Going green for September's Frankfurt Motor Show will be Peugeot's 308 hatchback with the world premiere of the 308 Hybrid HDi - the firm's second hybrid demonstrator model. Scheduled to enter the market in 2010, the new hybrid continues development on a comerically-viable hybrid drive system, in its present form now capable of 83 mpg on the combined cycle and emissions of only 90g/km of CO2.
Following evaluation of Peugeot's 307 Hybrid HDi, first surfacing in 2006, Peugeot have reaffirmed the choice of a diesel powerplant over petrol as being the most advantageous for reductions in emissions and fuel consumption in further development of the technology.
Now focusing on the commercialisation of the 308 Hybrid HDi, the number of specific parts associated with the 'hybridisation' of the new model has been reduced by 30 percent over its predecessor, while concentration on the hybrid's packaging into the 308's structure and its Euro V compliancy have become key priorities.
With the continued development of powertrains, impressive sets of figures have been ensured for the latest incarnation of Peugeot's Hybrid HDi. Powered by a 110 bhp 1.6-litre HDi engine, coupled with a 22 bhp electric motor and a 6-speed electronically-controlled manual gearbox, the 308 Hybrid HDi is able to trump equivalent models in the 308 range. The latest Hybrid HDi achieves a 38 percent reduction in CO2 emissions over the standard 2.0-litre HDi model, while fuel economy is 63 percent greater on the combined cycle. (To put that into perspective, that's 25 percent more fuel efficient and 15 percent cleaner than a Prius.)
To optimise fuel and emissions efficiency, the 308 Hybrid HDi employs a Power Train Management Unit (PTMU), which electronically adjusts the powertrain modes to the driver's requirements, further reducing fuel consumption, while further features ensure optimised running. When starting and driving at low speeds, the electric motor alone is used, with the diesel engine coming into operation to work simultaneously with the electric motor when further acceleration is required. For open-road and motorway driving, the diesel unit is operated in isolation.
Peugeot have also fitted the 308 Hybrid HDi with a 'zero emissions' mode dubbed 'ZEV', which swiftly shifts the car into all-electric running, producing minimal noise pollution and no emissions, specifically designed for regulated city centres. And to keep drivers up-to-date as to their green driving credentials, Peugeot have fitted the Hybrid HDi multifuction display with real-time schematic diagrams of the powertrain operating mode as well as battery charge status.
At the Frankfurt Motor Show Peugeot will showcase its new 308 Hybrid HDi, which emits just 90g/km of CO2 and reduces fuel consumption by 58% in the Urban Drive Cycle compared to a standard 308 HDi.
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.
In addition, the engine has been designed to meet the future Euro V directive which comes into force in 2009 and offers the possibility of driving exclusively in electric or “ZEV” (Zero Emission Vehicle) mode for journeys in regulated urban centres.
The excellent aerodynamic performance of the 308 hatchback and the use of Michelin’s new Energy Saver tyres, which reduce rolling resistance, help to enhance further its performance.
A step towards commercialisation
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.
A simple, automatic technology
The vehicle is started by a customary ignition key but, unlike a conventional vehicle, this does not start the diesel engine. Instead by pressing the accelerator pedal with the gearbox in automatic mode, the electric motor powers the vehicle. The diesel engine only operates when required and is controlled by a stop and start system. All the powertrain operating modes are controlled by a Power Train Management Unit (PTMU) according to the driver’s requirements.
The driver is informed in real time of the powertrain operating mode by a schematic diagram on the vehicle’s colour multifunction display. Other information is also available, such as the battery charge status or the power train operation mode.
Well equipped and without compromise
The comprehensively equipped demonstrator has all the standard equipment of a Premium Pack 308 and also includes a panoramic glass roof and the RT4 multi-media system with a retractable colour display screen. The level of standard equipment, interior space, interior brightness, dynamic qualities and driveability are no different to those of the standard 308.
General dynamic performance is also comparable to a standard 308 HDi. In-gear acceleration, however, both in town and on the open road, is improved with the Hybrid HDi. Indeed, during in-gear acceleration, the diesel engine is backed up by the electric motor which is able on demand to deliver a power boost of up to 31 bhp (and 96 lb ft of torque).
Optimised Hybrid HDi technology
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 (PTMU) 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.
Technical description of main specific components
The electric motor is of the synchronous type with permanent magnets, developing a continuous power of 22 bhp and a torque of 59 lb ft. However, intermittently its output can attain 31 bhp and 96 lb ft.
An inverter regulates the 150 to 260 volt current from the high voltage battery pack supplying the electric motor in accordance with the torque requirements determined by the Power Train Management Unit (PTMU).
A new generation battery pack has been developed which delivers an output of 200 volts. It is housed in the spare wheel well and does not, therefore, reduce the available boot volume. The batteries are of the Nickel Metal Hydride (Ni-MH) type.
A converter converts the 200 V from the battery pack into 12 V to supply the vehicle equipment in phases of solely electrical operation.
Managed braking maximises the recharging of the batteries during phases of deceleration and braking. An Intelligent control of the braking optimises the distribution between regenerative electric braking and traditional dissipative hydraulic braking. The braking management system gives priority to braking efficiency over the recovery of energy.
