Diesel cars fitted with modern particle filters and catalysts emit fewer carbon emissions than their petrol counterparts, new research suggests.
Particle emissions from cars are huge contributors to smog and air quality, and while diesel engines produce less carbon dioxide, they do produce more nitrogen oxides and particulate matter because of the way the fuel combusts.
But with new filters? Diesel is kicking petrol’s butt.
The tests put diesel ahead of petrol for reducing emissions, with petrol cars producing 10 times more particulate matter on average when cars are running at 22ºC, and 62 times more at -7ºC.
Now, it’s worth noting the same size for these tests were relatively small – only six diesel vehicles and 11 petrol vehicles were used in the lab tests. We’d want to see a wider range of vehicles in real-world testing in order to draw a more solid conclusion from the study.
The researchers do point out in the study that emissions from vehicles are sensitive to the location, age and ambient temperature of the cars tested, and admit further studies to work out an average are needed.
Carbonaceous particulate matter is a toxic part of vehicle exhausts made up of black carbon, primary organic aerosols (including solid particles from combustion) and secondary organic aerosols (produced though the atmospheric ageing of organic compounds released during combustion).