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Behind the Cummins/FCA suit

by David Zatz on

Yesterday, we posted an article on a lawsuit brought by four owners of Ram (or Dodge Ram) pickups with Cummins diesel engines. Their basic claim is that the pickups produce so much in the way of nitrides of oxygen (NOx, where the “x” means “one or more oxygen atoms”) that they both pollute at more than the legal limit, and wear out their catalytic converters too quickly.

Cummins diesel engine

The second claim is rather interesting, as it shows some ignorance as to how catalyst works. The catalyst is not used up. Catalysts work by making some chemical reactions happen at a much lower temperature than normal (by giving their own electrons and getting back new ones). Catalyst does not, in itself, “go bad,” though it may need cleaning, and the structure holding it can break. Stationary industrial catalysts are used for years, periodically washed with strong acids to uncover the surface.

The first claim is hard to judge from the evidence provided. Cummins has been a leader in emissions reduction, untouched by scandal or incompetence so far. Their diesels for Dodge pickups met emissions standards years before they needed to. We have already seen that standard emissions testing is generally “looser” than real world usage, and we don’t have the details about the trucks at the heart of the lawsuit.

Differences in emissions results can come about from different instruments and processes as much as anything else; just like tow ratings, horsepower, and even cargo capacity vary depending on how you measure them. Regulators may likely set a tighter limit than the real target, knowing that real world emissions will be higher than those in the lab.

cummins diesel engine

Even with all this, we have no way of knowing how these four trucks were maintained, and the quality of fuel that went into them. Cummins and Ram test using fuel that meets Federal standards; but there have been many reports of substandard fuel over the years. In addition, if the owners were running biodiesel, they would naturally have higher NOx levels. Likewise, since more is emitted at high temperature, testing on hot days would bring higher emissions.

As for the point behind it all: why we even bother restricting NOx emissions (as we have done for over four decades). There are several basic reasons, but first, we have to point out that even now, cars, trucks, buses, and trains, account for over half of all human-caused NOx.

First, NOx (along with volatile organic compounds, or VOCs, such as fuel vapors) causes smog, which older readers may remember as having been a real problem in cities such as Los Angeles and New York. It also reacts to form ozone, which at ground level can damage the lungs, particularly of children and the elderly. Around half of Americans live in places with too much ground-level ozone.

When the ozone contacts salt mist from the ocean, it forms nitryl chloride, which is fair toxic. Some reactions of NOx with VOCs bring the creation of various toxins that cause mutations in children. It is also a substantial contributor to acid rain, which has caused a great deal of damage to cars, crops, buildings, and bridges, among other things (the United States started to address acid rain under President Reagan).

That said, only time will tell as to whether the lawsuit is, as Cummins insists, an offensive attack on a blameless company, or, to use FCA’s tone, “meritorious.”

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