The purification equipment that is a must in a passenger car can be legally removed if the vehicle is rebuilt into an A-tractor. However, how much it affects emissions is unclear.
In 2022, there were over 50,000 registered A-tractors in Sweden, which was double the number compared to 2019.
There is very little knowledge about this because hardly any measurements have been made. Since A-tractors are becoming more common, it's also extra interesting, says Nina Svensson, who is leading the study.
An earlier, incomplete study found that particle emissions can be a thousand times higher, and gas emissions such as nitrogen oxide can be five to ten times higher.
Although A-tractors probably do not constitute a national environmental problem due to the number of vehicles, they can have a local impact, according to Nina Svensson.
If there are many A-tractors in the same place and the surrounding conditions are poor, it can lead to poor air quality. But how great the impact is, we'll see.
The study will last for two years and is a collaboration between the Swedish National Road and Transport Research Institute VTI and the IVL Swedish Environmental Research Institute. The Swedish Transport Administration is financing the project.