Tesla has released a new video to demonstrate the effectiveness of its HEPA (High Efficiency Particulate Air) filtration system and Bioweapon Defense Mode that come standard on every new Model Y, Model S, and Model X electric vehicle.

Offered on the Model X and Model S since 2016, the HEPA filter and Bioweapon Defense Mode were introduced on the Model Y last year. When these two combine, they keep nearly all traces of pollution and particulate matter out of the vehicle cabin. Tesla claims the filtration system removes 99.97% of airborne particulates, protecting occupants from polluted air.

For this experiment, Tesla used a giant bubble, parked a Tesla Model Y and a BMW X3 inside it, and then fired up some smoke bombs in the bubble. Obviously, the HEPA filter-equipped Tesla had Bioweapon Defense Mode activated, while the BMW only had its standard filtration system and no Bioweapon Defense Mode (the German automaker does not offer such a feature).

To show that it stands by its product, Tesla had one employee sit in the driver’s seat of the Model Y during the experiment, while the X3’s cabin remained empty.

The video shows how the cabin of the EV remained free from red smoke as the interior of the BMW got invaded by it. After the experiment, a Tesla thermal systems engineer removed the Model Y’s massive activated carbon filters and the HEPA filters underneath them, revealing that they had captured a lot of red dust.

The HEPA filter used in Teslas is inspired by air filtration systems used in hospitals, clean rooms and the aerospace industry, and is said to remove 99.97% of airborne particulates, such as smoke, bacteria and pollen. 

The filtration system is active whenever climate control is pulling in outside air. In extreme conditions, users can activate Bioweapon Defense Mode, which positively pressurises the vehicle’s cabin, preventing pollutants from leaking in. In this mode, all air is filtered through the HEPA and gas media filters.