Chris Woodyard

USA TODAY

Tesla Motors CEO Elon Musk says some rivals are finally taking him up on his offer to share some of Tesla's 200 patents for free.

In a controversial move, he opened up Tesla's patent book in June in a bid to try to foster more of a market for long-range electric cars. At the time, he expressed surprise that despite Tesla's success so far -- it plans on making about 35,000 cars this year -- that no other automakers seemed serious about making long-range electrics.

At first, it sounded like competitors were shrugging at Musk's offer. But at an event last week in Hawthorne, Calif., to unveil advances in Tesla's Model S electric car, Musk told USA TODAY that some rivals are starting to use the patents.

"We have had a number of inquiries from other car companies and we've told them to go ahead and use them," Musk says.

Most automakers have developed electric cars at this point, but many are limited to a range per charge of about 100 miles or less, making them impractical for most consumers. Sales are paltry. But some makers, like BMW with its i3 city car and General Motors with plans for longer range in the next version of the Chevrolet Volt, are sounding like they see a future for electric powerplants. Musk says he's welcomes it.

"I'm glad they are getting serious about electric cars -- and they should," he says.

Tesla's Model S is rated by the EPA at up to 265 miles of range per charge and Musk has developed a network of high-speed chargers around the country to encourage cross-country travel in the luxury electric sedans.

Fiat Chrysler Automobiles CEO Sergio Marchionne, in an appearance Monday on CNBC, said that the auto industry has taken Tesla's accomplishments "incredibly lightly."

"I think he deserves more attention that we have given him," Marchionne said of Musk. "In terms of the underlying business model and what he's doing, it's something we need to understand much better."

Opening patents to foster a market is a strategy that's more accepted in Silicon Valley than Detroit. Musk said at the time he made the move that he is counting on his engineers to come up with team with new innovations that will stay ahead of the company's existing patents.