PSA claims that vehicles employing this system can be 60% to 80% in ZEV mode in city driving, depending on the traffic

PSA claims that vehicles employing this system can be '60% to 80% in ZEV mode in city driving, depending on the traffic'

PSA Peugeot Citroën has developed what it describes as a revolutionary technology called Hybrid Air, a petrol and compressed air full-hybrid solution.

The basic system comprises a petrol engine, a unit to store energy in the form of compressed air, a hydraulic motor-pump assembly and an automatic transmission working with an epicyclic gear train.

It says the new full-hybrid powertrain technology will be fitted on B-segment models starting in 2016.

PSA maintains that the "Hybrid Air" hybrid set-up, which combines a petrol engine and compressed air for energy storage,  is a key step in the path toward meeting a fuel consumption target for a car of 2L/100 km by 2020. 

It says that the major innovation lies in the way the powertrain adapts to driving styles, adjusting independently to one of three modes: air, gasoline, combined. Air power would be employed at low speeds and for urban use, automatically activated below 43mph. 

PSA says that its Air Hybrid system adds about 100kg to the weight of a traditional ICE powered small car, around half of that of a conventional hybrid system. The company claims there are other advantages over gasoline-electric hybrids, such as no need for a lithium-ion battery with its associated high manufacturing costs as well as a simple design that is easier to maintain over the life of the vehicle.

PSA also claims that the use of this 'breakthrough' technology on petrol and diesel vehicles in the B-, C- and D-segments will reduce CO2 emissions by 15g and cut fuel consumption by up to 15%.

The technology has been developed in partnership with the French government and Bosch and Faurecia are also strategic technology partners in the project. 

Other manufacturers have investigated the possibility of compressed air to power cars in the past, including Tata, but there are a number of technical challenges to be overcome (air has a low energy density, has to be stored at very high pressure and has to also be heated at the point of use to minimise energy loss) and none have yet made it into series production.