Hyundai Nexo has a built in air purification system that it says will clean the air as it drives. But this feature has divided car enthusiasts and environmentalists. It's a groundbreaking technology that will help clean the air in cities, say some, while others think it's just a marketing ploy with minimal real world impact. The principle behind the system is that it filters the air which goes into the fuel cell to remove fine dust and other pollutants. According to Hyundai, a single hour of driving will purify as much as 26.9 kg of air. But there are still questions about the effectiveness of this system over the long term, how it might affect the car’s performance, and whether it’s really making a difference in air quality. Discussions are also had regarding the environmental tradeoffs of the production and disposal of the filters used for this system.