Toyota is claiming a rated fuel consumption of 2.2L/100km for a new plug-in version of the Prius which will debut at the Frankfurt Motor Show.
The car, slated for launch next year, will use a lithium-ion battery system, which will allow 20km range in EV mode and which can be recharged in 90 minutes from mains electricity.
The car will continue with the 1.8 petrol as the conventional component of the powertrain.
A 7-seat Prius will also launch in Europe in mid-2012.