The active aero of Hyundai's upcoming EV is the sort of thing that would have been reserved for supercars a decade ago.
The Hyundai Ioniq 6 is almost the world's most aerodynamic production car, and the Korean automaker has now shown how it has achieved a drag coefficient of just 0.21, matching the Lucid Air. Lightyear claimed the title of the most aerodynamic production car in history earlier this year, with a figure of 0.175, but we are yet to see one on the road. A more accurate benchmark, therefore, is the Mercedes EQS, which has a drag coefficient of 0.20.
It's very impressive that Hyundai has come so close to the Lightyear and the Mercedes claim, especially when you consider that both of those EVs are priced in the six-figure range, while the Ioniq 6 is estimated to start in the low $40,000 range. Just like a Porsche 911 GT3 RS, the Ioniq 6 boasts clever active aero solutions that look very simple but took an age to perfect.
Hyundai notes that aerodynamics are essential for all cars but are particularly critical for electric vehicles. Aerodynamic efficiency not only affects the car's range but also significantly affects performance, stability, and noise. Without an engine to mask the sound of the wind and tires, a smooth body contributes to a calm and quiet driving experience.
Hyundai's styling boss Simon Loasby says that 'Streamliner' cars, including the 1947 Stout Scarab, Phantom Corsair, and Saab Ursaab, influenced the Ioniq 6's design.
"Ioniq 6 started with a single curve that defines its profile and architecture - the ultimate streamlined form - and 'Electrified Streamliner' became the pet name for the car," recalls Loasby. "The true beginning of aerodynamic design and engineering started in the 1930s and we felt that taking inspiration from that era - and indeed from nature - was the perfect way to create uniqueness and sustainable performance in the EV segment."
The Supermarine Spitfire British fighter plane from World War II, also influenced the car's design, with a Spitfire-inspired winglet added to the side of the Ioniq 6's rear spoiler "to absorb the airflow from the roof and reduce drag by minimizing vortices at the spoiler's lip."
The body's overall shape is also similar to that of the wing of an airplane, with lift generated aerodynamically by the pressure differences between the top and bottom of the car and the downforce created by the rear spoiler, ensuring high-speed stability.
Jinhyuck Chang, Hyundai Motor Company's head of aerodynamic development, adds that the design team also took notes from nature, "especially the shape that a peregrine falcon takes when it dives after prey at 390 kph [242 mph]."
When the initial work on the exterior was complete, wind tunnel testing began "to chase another 10% of efficiency." This took an immense amount of work, including using what is known as the "morphing technique," a shape transformation technology, and computational fluid dynamics (CFD) analysis.
This was especially beneficial in perfecting the shape of the spoiler, allowing the designers to choose from roughly 70 different options. This technology also led to an active air flap in the front bumper, wheel air curtains, wheel gap reducers, separation traps, and wheel deflectors.
Let's take a quick look at how these elements contributed to the Ioniq 6's claimed 382-mile range (FWD with long-range battery) according to the Worldwide Harmonized Light Vehicle Test Procedure (WLTP) standard.
The active air flap in the front bumper reduces cooling resistance, which Hyundai says accounts for more than 20% of total air resistance. This flap opens when needed and closed when it's not, and since this is an EV, its cooling demands are far lower than those of a combustion-powered car. When open, it directs air to the radiator, and when closed, its valley-like shape guides air to the tilted air intake and works with the wheel air curtain and wheel gap reducer.
The wheel air curtain features a vented hole in the side of the bumper rather than the front, helping to send air around the outside of the tire to prevent air separation over the wheel, reducing turbulence. Because of a relatively short overhang, a passive solution in the form of a wheel gap reducer was added to the front of each front wheel arch, effectively extending the front bumper.
At the rear of the car, a separation trap was added between the combination rear lamps and the lower section of the rear bumper. This is designed to guide airflow more smoothly "by applying a line that coincides laterally with the tip of the rear spoiler to drop the flow of air to the side of the vehicle." Along with the diffused air at the tip of the rear spoiler, drag is further reduced.
Even under the car, Hyundai has worked for greater efficiency, incorporating an undercover and a diffuser under the rear bumper. An optimized front wheel deflector and a minimized wheel guard gap further enhance aerodynamic performance.
"In the EV era, air resistance is more important than any other performance," says Executive VP and Director of Vehicle Performance Development Min Byung-hoon. "Through their collective efforts, Hyundai's aerodynamic engineers and designers have achieved with Ioniq 6 a new benchmark for Hyundai and the Ioniq dedicated EV lineup brand."