Audi is pulling out all the efficiency stops on its upcoming electric e-tron SUV. It's currently slated to be the first production car to offer cameras in place of exterior rearview mirrors.

Exterior mirrors have always been a bane to automotive engineers trying to improve efficiency (not to mention reduce wind noise.) In an electric SUV, that's particularly critical. Audi claims that every improvement of 0.01 in drag coefficient adds about 3 miles to the range of its electric SUV. Typical side mirrors add between 0.015 and 0.03 to the drag coefficient, so the e-tron could eke out an extra 5 to 9 miles of range by eliminating the mirrors.

Like traditional side mirrors, the cameras will be mounted at the base of the front windows. The cameras look almost like tiny jet engines in little nacelles standing off the front windows.

2019 Audi e-tron electric SUV

The camera systems will shave 5.9 inches from the width of the car and reduce wind noise as well as drag, Audi says. The image from the driver-side camera will appear on a screen between the door and the instrument cluster.

Audi isn't stopping there, however, The e-tron will include active grille shutters (even electric powertrains need cooling), dimples across the bottom of the car that reduce drag, active air suspension to lower the car on the highway, and new tires that have required load, heat, and size information etched into the sidewalls instead of embossed and protruding.

READ THIS: Audi details battery for 2019 e-tron electric SUV

The exterior cameras will be optional in Europe and elsewhere around the world but are not currently legal in the United States.

The United Nations has passed a convention to allow side cameras to improve fuel efficiency, but the U.S. has not adopted it yet.

Some Cadillacs already offer a camera-based center rearview mirror, with a wide-angle lens that the company says reduces blind spots. It has received mixed reviews from drivers. Some find it more difficult to use.