Citroën latest manufacturer to unveil a car that can run on compressed air
Just a few days after Renault showcased its hugely impressive Eolab concept and Peugeot unveiled its 208 HYbrid 2L, Citroen have followed suit by showing off its C4 Cactus AIRFLOW 2L concept. Based on the well-received C4 Cactus, the AIRFLOW 2L gains improved aerodynamics and a new powertrain combining a PureTech 82 engine with a Hybrid Air technology. Compared to the model on which it is based, fuel consumption has been reduced by 30%.
The Citroen C4 Cactus AIRFLOW 2L is also 100kg lighter than the production version, thanks to the widespread use of lightweight, high-performance materials like carbon fibre, aluminium, high-yield steels, composite materials and translucent polycarbonate.
But whilst weight is one of the primary saving measures, the second most important factor is aerodynamics – and Citroën haven’t neglected this either. All-in, the concept is 20% more aerodynamic than the production version. So, how have Citroën achieved this?
Well, at the front sits a re-profiled front bumper containing three air intakes that automatically open to cool the engine if it is required. If not, they will remain shut, thus improving the car’s aerodynamic properties. At the rear, there is a larger rear spoiler. The driver and passenger door mirrors have been replaced by slender rear-view cameras. The large 19-inch wheels contain active shutters to further improve air flow and are fitted with ultra-low rolling resistance tyres. The final alteration is the LED front and rear lights which, Citroën say, consume very little power and therefore directly benefits fuel economy.
The combined result of these weight saving and aerodynamic measures is that the C4 Cactus AIRFLOW 2L has a fuel economy of 141.2mpg – a figure that is not too far off the Mitsubishi Outlander PHEV plug-in hybrid, and a figure which, as the name suggests, uses just two litres of fuel for every 100km driven. This is very impressive, especially when you consider that the fuel efficient standard production model – the 1.6-litre BlueHDi diesel - already boasts very impressive fuel economy of 91.1mpg and CO2 emissions of just 82g/km.
However, unlike the Mitsubishi, there is no complicated plug-in hybrid system. Instead, under the bonnet lays an 82bhp 1.2-litre 3-cylinder PureTech petrol engine mated to a compressed air energy storage unit, a hydraulic pump/motor unit and an automatic transmission with an epicyclic gear train. The concept is able to be driven as a traditional petrol engine, on pure air power or a combination of both the traditional combustion engine and the compressed air.
The Citroën C4 Cactus AIRFLOW 2L concept will make its public debut at next-month’s Paris motor show. Although strictly a concept car, the French company says that many of clever technologies which it showcases, will be used on production versions in the not-too-distant future.
This is an abridged version of an article especially prepared by First4Auto on behalf of EcoCars4Sale.