Chevy Bolt design sacrifices aerodynamics in favor of cargo space

Most GM designs use separate teams for interior and exterior design, but for this pivotal project, one team did it all. Stuart Norris, the lead designer of the 190-worker South Korean design center team, said, “We broke the mold on the Bolt EV. We need to sell more of these electric vehicles, so we need something that has more broad mass appeal,” Norris continued. “The Bolt was a very significant program for us.”

Aerodynamics was a key consideration, especially since the firm is aiming for greatest range per charge with a compact electric vehicle that had a crossover hatchback design for maximum cargo capacity. According to Norris, however, “It’s a disaster for aero.”

The team put six full-size versions of the Bolt in wind-tunnel testing. They modified, added, adjusted, and fine tuned, but the Bolt still ended up with a drag coefficient of 0.32. The Toyota Prius has a coefficient of 0.24. Lower drag coefficient numbers are better, not just for looks, but for fuel economy.

The Bolt’s relatively high drag coefficient explains why, even though its battery pack is more powerful than the Tesla Model 3’s, it has a 200-mile driving range, compared to the the Tesla’s 215-mile range, according to Electrek. The Tesla has a coefficient of 0.21,

In other Bolt-related news, prototype versions of the EV are heading to Scottsdale, Arizona for self-driving technology testing. After General Motors bought self-driving company Cruise Automation earlier this year, the same pre-release all-electric Bolts were tested with camera and lidar (laser detection) sensors. The initial plan for semi-autonomous Bolts will be via GM’s partnership with ride-sharing company Lyft, possibly as early as the end of this year. Eventually, of course, the plan is to develop totally driverless, SAE Level 5 vehicles deployed to pick up and deliver riders.