Known for its air and hydraulic suspensions, French carmaker Citroën will apply its expertise with pressurized air to power its vehicles.
On the Citroën stand at the Geneva Motor Show, the brand will showcase a C3 VTi 82 prototype fitted with this new technology it calls Hybrid Air.
According to Citroën, the C3 Hybrid Air produces CO2 emissions of just 69 gram per kilometer; in urban driving, fuel consumption and CO2 are reduced by 45 percent compared with a vehicle solely fitted with the same internal combustion engine.
A full-hybrid solution combining a gas engine, compressed air and hydraulic power, Hybrid Air delivers, per Citroën, exceptional performance with fuel economy in excess of 94 mpg (less than 3 liters/100 kilometers) and no additional batteries.
The unique 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.
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 of Hybrid Air.
An electronic management system manages input from the driver to optimize energy efficiency with three operating modes: air power, with zero emissions; regular gas power, using just the combustion engine; and combined power, with the combustion engine and hydraulic motor working together.
The Hybrid Air system combines all of the technologies, relying on the electronic management unit to switch continuously between the three operating modes. Optimizing energy efficiency in this way is what helps cut 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.
In air mode, the combustion engine is not used. The energy stored (compressed air) is transmitted to the wheels through 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 recharging of the compressed air unit.
The conventional gas mode transmits energy to the wheels without input from the compressed air unit. Citroën said this mode is used primarily for trips 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.
In combined mode, the combustion engine and hydraulic motor work together. This mode is used particularly during strong acceleration, with a significant boost effect (total power of up to 90 kilowatt) delivering performance comparable to those of a car with a bigger engine.
Citroën believes its Hybrid Air technology has a number of benefits that make it both attractive and economically viable for a number of global markets:
- The system uses no additional batteries, so pricing will be competitive both in European and international markets;
- The technology operates at a constant level of efficiency, regardless of weather or driving conditions;
- The technology could be developed for all Citroën markets, is easily adaptable for both passenger cars and light commercial vehicles, and is particularly efficient on B & C segment models;
- The system has no impact on interior space or cargo capacity and is essentially mechanical, which simplifies servicing operations and end-of-life recycling.
The Geneva Motor Show will be an opportunity for visitors to discover the C3 Hybrid Air, a new step forward in terms of ‘Créative Technologie’.
Alongside the Hybrid Air technology itself, the prototype on show will feature new Michelin tires sized specifically (165/50 R 18) to cut fuel consumption which are designed with a particularly large diameter and a reduced width for lower rolling resistance, weight and noise.