Following the enthusiastic response from its electric Roadster (pictured), Tesla Motors is working on a sedan. The new four-door model is tipped to share similar dimensions and performance with the BMW 5-Series, which, as the benchmark sports sedan, is a pretty ambitious target.

The Tesla sedan will have the electric motor and batteries up front, sending power down the rear wheels. Two powertrain options are expected to be on offer, the smaller featuring a range of 200 miles, and a more powerful version with a 300-mile range. Unlike the Roadster, with a Lotus-built aluminum structure, the sedan is expected to be made of steel. Tesla figures on building 10,000-20,000 sedans each year and will be sold globally.

Along with the sedan, the roadster will undergo an update by 2010, at which point the more powerful engine from the higher-end sedan will also likely be offered in the two-door, giving it some serious punch.

It's a pretty shrewd move on Tesla's part to have made the Roadster first, in the process garnering some excitement over a sportscar before branching out into more practical applications.

[Source: PistonHeads]