Revolutionary Design: Audi A6 Sportback e-tron Sets New Standards

With an exceptionally low Cd value of 0.21, the Audi A6 Sportback e-tron stands out as the most aerodynamic Audi ever and leads its segment within the entire VW Group. The A6 Avant e-tron also achieves an impressive Cd value of 0.24, placing it among the best in its body segment. Aerodynamics developers Andreas Lauterbach and Matteo Ghelfi, along with wheel designer Andreas Valencia Pollex, share insights on achieving these record-breaking values through meticulous attention to detail.

Audi's Legacy of Aerodynamic Excellence

The Audi has a long history of prioritizing aerodynamics in its vehicle designs. The NSU Ro 80, launched in 1967, featured an aerodynamic, wedge-shaped body with a Cd value of 0.35, revolutionizing automotive design. In 1983, the third-generation Audi 100 (C3) boasted a Cd value of 0.30, which was exceptional at the time. Following this, the third-generation Audi 80 (B3) continued the legacy with a drag value of 0.29. Now, the Audi A6 e-tron is set to write a new chapter, proving once again that Audi seamlessly combines form and function.

Achieving Aerodynamic Supremacy

From the project's inception, efficiency and range were high priorities for the A6 e-tron. “We placed very ambitious goals for ourselves. To be honest, we weren’t sure if we would achieve the values we aimed for,” recalls Andreas Lauterbach. Over 1,300 simulations and countless hours in the wind tunnel were essential in fine-tuning the vehicle's aerodynamics.

The exceptional results were achieved through close collaboration between the aerodynamics experts and the design team. Early on, designers shared their drafts for initial aerodynamic evaluations. In an iterative process, the teams worked both virtually and with physical models in the wind tunnel to optimize the vehicle's basic structure. The slim greenhouse and the sloping roofline were crucial elements contributing to the car’s aerodynamic efficiency.

Detailed Refinements

Lauterbach and Ghelfi, along with the design team, spent considerable time refining details. Air curtains, for example, were used to improve airflow around the front of the car. The outer edge of the air curtain intake initially impeded airflow. “Millimeter by millimeter, we reached a compromise that ultimately worked out for both sides,” explains Ghelfi. Adjusting the rear track width was another challenge, but a solution that balanced design, dimensions, and aerodynamics was found.

The lateral breakaway edges on the rear of the A6 Avant e-tron enabled a clearly defined flow stall, significantly larger than in other Audi vehicles. These aero bezels alone improved the range by 0.008, equivalent to eight kilometers. Achieving the top Cd values required attention to detail, including optimizing the switchable cool-air intake under the Singleframe, which improved the Cd value by 0.012, equivalent to about 12 kilometers.

Optimized Underfloor and Diffusers

The underfloor of the Audi A6 Sportback e-tron plays a crucial role in its aerodynamic performance. Features such as added radii, optimized stiffening ribs, and breakaway edges at critical points were implemented. The rear diffuser, exposed to direct airflow due to the smooth underfloor, positively impacts the Cd value by aiding pressure recovery.

Components such as wheel spoilers and 3D bumpers on the front wheels were individually optimized for the Sportback and Avant models using CFD analysis, improving the Cd value between 0.002 and 0.009. The large underfloor cover in the front of the car was optimized with a large radius on the air outlet, while the rocker panel and rear axle were extensively covered. These adjustments were possible thanks to excellent teamwork with project leaders and system team leaders.

Comprehensive Wheel Design

Andreas Valencia Pollex explains that today's wheels must meet not only stability requirements but also aerodynamic efficiency. The A6 e-tron features special 19” and 20” aero wheels. To achieve perfect aerodynamics, the rims are designed to be somewhat flat, allowing air to flow smoothly around the body without turbulence. A special 21” wheel with aero blades made from plastic was developed to enhance this effect. Across the entire range of wheels, the best and worst wheels in terms of aerodynamics differ by only 0.015 Cd, demonstrating that every wheel is optimized for maximum aerodynamic efficiency.

Conclusion and Evaluation

The Audi A6 Sportback e-tron sets new benchmarks in aerodynamics, combining innovative technologies with elegant, progressive design. The collaborative efforts of the design and aerodynamics teams resulted in achieving a Cd value of 0.21, the best in Audi's history.

The Audi A6 e-tron is perfect for environmentally conscious drivers who value efficiency, range, and advanced technology without sacrificing luxury and comfort. Its impressive aerodynamics and innovative features make it an ideal choice for tech-savvy users seeking a modern, high-performance electric vehicle.

Overall, the Audi A6 e-tron marks a significant step in Audi's commitment to electromobility, paving the way for a sustainable and exciting future in automotive design and technology.