Nissan has given the new Leaf more wind tunnel time to make it quieter, smoother, and extend the range.

Aerodynamics play a big part in automotive design, no matter what the car. But the more efficient a car gets, the more important aero can be. When you’ve maximized efficiency in the drivetrain, it’s time to make the car cut through the air more smoothly.

That’s what Nissan has done with the next generation Leaf. The company has recreated what it calls the ideal shape for the car. This lets the car slice through the air more cleanly. The result of that means a more efficient trip using less electricity.

Nissan said that the new Leaf will have zero lift. It’s also lower to the ground. Those two things improve stability at speed. Most cars generate lift at speed. Lift is an aerodynamic force that pulls the car up, taking weight off of the wheels. It’s the opposite of downforce, something that most cars need massive wings to generate. Lift makes a car unstable because the car is being pulled up and away from the road.

Zero lift makes the car more stable because there is no force pulling up and more force keeping it on the ground. It improves high-speed cornering and can reduce the amount the car is affected by crosswinds or buffeting from other vehicles. Nissan has added other design features that it said will also help stabilize the car in crosswinds. It all adds up to a better ride and more miles per watt.

The full reveal of the all-new Nissan Leaf will be September 5.