Toyota plans to unveil the Prius plug-in hybrid (shown) and a new, larger Prius+ in Frankfurt (Photo: Toyota)

Toyota will debut its Prius plug-in hybrid at the Frankfurt auto show next month.

The Japanese carmaker claims fuel efficiency of 2.2 liters/100km and CO2 emissions of 49 grams/km for the model, which has a newly designed and more compact lithium-ion battery.

The plug-in hybrid is aimed at both urban commuters, who will benefit from its extended electric range, and drivers of longer distances, who will need the Prius' gasoline engine, Toyota said.

The carmaker, whose Prius was the first hybrid-electric vehicle on the market in 1997, is rolling out hybrid technology across its model range.

In addition to the plug-in hybrid, Toyota will show the Prius+, a seven-seat full hybrid that will go on sale in Europe in the first half of 2012.

The Prius+ is a new model that is 155mm longer, 30mm wider and 85mm taller than the standard version of the car. Its wheelbase has been extended by 80mm.