Toyota unveils plug-in hybrid, to test on roads

By Chang-Ran Kim, Asia auto correspondent

TOKYO (Reuters) - Toyota Motor Corp. (7203.T) unveiled a "plug-in" hybrid car based on its popular Prius model on Wednesday, saying it would test the fuel-saving vehicle on public roads -- a first for the industry.

But the world's biggest automaker said the car, called the Toyota Plug-in HV, was not fit for commercialization since it uses low-energy nickel-metal hydride batteries instead of lithium-ion batteries believed to be a better fit for rechargeable plug-in cars.

Unlike earlier gasoline-electric hybrids, which run on a parallel system twinning battery power and a combustion engine, plug-in cars are designed to enable short trips powered entirely by the electric motor, using a battery that can be charged through an electric socket at home.

Many environmental advocates see them as the best available technology to reduce gasoline consumption and global-warming greenhouse gas emissions, but engineers say battery technology is still insufficient to store enough energy for long-distance travel.

"It's difficult to say when plug-in hybrids could be commercialized, since it would depend largely on advances in battery technology," said Executive Vice President Masatami Takimoto, in charge of Toyota's powertrain technology, told a news conference.

The Toyota Plug-in HV, which is due to be tested also in the United States and Europe, has a cruising range of just 13 km (8 miles) on one charge, even with its trunkful of batteries.

Detroit's General Motors Corp. (GM.N) and Ford Motor Co. (F.N) are also working on plug-in hybrids, with cooperation from battery makers such as Germany's Continental AG (CONG.DE) and Korea's LG Chem (051910.KS)

GM in January showed a concept version of the plug-in Chevrolet Volt that would be powered by a lithium-ion battery. It has set 2010 as a target for production.