Ioniq 6 Achieves Hyundai's Lowest Ever Drag Coefficient of 0.21

CD 0.21 is Top-Tier Among Electric Vehicles
Streamlined Curves, a Decisive Factor

[Asia Economy Reporter Kiho Sung] Hyundai Motor Company announced on the 6th that the ‘Ioniq 6’ has achieved a drag coefficient (CD) of 0.21, the lowest among all Hyundai models released to date.

The aerodynamic performance of a vehicle significantly affects various aspects of vehicle performance, including ▲power performance ▲fuel (electric energy) consumption efficiency ▲driving stability ▲driving noise (wind noise), making it one of the key indicators for evaluating product competitiveness. Especially with the transition to the electric vehicle era, competition to secure better driving range on a single charge has intensified, making the relationship between the car and aerodynamics increasingly important. The drag coefficient of 0.21 achieved by the Ioniq 6 ranks among the top levels of existing electric vehicles and has greatly contributed to increasing driving range.

Hyundai Motor Company, centered around the Hyundai Design Center and Vehicle Performance Development Center, combined the strengths of various departments within the research institute to pursue ‘achieving the best aerodynamic performance’ from the early stages of Ioniq 6 development through design and engineering. As a result, the efforts of the research team to improve aerodynamic performance can be seen throughout the design of the Ioniq 6.

The exterior design of the Ioniq 6 features a streamlined silhouette completed with clean and sophisticated curves, which facilitates smooth airflow around the vehicle. Various aerodynamic technologies have been extensively applied, including ▲rear spoiler ▲external active air flap ▲wheel air curtain ▲wheel gap reducer ▲separation trap ▲wheel deflector and under cover shape optimization.

The rear spoiler is the component that contributes most significantly to improving the aerodynamic performance of the Ioniq 6, serving to reduce both drag, which refers to air resistance, and lift, the force that causes the vehicle to lift upward.

The Ioniq 6 itself has a streamlined shape similar to an airplane wing, which generates lift due to the pressure difference between the upper and lower parts of the vehicle when driving at high speeds. At this time, the downforce generated by the rear spoiler stabilizes the rear of the vehicle, reducing lift and ensuring driving stability even at high speeds.

Hyundai Motor Company devoted great effort to the development of the rear spoiler to achieve optimal aerodynamic performance for the Ioniq 6. Using morphing technology, a shape deformation technique, and computational fluid dynamics analysis, they derived the optimal result from about 70 different spoiler shapes. They repeatedly conducted full-scale prototype production and wind tunnel testing to finalize the ideal position and shape.

The active air flap (AAF) applied to the front bumper effectively reduces cooling drag, which accounts for more than 20% of the total vehicle air resistance. The flap opens when cooling is needed and closes to block airflow into the vehicle interior during normal conditions, thereby reducing air resistance.

In line with the characteristic of electric vehicles having a closed grille, the Ioniq 6 places the air flap at the very front to maximize the effect of reducing air resistance. The integrated flap, which connects two flaps into one, also serves as a guide for airflow when open, enhancing cooling efficiency.

Although the Ioniq 6 has a longer wheelbase to secure interior space, resulting in a relatively short front overhang that is somewhat disadvantageous aerodynamically, Hyundai implemented a wheel gap reducer that effectively extends the left and right ends of the front bumper in front of the front wheel arch. As a result, the space between the wheel arch and the wheel is effectively reduced, guiding the airflow from the front to avoid separation at the wheel, thereby maximizing the aerodynamic performance of the aero wheels.

Additionally, Hyundai applied a separation trap to the rear combination lamp and lower bumper of the Ioniq 6, putting the finishing touch on its aerodynamic performance.

The separation trap is applied along a line that coincides with the end of the rear spoiler and extends laterally, designed to detach the airflow moving along the side of the vehicle at a consistent position, allowing the air to flow out more smoothly. This works together with the disturbed air at the end of the rear spoiler to help reduce drag on the Ioniq 6.

A Hyundai Motor Company official said, “The Ioniq 6 was developed with a focus on functional design that combines the streamlined aesthetic design with the creative ideas of aerodynamic researchers, resulting in the lowest drag coefficient among all Hyundai models. Numerous researchers devoted themselves to developing it with the goal of realizing functional beauty that enables longer driving distances.”

Meanwhile, Hyundai plans to reveal detailed product features along with the digital world premiere of the Ioniq 6 on July 14 and showcase the actual vehicle for the first time to domestic customers visiting the '2022 Busan Motor Show.'

This content was produced with the assistance of AI translation services.