In its pearlescent white and green colour scheme, two colours chosen as symbols of purity and ecology, the 308 Hybrid HDi demonstrator is the eagerly anticipated star of the environmental section of Peugeot’s stand at the 2007 Frankfurt Motor Show.

This new 308 Hybrid HDi demonstrator represents another step on the path towards the planned commercialisation of the technology in 2010.  Further evaluation of the original Peugeot 307 Hybrid HDi demonstrator in 2006 has confirmed the choice of a diesel engine, instead of a petrol engine, as the best option to provide the best reduction in fuel consumption and emissions.

The demonstrator is powered by Peugeot’s most efficient parallel hybrid powerplant to date, combined with a 6-speed electronically controlled manual gearbox.  It has a 110 bhp 1.6 HDi DPFS diesel engine coupled with a 22 bhp electric motor providing a maximum power output of 132 bhp, comparable to that of the 308 with the 2.0 litre HDi DPFS 136 bhp diesel engine. Fuel consumption in the combined cycle is 83 mpg and 90g/km of CO₂ or a reduction of 38% compared to an equivalent 308 diesel HDi model.

Compared to the previous 307 Hybrid HDi demonstrator presented in 2006, the focus of the development has now switched to concentrating on the packaging of the hybrid technology into the structure of the new 308, and to ensure its compatibility with the future Euro V emission standards. 

To ensure a competitive purchase price, priority has been given to using as many components as possible from current Peugeot vehicles. This has enabled the number of specific parts associated with the hybridisation of the 308 to be reduced by around 30% compared to the previous 307 Hybrid HDi demonstrator.

The parallel hybrid power train consists of a 1.6 litre HDi DPFS 110 bhp diesel engine and an electric motor with a continuous output of 22 bhp and a torque of 59 lb ft. The Power Train Management Unit selects the right distribution of power from both units to meet the requirements of the driver and minimise fuel consumption.

The electric motor alone is responsible for starting and driving at low speed, while only the diesel engine is used on open roads and motorways, with both units coming into play simultaneously to provide quicker acceleration. The system is fitted with a 6-speed electronically controlled manual gearbox able to operate in automatic or manual sequential mode.

To extend the battery range, kinetic energy recovered during phases of deceleration and braking is used to recharge the batteries. A special button provides access to an all-electric “ZEV” Zero Emission Vehicle mode. Operation of the diesel engine is then restricted to more pronounced acceleration phases or high speed driving. This "ZEV" mode provides total absence of exhaust emissions and noise pollution.