them dominating the European passenger car fleet. Incidentally diesels are not only not noisy, smelly and low on power, but they consume far less fuel than gas engines when idling (a common condition in cities). And, by the way, just as today’s gas engins are more efficient, diesel emissions have been reduced dramatically. The problem, and the cause of the pollution problems, is the existing fleets.

  • For the record, regarding the Nature study, as a portion of global NOx emissions, on-road diesel cars and heavy duty trucks contribute only 20%- i.e 80% of the NOx comes from other sources. As for the testing itself, the testing protocols are established by the government. As acknowledged here, the lab tests are imperfect and everyone knows that, and there are efforts to develop more representative kinds of tests. Emissions inventories are themselves estimates, and subject to wide ranges of uncertainty of the fleet composition and operating characteristics.

    The contribution of NOx emissions to ozone formation itself is influenced by constantly changing meteorological conditions and other factors. The accuracy to which one can project benefits or impacts foreword two decades or more based on many assumptions and models, each with its own uncertainty, seems questionable.

    Today’s generation of new diesel technology is lower in emissions and more efficient than one built 10 or even five years ago. Older technology engines met the standards in place at the time, and as this study points out, standards have become progressively more stringent.

    In the U.S., new technology diesel trucks and buses have reduced NOx emissions by more than 95 percent compared to older models. Today, it would take 60 new diesel trucks to equal the same emissions from one pre-1988 truck. NOx emissions are just one of several contributors to air pollution, including ground level ozone. There are many sources of NOx emissions, including power plants, industrial activity and mobile sources like cars, trucks and off-road equipment. According to U.S. EPA, emissions of oxides of nitrogen have fallen by 61 percent since 1980. Heavy duty highway truck NOx emissions dropped by 69% from 1980-2014 . In 2016 U.S. EPA reviewed the current NO2 national ambient air quality standards and in its policy assessment, recommended that no changes to the health-protective standard are needed as existing control measures continue to contribute to declining NO2 emissions,

    • FriendlyGoat

      Thanks for a detailed description of progress and how it has been obtained.

    • Andrew Allison

      I agree that the jury is not out on diesel overall, but because passenger car traffic is so concentrated in large cities, the negative impact is focused there.

  • Pete

    Love it. The all-knowing Euro-trash are caught with their pants down again.

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