WINDSOR, Ontario — In the last year, Sergio Marchionne took a few test rides in Google’s self-driving car, and he came away impressed with the speed. But it is the breathtaking pace at which the technology is advancing, not how fast the car travels, that has really grabbed his attention.

“Each time it got better and better,” said Mr. Marchionne, the chief executive of Fiat Chrysler Automobiles, which is now collaborating with Google. “It isn’t pie in the sky. People are talking about 20 years. I think we will have it in five years.”

Mr. Marchionne was speaking at the auto company’s plant here, which is starting to make a new minivan, the Pacifica. Under the partnership unveiled this week, Fiat Chrysler will make about 100 modified Pacificas that Google will outfit with sensors and computers it has developed. The two companies will put together a joint engineering team, based in Michigan, to hone the technology.

In his first public comments on Fiat Chrysler’s agreement with the tech giant, Mr. Marchionne acknowledged it was unclear how far their collaboration will go, or how they will share the results of their work.