Peugeot 208 HybridAir 2LPeugeot is pushing technology to the max for next month’s 2014 Paris Motor Show with the clever hybrid fresh air system that underpins the French firm’s 208 Hybrid Air 2L concept.

It’s got a point, too, as the prototype supermini is unlike any other hybrid on sale today. Yes, it uses a frugal combustion engine, and yes, it uses a motor to supplement the petrol powerplant’s output. However, that motor is powered by fresh air, not electricity.

Explained: Peugeot’s Hybrid Air technology

The headline is that Peugeot’s Hybrid Air tech helps the 208 concept to deliver miserly fuel consumption of 141mpg – or 2l/100km, hence the car’s full name.

It’s actually very clever, too, as it means the car doesn’t have to carry expensive, heavy and bulky battery packs, dramatically reducing the impact on weight, vehicle dynamics and efficiency.

The Hybrid Air system comprises:

  • Compressed air tank located below the boot
  • Low pressure air tank near the rear axle acting as an expansion chamber
  • Hydraulic system consisting of a motor and a pump in the engine bay

The compressor fills the main air tank when slowing down – either by pressing the brake pedal or just coasting when off the throttle.

It can also be filled by using the on-board three-cylinder petrol engine to drive the compressor, with both methods achieving maximum air pressure in the tank in just 10 seconds.

The car can then run in one of three modes:

  1. Air mode is the zero emissions setting that allows the 208 Hybrid Air 2L concept to run on compressed air alone – this does mean that although it emits the pure, fresh and clean air after it’s been used for propulsion, it doesn’t emit any polluting CO2. Good for town centres.
  2. Petrol mode isolates the Hybrid Air system, meaning the 1.2-litre three-pot engine is the only form of propulsion here – this setting is more for steady state cruising at higher speeds on main roads and motorways, says Peugeot.
  3. Combined mode does what it says on the tin, using a mix of petrol and compressed air power to fire the 208 around. This setting has been calibrated for “transition phases in urban environments” – that’s pootling around town between traffic lights and to or from the shops, work or school to you and me.

On top of this, there’s a special “epicyclic” automatic transmission that handles how the two different types of energy are deployed.

Peugeot 208 Hybrid Air 2L: save weight to save fuel

One of the biggest efficiency killers is weight – the more of it you have to move, the more fuel and energy you have use. Which is why Peugeot has sent its standard 208 supermini on a diet for the Hybrid Air 2L concept.

The outcome of the weight loss plan is a 100kg saving over the lightest 208 variant – itself a featherweight – meaning the Hybrid Air 2L tips the scales at just 860kg.

This has been achieved through a mix of three key materials:

  • Steel
  • Aluminium
  • Carbon composites

These lightweight carbon composites are employed for the body panels, sides, doors and roof, as well as for the suspension’s coil springs. A clever development indeed, which actually helps reduce unsprung mass and improve handling.

These body parts have also been aerodynamically tuned to reduce drag, helping the 208 Hybrid Air 2L cleave the air with razor-like efficiency.

Steel has to be used in key areas for safety, but alongside using new materials, Peugeot has also concentrated on redesigning parts made from conventional resources. For example, the stainless steel exhaust system is now much thinner, making it 20% lighter than before.

Overall, it’s an integrated approach to a high-efficiency hybrid that doesn’t use expensive battery materials. Granted, it can’t be plugged in and be pre-charged just yet (that could come in time) but the technology is no doubt interesting and, returning 141mph, no doubt effective.