Gasoline and diesel fuel are, by far, not the only options available in the world of automobile propulsion.
Pretty much anything that stores energy can be used to propel a vehicle, whether as chemical energy in a combustible fuel, electrochemical energy stored in a battery pack, or air stored under pressure. There have been a couple of automakers who have toyed with compressed-air motors, to varying degrees of success, but Peugeot/Citroën could be the first to combine it with a gasoline-powered motor.
Hybrid vehicles, generally accepted to be hybrid electric vehicles, make use of generators to recover energy lost during braking and store it in a battery. Then, on acceleration, the energy stored in the battery powers an electric motor to propel the vehicle forward.
Peugeot/Citroën’s Hybrid Air vehicle, instead, uses compressed-air canisters to recover energy from braking. “This breakthrough technology… represents a key step towards the 2ℓ/100km [118 mpg] car by 2020,” said Peugeot/Citroën executive Philippe Varin.
While Peugeot/Citroën is affirming that Hybrid Air technology is currently capable of 81 mpg, I can’t help but wonder how they’ve overcome the inherent inefficiencies of air pump technology, considering that an internal combustion engine is simply an air pump.
The prototype and further development is being funded by the French government, German parts specialty company Bosch, and Faurecia, a car parts company run by Peugeot/Citroën. Maybe in a couple years we will see if they can break 100 mpg using this setup.