Which car is the cleanest for the environment?
The differences are small and diesel is certainly not the worst.
Suppose you want to buy a new car and you want to take clean air into account as much as possible. Which car do you choose? We sorted out an electric, a hydrogen-powered car, a diesel, a gasoline, and a natural gas (CNG) car. The results are amazing.
First we make clear what an environmentally friendly car is. The environment, that is air pollution: fine dust and nitrogen oxides, for example, that come out of the exhaust, among other things. Nitrogen dioxide is especially harmful to the respiratory tract, and fine dust can cause cancer. Environment is therefore different from the climate. Climate has to do with greenhouse gases, such as CO2. The more CO2 in the air, the stronger the warming. CO2 is directly related to the use of fossil fuels. The more you consume, the more CO2 goes into the air. But we'll talk about in a separate article. In this aritcle we limit ourselves to particulate matter and nitrogen oxides.
We did an extensive literature study, read several test reports from inspection bodies and consulted three universities and did a practical test ourselves, with equipment from Testo, a German company that specializes in gas measuring equipment.
Cars with combustion engines spew out quite a few unhealthy things into the air, including fine dust. The diesels in particular have a bad reputation. But according to several studies, modern diesels would do a lot better, and would definitely not deserve that bad reputation.
We put it to the test and tested the fine dust in the exhaust of both a diesel, a gasoline and a car on CNG. And the results were surprising: the diesel was the best of the three. It emitted 1,500 particles per cm³.
The CNG car turned out to be surprisingly emitting slightly more particles than the diesel: 5,000 per cm³. And with gasoline, the difference was even bigger: it produced no fewer than 15,000 particles per cm³. The test illustrated what we had previously heared from various car technicians and inspection authorities: that they were surprised at how little some diesels did emit. Even fewer than natural gas or CNG cars, which are generally considered to be very clean.
Modern diesels also do surprisingly well for the other hazardous substance, the nitrogen oxides. This is because new diesel engines have AdBlue and they actually completely eliminate the nitrogen oxides. AdBlue is the brand name of a chemical that you have to refuel separately and that is injected automatically when your engine is running.
Gasoline engines have a catalyst and gas engines also have that. So nitrogen oxides are not immediately a problem over there either. Combustion engines today have so much technology on board that the exhaust isn't the problem anymore. A natural gas car no longer has any advantages over a diesel and gasoline engine. Not because they have deteriorated , but because diesel and gasoline engines have become much cleaner than before.
So the gains made by diesels, gasoline and gas cars for the emission of harmful substances are spectacular. The worst values for the particulate matter during our test were gasoline cars with around 15,000 particles per cm³. But 10-year-old diesels spewed out above a million particles on this test, almost 70 times more!
What about electric and hydrogen cars
A great deal of progress has therefore been made to control harmful emissions, but a small amount of particulate matter and nitrogen oxides is still released. Because it is inherent of burning by burning fossil fuels.
A problem that does not exist with other car technologies. With electric cars and hydrogen cars, there is no combustion whatsoever while driving. An electric car has no exhaust pipe from which nitrogen oxides, particulate matter and other harmful substances are blown into the air. And only water comes out of the hydrogen car's outlet. Hydrogen cars make electricity by connecting hydrogen to the air, a clean chemical process with pure water as the "waste product".
Another story for fine dust. These particles are not only released during incineration, but also due to tire wear during driving. And the heavier the car, the greater the wear. Electric cars and cars powered by hydrogen are generally heavier than similar diesel, gasoline or natural gas cars, mainly due to the weight of the batteries. They easily weigh 2 tons.
Critics point out that the fine dust emissions caused by tire wear and, to a lesser extent, braking, is even greater than what is currently coming from the exhaust pipe of modern diesels. Others emphasize that these particles are much less harmful to health then combustion related particles.
And there are other uncertainties: for example, what is the environmental impact of a battery? Or when the electricity from your electric car comes from a coal-fired power station, how do you settle the particulate emissions from that power plant in the life cycle of an electric car?
Clearly, electric cars running on batteries or on hydrogen, diesels, gasolines and natural gas cars are becoming cleaner every day. Their negative impact on air pollution and the environment has become increasingly smaller. The real fight is about the car that is the least harmful to global warming. He also wins the prize for the best car for the planet, but that's for our next article.