"This is quite a massive enhancement," said Elon Musk, Tesla's CEO, at a press confernce. "I wish we could have done it earlier."

Chief among the improvements in Autopilot Version 8.0 is increased reliance on the radar system in the company's Model S and Model X. The sensors have been in Teslas since October 2014, and the new software will download and run on existing hardware—although Musk says it was quite a job to get it to fit.

Autopilot builds a picture of the world around it using a forward-looking camera mounted near the rear view mirror, a radar in the front bumper, and 12 ultrasonic sensors around the vehicle. Until now, the car's computer has used the image from the camera as the primary information source.