Vehicle emissions standards are very strict. They’re only going to get stricter as the world gears up to fight climate change whilst maintaining our standards of living. But as we all know, some car manufacturers have been trying to get around these standards by fitting emissions cheat devices to their vehicles. Volkswagen was the first to be caught out, and other European manufacturers have been suspected of doing the same thing. It seems there’s mounting evidence that Mercedes Benz is the next to get in trouble.
So you might ask; what’s the big deal? Why can’t car companies just design and build cars in accordance with the rules? The problem is diesel. It’s a very useful fuel, in that it generates a lot of torque and is generally more fuel efficient than petrol engines. However, due to its chemical composition, it’s pretty nasty stuff. Like cancer causing nasty.
Europe has some of the strictest emissions standards in the world. A lot of that has to do with the amount of carbon dioxide generated. But there are also standards for the carcinogenic particulate matter generated when burning diesel. These are hard to control and neutralise (read, very expensive). However, in order to test for compliance, governments only test vehicles in a lab and not in the real world. Most car owners know that the rated fuel economy of their cars is only an indication, and the real fuel economy varies depends on many factors.
Given tests are in a lab, Volkswagen engineers decided they would just design emissions cheat devices to detect when it was being tested and behave within the rules. Any other time, the engines would be very naughty and generate a whole lot more pollution than allowed. It seems Mercedes has now been caught with similar devices in its Vito vans. The German government has ordered a recall of the Vito, accusing them of cheating on emissions tests.
Mercedes denies all of this. But the German website Bild reports that Mercedes C-class cars are also suspected of housing emissions cheat devices. Given diesel passenger vehicle sales are dropping – particularly as petrol engines catch up – this might not be such a big problem in the future. But eventually, petrol engines will also hit a ceiling of efficiency and driveability. Will more and more car manufacturers rely on cheating to get through emissions testing?