AUDI is to reveal no less than four new plug-in hybrid model at this year's Geneva Motor Show with petrol-electric powertrains arriving on its A6, A7 Sportback, the A8 and the Q5 SUV.

The newcomers will have their debut on March 5 and Audi claims each of the models has a zero emission range of up to 25 miles.

The cars will be known as TFSI e models and all will be on the road this year.

Audi says the TFSI e concept brings together a turbo-charged petrol engine with direct injection and an electric motor that is integrated in the transmission.

A lithium-ion battery beneath the luggage compartment floor supplies the electrical energy.

As a result, the electric motor supports the combustion engine during acceleration producing high start-off performance and powerful acceleration.

The lithium-ion battery for the A6, A7 and A8 is made up of 104 pouch cells which are combined in eight modules. It stores 14.1kWh of energy at a voltage of 385 V.

The battery in the Q5 comprises prismatic cells and has the same capacity. A full recharge from a 7.2kW charging point will take around two hours.