One of the biggest news stories this last fortnight has been the Volkswagen emissions cheating scandal. In a “wildly illegal” strategy spanning many years, Volkswagen deliberately ‘cheated’ on emissions tests of its diesel vehicles, with software which could identify when the car was undergoing a test, and activate emissions controls only during those times. 11 million vehicles were affected, across a number of brands (including Audi and Skoda). The fallout has included the CEO resigning, a 30% drop in share price, and huge cost to the company (they’ve set aside €6.5 billion for starters).
The “emissions” at issue were nitrogen oxides, which are local air pollutants, contributing to smog and respiratory diseases. I don’t think they’re considered greenhouse gas emissions (correct me if I’m wrong) – nitrous oxide certainly is, but it’s not emitted by diesels.
Diesel cars have been popular in Europe (more than 50% of the car fleet in some countries) because they create less greenhouse gas emissions than petrol cars. They use 30% less fuel, but diesel has about 10% more energy, so on the whole they’re 20% more efficient. The downside is that they tend to produce more pollution – nitrous oxides, microscopic solid particles and the like. “Clean diesel” cars supposedly have plenty of hardware and software in place to help reduce their polluting.
These pollutants are supposed to be tightly regulated, since they can have such a big impact on air quality in cities. But that’s not much help if manufacturers figure out ways to beat the system.
And whether or not it’s being done deliberately, many cars from other manufacturers don’t meet the standards when they hit the roads either:
Road tests of more than a dozen popular models from several manufacturers showed that the raw nitrogen oxide emissions from the cars were on average seven times European standards, according to a little-noticed October report from the same outfit that flagged the VW problems.
Indeed, experts said it could very well be that the high levels of real-world emissions reflected in the ICCT report show not that firms are cheating, but only that it’s all too easy to design a car that passes governmental lab tests for emissions. Once outside the lab, those cars fail in real-world conditions.
Nick Molden, chief executive of Emissions Analytics, a British firm, said that in recent years, Europe had put in place two new standards for tailpipe emissions, each one stricter than before.
“But there was no improvement in air quality,” Molden said. “That was the alarm bell. These results suddenly explained why every major European city has an air quality problem.”
The problem, he said, is that the governmental certification test in Europe “is so gentle. It’s 20 minutes in a lab.”
It’s hard to replicate real-world conditions in a lab, and it’s no surprise that when manufacturers know how they’re going to be tested, they design cars that are designed with those tests in mind – with less consideration to what happens on the road.
Plus, the gap between theoretical performance and on-road performance is an issue for greenhouse gases as well. I wrote a post last year based on a Ministry of Transport presentation:
“Essentially, vehicles have always tended to use more fuel on the road than they do when they’re being tested. But the performance gap has gotten larger [for Japan and a number of European countries]. Car manufacturers are becoming very adept at designing cars to do well in the tests, but not on the road”.
As an aside, NZ has a much higher proportion of diesels in the fleet than the US, but we’re much lower than Europe. 8.3% of our ‘light passenger vehicles’ (i.e. cars) and 68.4% of ‘light commercial vehicles’ (i.e. goods vans and small trucks) are diesels. Looking at the number of diesel vehicles which have entered our fleet in the last few years, I would have guessed that there are probably thousands of VW-made vehicles in New Zealand which are affected, but the head of Volkswagen New Zealand has said ‘hundreds’ and plans to give more info this week, so he will probably provide a more precise figure.
Update 6/11/2015: There were apparently 5,548 diesel cars in New Zealand fitted with the software, and “other imports of around 150”, whatever that means. Carbon dioxide issues are also being reported on “at least 800,000” cars worldwide, with some of those petrol. It is not yet clear how many New Zealand cars are affected by this.