Three sedans are contending for most aerodynamically efficient EV.
The Mercedes-Benz EQS large luxury sedan has a drag coefficient of 0.200, making it the most aerodynamically efficient production Mercedes car yet.
The new Lucid Air sedan, which won Motor Trend's Car of the Year award in November, has a 0.200 Cd.
Tesla claims the new Model S Plaid, which can reach 60 mph in under two seconds, is the most aerodynamically efficient production car on the market, with a 0.208 drag coefficient.
The figures for these cars are not an apples-to-apples comparison, though, because different wind tunnels yield different results, test procedures vary, and the figure used to derive the drag coefficient rating is based in part on the car's frontal area, which can differ from vehicle to vehicle.
Still, the lower the drag coefficient, the less power it takes for the drivetrain to move the vehicle and the farther it can go on a charge.
Mercedes-Benz engineers calculated that reducing the Cd on an EV from 0.23 to 0.22, would yield a 2 percent increase in driving range at 56 mph, which adds about 9.3 miles of range to a charge.
Tesla says that a 10 percent improvement in aerodynamic efficiency yields a 5 to 8 percent increase in the range of one of its vehicles.
For Lucid's Air sedan, low aerodynamic drag played a key role in meeting one of CEO Peter Rawlinson's major goals: a 500-mile range between charges for one version of the car.
To help achieve that, the California startup hired Jean-Charles Monnet away from the Red Bull Formula One racing team to head Lucid's aero development.