As we're getting closer to the Frankfurt motor show, automakers are letting out new details on their vehicle introductions. This time it's Toyota that has released information on new its Prius plug-in hybrid that will be leased to selected fleet customers around the world from early 2010 so the company can evaluate the vehicle in a real-world environment as it prepares for a potential market launch.

Building on the core technology of Hybrid Synergy Drive in which both the electric motor and petrol engine can drive the wheels, the plug-in version replaces the standard Prius' nickel-metal hydride battery pack with a compact high-output lithium-ion battery that can be fully recharged from a 230V power supply in 1.5 hours.

The new battery, which is more compact and has a higher volumetric energy than the one it replaces allows the Prius to achieve speeds of up to a maximum 62mph (100km/h) in full-electric mode (EV).

Toyota says that on a full charge, the plug-in model it can cover around 12.5miles or 20km) in EV mode, which is six miles more than the 'conventional' Prius hybrid. Over longer distances, the car switches to conventional petrol-electric full hybrid operation.

The extended range in electric mode helps reduce CO2 emission to less than 60g/km, making the plug-in model one of the cleanest cars on the road.

According to the Japanese automaker, more than 500 Prius Plug-in cars will be released around the world early next year for lease programme, with more than 150 of those destined for the European market.