Hyundai and Kia have unveiled their ‘Active Air Skirt’ (AAS) technology, which minimises the aerodynamic resistance generated during high-speed driving, which in turn help improve the range and stability of electric vehicles (EVs). AAS controls the flow of air entering through the lower part of the bumper and controls the turbulence generated around the vehicle's wheels at speed.

How AAS helps reduce drag coefficient

AAS is installed between the front bumper and the front wheels of the vehicle and is hidden during normal operation; it operates at speeds of over 80kph when the aerodynamic resistance is greater than rolling resistance. Aerodynamics not only impacts performance but also driving stability and wind noise. AAS can also operate at speeds of over 200kph as its made of rubber, which reduces the risk of external objects splashing and damaging the vehicle while driving at high speeds.

The reason why AAS only covers the front part of the tyres without completely covering the front is due to the characteristics of Hyundai's E-GMP platform, which is flat at the bottom. This also enhances the downforce of the vehicle, thereby improving traction and stability.

Hyundai and Kia announced that they have tested and reduced the drag coefficient (Cd) by 0.008 by installing AAS in the Genesis GV60. Both manufacturers have also applied for patents in South Korea and the United States, and plan to consider mass production after durability and performance tests.

“This technology is expected to have a greater effect on SUVs where it is difficult to improve aerodynamic performance,” said Sun Hyung Cho, vice president and head of Mobility Body Development Group at Hyundai. “We will continue to strive to improve the driving performance and stability of EVs through improvements in aerodynamics.”

Meanwhile, Hyundai and Kia are applying various technologies such as rear spoilers, active air flaps, wheel air curtains, wheel gap reducers and separation traps to secure competitive drag coefficients. Hyundai Ioniq 6, which incorporates these technologies, has achieved a Cd of 0.21.