Uber CEO says there's a potentially big problem with Elon Musk's Robotaxi idea

• Uber's CEO has some doubts about Elon Musk's Tesla Robotaxi plan.
• Dara Khosrowshahi questioned if Tesla owners would want strangers riding in their cars.
• He also said Musk might be underestimating the customer service side of the business.

Uber CEO Dara Khosrowshahi is skeptical about Elon Musk's Robotaxi plan.

The idea is that Tesla owners will rent out their vehicles as taxis when they aren't using them, creating a fleet of privately owned autonomous cabs that can be "summoned" at the click of a button. Musk has said it could earn Tesla owners up to $30,000 a year .

On an episode of "The Logan Bartlett Show" released on Friday , Khosrowshahi said it "wasn't clear" to him that the average Tesla owner would want "to have that car be ridden in by a complete stranger."

He also doubts that Tesla's taxis could meet demand during peak times.

"Probably the times at which you're going to want your Tesla are probably going to be the same times that ridership is going to be at a peak," he said. Comparatively, Khosrowshahi said Uber can quickly adjust the number of part-time drivers to meet demand during rush hour or large events .

Khosrowshahi also said Musk might be underestimating a key part of the business. He said building a $50,000 piece of hardware is a "very, very different business" than driving over 30 million transactions every day. There is also the customer service side of things, like when someone gets sick during a ride or loses an item in a car , he said.

But Khosrowshahi said he doesn't think of the business as a "zero-sum game" and seemed to welcome collaboration with the EV giant. He made an analogy to fast food chains, which have their own "direct channel to consumers" but also work with other platforms in the marketplace to maximize efficiency and usage — like delivery services.

Khosrowshahi said he thinks the same will be true of cars. For example, Tesla could build its autonomous vehicles and then partner with Uber to turn them into a ride-hailing service.

"It's taken us 15 years. It's taken us tens of billions of dollars of capital, and we can provide that instantly to a partner," Khosrowshahi said. "Hopefully, Tesla will be one of those partners."