Peugeot unveils model that will run on air

French carmaker PSA Peugeot Citroen has unveiled a petrol hybrid engine that stores energy using compressed air which it hopes will be a gamechanging technology to improve energy efficiency.

And the car giant believes it can put the innovative vehicle on the road by 2016, knocking 45% off fuel bills for the average motorist.

The engine, which allows up to 80% driving on compressed air in cities, offers fuel economy of 2.9 litres of fuel per 100km (81mpg) and emits just 69g of carbon dioxide per kilometre.