Tesla appears to be testing a car with lidar sensors, a technology used to help automakers develop self-driving vehicles.

Elon Musk famously said “lidar is a fool’s errand,” at Tesla’s “Autonomy Day” in April 2019. “Anyone relying on lidar is doomed.” Musk has maintained his company can build full self-driving (FSD) vehicles without resorting to lidar.

Despite those statements, pictures have been circulating on Twitter showing a Model Y with lidar sensors on the roof.

@JimmyPatronis This could be interesting.

— Grayson Brulte (@gbrulte) May 20, 2021

According to Bloomberg, Tesla purchased the lidar sensors from Luminar, whose stock rose as a result. What’s not clear, however, is what the company is working on. While the obvious conclusion is that Tesla is doing an about-face, experts are not convinced.

“The more likely scenario is they are using the Luminar lidars to validate their camera-based FSD system,” Guidehouse analyst Sam Abuelsamid told Bloomberg. “If they made that change, it would effectively deprecate their entire fleet of vehicles. They are not going to retrofit one million vehicles.”

One strong possibility is that Tesla is simply testing their vehicles to see how they compare with lidar-equipped competitors.