Clean air project

Working with supplier MANN+HUMMEL, Audi has developed a filter for use on its ever-expanding range of fully-electric models, that is designed to continuously filter harmful particulates from the air while the vehicle is driving around and while stationary for charging.

It works much like stationary filtration systems that are already in use in some cities, but this mobile version ensures that not only are the car’s own particulate emissions absorbed, but also those of other vehicles as well – literally as the vehicle is driven around the city.

The filter is integrated into the vehicle’s existing airflow in front of the radiator so that only a few modifications to the car are necessary. The filter element is controlled via the switchable cooling air inlet and its mechanical function is similar to that of a vacuum cleaner. By a similar principle, the fine dust particles remain stuck in the filter and the air can still flow through it.

The pilot project was launched in 2020 and will run for four years, with initial tests used to determine not only how efficient the system would be but also to ensure that it wouldn’t adversely effect the vehicle’s performance.

After over 50,000 kilometres of endurance tests on the Audi e-tron, the filters have been proven to have no negative effect on the operation of the electric vehicle, including on hot summer days or during fast charging.

“This particulate filter is an example of our pursuit of innovation for everyone’s benefit and a successful collaboration with specialised suppliers. We are already doing a lot today on our own initiative. We anticipate it will also become a legal requirement in the future,” says 

Fabian Groh, Project Manager in Attachment System Development at AUDI AG.

The system is so effective that, depending on the usage scenario, the Audi e-tron particles are completely filtered out in a highly polluted city such as Stuttgart.

To make the system even more efficient, Audi is working with MANN+HUMMEL to connect with existing sensors such as weather stations, plus they plan to develop a display logic in the vehicle, allowing passengers to determine when the system is active and how much has already been filtered.

All testing to date points to a great success with no discernible drawbacks. The filter is easy to maintain and needs only be replaced when the regular service interval has been reached. A lifecycle analysis of the entire filter system has shown that it will account for 14.9 kilograms of CO2 equivalents. In addition, the filter itself consists of 15 percent recycled material and the entire system is 60 percent recycled.