(February 17, 2013) After pioneering the diesel particulate filter system and Stop & Start, leading the way in diesel hybrid technology with Hybrid 4 and being one of the first manufacturers to market electric vehicles, Citroën continues to innovate with another high-tech breakthrough — Hybrid Air— which will be unveiled at the 83rd Geneva Motor Show next month.



A full-hybrid solution combining a gas engine, compressed air and hydraulic power, Hybrid Air delivers exceptional performance with fuel economy in excess of 94mpg and no additional batteries, ensuring a reduced environmental footprint, more affordable pricing, and no impact on cabin space.

On the Citroën stand at the Geneva Motor Show, the brand will showcase a C3 VTi 82 prototype fitted with this new technology. The Citroën C3 Hybrid Air produces CO2 emissions of just 69g/km with fuel consumption reduced by a third to achieve a record-breaking 97mpg over a combined cycle. In urban driving, fuel consumption and CO2 are reduced by 45% compared with a vehicle solely fitted with the same internal combustion engine.

The unique and revolutionary Hybrid Air system was developed by PSA Peugeot Citroën in cooperation with the Bosch Group and draws from the Citroën brand’s historic expertise of hydraulic systems for cars including;

    • The DS in 1955, which combined pressurized air with high pressure hydraulics to control and manage the suspension, steering, braking and semi-automatic gearbox.

    • A 2CV hybrid concept in 1958 that utilized pressurized air and hydraulics to boost the combustion engine. There was no real market for the car at the time and technologies were lacking for mass production, so the project never became a reality.

Hybrid Air combines proven sub-systems and technologies including a PureTech gas engine, a compressed air energy storage unit, a hydraulic pump/motor unit and an automatic transmission with an epicyclic gear train. Eighty patents were filed by the PSA Peugeot Citroën Group during the development process.

An intelligent electronic management system manages input from the driver to optimize energy efficiency with three operating modes — air power, with zero emissions; gas power, using just the combustion engine; combined power, with the combustion engine and hydraulic motor working together.

Hybrid Air combines all of the technologies, relying on the intelligent electronic management unit to switch continuously between the three operating modes. Optimizing energy efficiency in this way cuts fuel consumption and allows the system to recharge the energy storage unit with compressed air.

Active up to 43 mph, Air Mode works in the same way as the ZEV mode on existing hybrid vehicles. The combustion engine is not used. The energy stored (compressed air) is transmitted to the wheels via the hydraulic motor and gearbox.

Depending on traffic, this mode will be active between 60 and 80% of urban driving time. Maximum use of deceleration and braking energy will ensure efficient recharging of the compressed air unit.

Gas Mode transmits energy to the wheels without input from the compressed air unit. This mode is used primarily for journeys outside urban areas. Again, the energy from deceleration and braking is recovered for use when in Air Mode or for the boost function in Combined Mode.

Combined Mode, the combustion engine and hydraulic motor work together. This mode is used particularly during pick-up and strong acceleration, with a significant boost effect delivering performance comparable to that of an engine from the next market segment.