A UK-government backed research project has produced a demonstrator vehicle that emits just 99g/km of CO2. The two year Efficient-C project uses diesel-hybrid technology from PSA Peugeot-Citroën, control systems developed by the UK consultancy Ricardo and battery technologies from the former defence research organisation Qinetiq.

The demonstrator, in a Citroën Berlingo, is claimed to offer a 30 per cent improvement in fuel economy and CO2 emissions compared to an equivalent diesel production vehicle, and the partners say that in a C-segment five-door saloon the same powertrain would emit only 90g/km.

The Efficient-C car has a 1.6 litre HDi turbocharged and intercooled common rail diesel and a compact 23 kW 288V DC electric motor.



Project leader Dave Greenwood from Ricardo says that the innovation has come in intelligently matching the switching between the two modes of operation to deliver the optimum fuel consumption and emissions performance.
Efficient-C has in effect six operating modes:
* Straightforward ICE operation through the clutch and gearbox to the wheels, essentially for motorway driving.
* A second mode where the motor absorbs torque from the engine, generating electrical energy and forcing the engine to operate more efficiently.
* A third mode where the motor draws power form the battery and provide additional torque to the wheels, essentially for acceleration.
* A fourth mode using only the electric drive, used for pull-away and low-load operation in town.
* The fifth mode provides regenerative braking, with the engine off and kinetic energy captured by the motor and stored in the battery.
* The sixth mode has the battery charging with the vehicle stationary and allows the use of electrical equipment such as air-conditioning.



Ricardo, Qinetiq and PSA Peugeot Citroën were picked in 2003 to go forward in the UK Department for Transport’s ultra low carbon car challenge (ULCCC). Grants for the project were administered by the Energy Saving Trust.





Peugeot spells out affordability problem