Most hybrids combine petrol and electric power to lower emissions and increase efficiency, but that’s not the approach that PSA Peugeot Citroen has taken. The engine they’re developing with Bosch combines petrol and compressed air.
The French car maker is aiming to achieve economy of 141 mpg by the year 2020 from the new technology and hopes to have the Air Hybrid on the road by 2016. The powertrain, which our shots show currently being tested in a converted Citroen C3, includes a small capacity petrol engine and a unit of compressed air attached to a hydraulic motor pump which is fed through to an automatic gearbox. The car is used in exactly the same way as a ‘conventional’ petrol / electric hybrid, so there are three modes in which it can be driven – zero emissions, as petrol only or the two combined. The ECU will control the mode depending on the road conditions, but PSA expect that 60% to 80% of city miles will be carried out with zero emissions.
Without the need for a heavy battery pack, the car can be lighter than rivals with petrol / electric power. This will lead to further efficiencies and will give designers more space to work with in the cabin. At the moment the powertrain is returning 97.4mpg and CO2 emissions of 69g/km in a Peugeot 208 or Citroen C3, but further economy will be found when a chassis is designed specifically for the new powertrain.
Peugeot and Citroen will offer this technology in B-segment cars to begin with and then release it in C-segment cars like the 308 and C4. When combined with the firm’s new EMP2 platform, which is 70kg lighter than the current platform, perhaps the 141 mpg could become a realistic target.