Some were wondering how Tesla is going to achieve a range greater than the Bolt EV’s (200+ miles) with the Model 3 (215+ miles), even though the company confirmed the Model 3’s battery pack will have a smaller capacity than the Bolt EV’s 60 kWh pack. Aerodynamic performance was the main suspect and now the Bolt’s lead designer, Stuart Norris, confirms it by calling the Bolt “a disaster for aero” with a drag coefficient of 0.32.
The designer made the comment in an interview with AutoNews for a profile of GM’s South Korean design studio, where the Bolt was designed.
Norris said that the Bolt’s poor aerodynamic performance is not due to a lack of trying since the company put six full-sized versions of the Bolt through wind-tunnel testing before going pencil down on design.
AutoNews reports on the automaker’s work to improve airflow:
“To improve air flow, Norris’ design team incorporated a spoiler and sharply creased winglike canards along the tail edge of the car. Other tricks were underbody paneling, air dams and active grille shutters that close at certain speeds to streamline airflow. Designers even adjusted the radius of the A-pillar, modified the mirrors and fine-tuned tire coverage.”
At the end, GM decided to focus on cargo space and having a tall liftgate. In order to maximize range, weight reduction was taken into consideration and the Bolt ended up with several aluminum parts, including the hood, liftgate and doors.
It’s interesting to see each automaker’s approach to making a long-range electric car in the $30,000 to $40,000 range. In the case of Tesla’s Model 3, it seems that there was more of a focus on aerodynamic performance. The estimated drag coefficient is 0.21, but the vehicle’s C-pillar sits lower than the Bolt’s, which limits the options for a hatch. Though CEO Elon Musk said that the production version “fixed” the Model 3 prototype’s trunk problem.
The Bolt EV is expected to go in production in October and start arriving in the CARB markets by the end of the year.