NEW YORK (AP) - Tesla Motors says improvements it's making to its older Roadster model will let the electric car travel about 400 miles on a single charge.

NEW YORK (AP) Tesla Motors says improvements it's making to its older Roadster model will let the electric car travel about 400 miles on a single charge.

The Palo Alto, California, company says a new battery and other improvements like new tires will boost the car's range 40 to 50 percent compared to the original.

Tesla says it plans to demonstrate the higher range with a drive from San Francisco to Los Angeles about a 400-mile trip early next year.

Tesla Motors Inc. CEO Elon Musk tweeted about the upgrade Thursday and Tesla posted more details on its website Friday.

Tesla stopped making Roadsters in 2012.

The company says not to expect any major upgrades in the battery or range of its Model S, introduced in 2012, "in the near term."