Peugeot Citroen airs 2.9L/100km hybrid

STRUGGLING French car conglomerate PSA Peugeot Citroen has put on a brave face by showcasing a set of bold future technologies including a hybrid drivetrain that uses compressed air rather than batteries to store energy and will become production reality in 2016.

Also among the exhibits at the PSA Innovation day, held at its research and development centre on the south-western fringe of Paris, was the company’s new modular global platform and a low-cost diesel-electric mild hybrid system that will feature on production cars from 2017.

The Hybrid Air system was developed with Bosch, which has experience in hydraulic energy recovery and traction systems for heavy trucks, and is claimed to deliver fuel savings of up to 45 per cent in city driving or 35 per cent overall.

PSA claims that in a light car such as the Peugeot 208 or Citroen C3, the system can deliver fuel consumption of 2.9 litres per 100 kilometres and CO2 output of 62 grams per kilometre.

A hydraulic pump powered by regenerative braking or the petrol engine stores energy as compressed air in a cylinder in the car’s transmission tunnel.

The stored energy is later used to power a hydraulic motor that drives the wheels through the car’s planetary gearset transmission, which alone is said to reduce fuel consumption by five per cent and provide a quieter drive than conventional units.

In zero-emissions mode, which PSA says runs for 80 per cent of urban driving but has not indicated a maximum driving range, the petrol engine switches off and the hydraulic motor alone drives the wheels at up to 70km/h, providing quiet progress.

The hydraulic and petrol engines can also run in tandem to boost performance or during low speed driving, refill the compressed air energy storage.

PSA says Hybrid Air makes full hybrid technology more affordable “to the great majority”, the pressure accumulators do not eat into interior space, that as a mechanical system it is reliable, robust and easy to maintain.

Other benefits are that the system has a smaller environmental footprint than batteries and can be produced and maintained anywhere in the world.

The new EMP2 (efficient modular platform) will underpin more than 50 per cent of vehicles produced by PSA, starting later this year with replacements of the Citroen C4 Picasso and Peugeot 308.

Compatibility with diverse body styles and weight savings of up to 70kg are promised, as is the possibility for the inclusion of new fuel-saving technologies claimed to yield a 22 per cent reduction in CO2 emissions.

The platform is also designed to accommodate the large wheels, short overhangs, low bonnets and sporty driving positions considered desirable, while delivering driving pleasure, comfort and safety.

PSA’s cost-saving Hybride Eco diesel-electric mild hybrid system is designed for vehicles at the small end of the spectrum – a European speciality – and will be included on production vehicles from 2017.

Compared with the company’s existing e-HDI system that essentially comprises regenerative braking and idle-stop technologies to reduce fuel consumption, Hybride Eco is said to save an additional 10 to 15 per cent.

The system uses a 10kW electric motor and 48-volt lithium-ion battery that can propel the vehicle for short distances at up to 20km/h and is compatible with manual or automatic transmissions.

Further up the hybrid food-chain at the innovation event was HYdole, a dual-mode plug-in hybrid system claimed to enable 80 per cent of daily journeys to be travelled on electricity alone, with a combined range of 500km.

Few details of the system were supplied but PSA expects vehicles using the system to emit less than 30 grams of CO2 per kilometre and receive a full battery charge in five hours from a 16-amp outlet.